LiFeBlueBattery
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Posts posted by LiFeBlueBattery
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17 hours ago, Overland said:
Exactly. Here’s a chart from a 30 minute trip I just made. This is from the battery monitor on an AGM house battery that I have under the back seat of my truck. It’s connected to the starter battery with 2 awg cables and a Victron Cyrix smart relay. I have a 12 volt fridge attached to the house battery, which is the amperage load that you see on the chart. I had auto start/stop disengaged.
In this case, I had just made another short highway trip that had already fully charged my start battery, so you don’t see a prolonged period at 14.6+ volts are the start. The house battery was at about 85%. You can see that the voltage goes into the 14’s for just a brief period before settling in at 12.8 or so. The spikes at the beginning of the drive are in stop-go traffic. (The truck has electric assist on the brakes so those are the spikes.) You’ll see that it evens out for a bit once I get in the highway, but then jumps suddenly to around 13.4 volts. That’s when I turned on my headlights. (BTW, that’s been a GM owners trick for a while to get their voltage up to a charging level.)
So you can see that modern electrical systems only provide the voltage that the truck needs at any given time. They do this regardless of what other load you add to the system. Unfortunately, while I may be able to trick the system into providing 13.4 volts, that isn’t enough to charge lithiums, since I’d probably only see 13.2 or less at the battery. So yes, a B2B charger is absolutely needed.
I believe I see the flaw in your test. An AGM battery at 85% SoC will draw low current. The #2 wire may also have high voltage drop thus reducing current output. A great test will be to apply a 100A continuous load on the house battery and drive again. I could be wrong here but the higher load should trigger the DC voltage to rise as it attempts to deliver demand current.
The E-Torque 48V battery can not be maintained at 100% SoC as it is used for engine braking also. With low loads it must stop charging or reduce charge current to maintain the proper SoC. Their must always be "room" in the battery for the regenerative braking. This reduction may also affect the DC converter output but only momentarily as the controller regulates the 48V SoC.
This is my understanding but I'm no expert on that system.
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1 hour ago, mjrendon said:
Larry,
Thank you for responding with LifeBlue recommendations.
My understanding is that typical alternators produce 15 volts for charging the lead acid battery. It would seem that 14.5 volts from the trailer would not be unusual because of this.
I was referring to modern vehicles with complex electrical systems. Back feeding high voltage when the engine is not running may trigger fault codes or worse may be harmful.
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4 hours ago, bhncb said:Leaving the charge line disconnected may have been advised by Lifeblue to shield them from liability for battery damage due to inadvertent discharge by leaving a tow vehicle connected. Short sighted but certainly the cheapest way out.
LiFeBlue Battery did not make any recommendation to leave the charge circuit disconnected. We did advise that the customer install a disconnect solenoid as shown in our auxiliary charge circuit diagram. See example of the solenoid in attached photo.
We do not recommend connecting the 7 pin charge circuit without an isolation device controlled by the ignition. Your trailer charging system can reach 14.6 Volts. This voltage would be connected to the tow vehicles electronics. Check with your TV manufacturer for their recommendation.
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1 hour ago, Fritz said:
....So my question is this: Is charging the LifeBlue batteries from the TV "simply" a matter of having a large-enough wire to carry adequate current to the trailer (and from the front of the trailer to the batteries), or is there a benefit from an external DC converter (which is what I understand the Redarc charge controller does) to fully top off the batteries. Larry, if you see this, perhaps you could weigh in on why you don't recommend an external DC converter.
Hi Fritz,
Yes, a large enough wire and the other components is all that is needed. The charging system we recommend in the diagram has been used successfully by us for nearly 2 decades in every kind of tow vehicle. The DC converter you linked to only supplies 12 Amps maximum. That will take a very long time to charge the batteries.
I view DC converters like this: you have 100 feet of 1/2" garden hose. You only get a trickle of water out of the end. You want more water (power) so you buy a high pressure pump (DC converter) to try and boost the water volume (current), stressing the hose in the process. Why not just use a larger hose (wire)?
Someone was asking about the E-Torque system. It has a 3 kW 48~12 DC converter. This is used to recharge the chassis battery and provide for all 12 Volt vehicle loads. There should be ample power for charging the house battery. I recommend consulting with the manufacturer as to where to tie in to the 12 volt system for auxiliary battery charging.
I know there was much discussing in this thread. Let me know if there is a specific question and I'll try to help.
Happy Trails!
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1 hour ago, NCeagle said:
That's a great question (again) because the situation has changed. In a past post with @LiFeBlueBattery(Larry), the design was that when the internal battery temp was below 32F the current coming in was redirected to the heating pads. Meanwhile, the battery BMS keeps "cycling" until the temp is high enough and then it starts accepting charge. With the auto-warming now disabled and the manual heating pad, I'm not sure where any charge current would go. Hopefully the battery has an internal cutoff. I'll send an email to LifeBlue Larry and ask. I want to know now.
Hi John and Anita,
All LiFeBlue Battery models have low temperature charge protection. Oliver is currently using our Standard battery. If the cell temperature is below the protection temperature threshold, the BMS will do one of two things: 1) If the charge current entering the battery is 0.05C or less, the BMS will pass current to the cells. For the 200AH batteries, that is 10 Amps per battery. This low current is not harmful. 2) If the current exceeds 0.05C, charge current is blocked until the release temperature is reached.
Any charge or discharge current will produce some heat in the battery, primarily from the FET's on the BMS.
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2 hours ago, SeaDawg said:
That was my thought, too. That the charge wizard on on progressive dynamics drops into a float charge after the battery is unused for a period of time.
I've not actually observed that, since we're almost always powered by the solar panels.
Here's the 4 stage routine that the PD Charge Wizard performs.
BOOST Mode When you first power on, full current until you reach 14.4 Volts.
NORMAL Mode 13.6 Volts after the Boost voltage is reached. (I'm not sure how long this cycle is)
STORAGE Mode 13.2 Volts – Maintains charge with minimal gassing or water loss.
EQUALIZATION Mode 14.4 Volts – Every 21 hours for a period of 15 minutes prevents battery stratification & sulfation. After the 15 minute of charge, the converter returns to CV Float mode that they call storage.PD terms can be confusing.
"Boost" mode is usually called Bulk mode by other manufacturers. It is unregulated voltage and current.
"Normal" mode is like the Absorb mode but they use a reduced voltage.
"Storage" mode is normally called Float mode.
"Equalization" mode is not equalizing batteries as the term is normally used. Equalizing flooded LA batteries is done by applying a high voltage charge of about 2.58 volts per cell while monitoring the specific gravity of the cells. This is very beneficial to flooded battery life. I also recommend a short (15 minute), daily equalization charge for AGM batteries for the longest life. All customers that have practiced this have had the longest lasting batteries, some over 13 years.(Note: None of this is related to charging LiFeBlue batteries.)
Larry.
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2 hours ago, Jim_Oker said:
That's interesting input and makes sense. For lithium batteries, I've read in a few places (including I think here from the LifeBlue rep) that it's best to store the batteries with roughly a 50% charge on them, and that if they're disconnected from any phantom loads that will maintain fairly well for quite a long time. It would be nice to be able to simply leave them connected with the charge controller set to "dormant/storage" such that it simply tops them off as needed to keep them at roughly that level of charge.
Hello Jim and others,
Jim, you are correct. The best method for storage of LiFeBlue Battery is discharge to about 50%. That should be above 13.1V. Disconnect from everything and check voltage with the Bluetooth App periodically while stored. Recharge if voltage drops below 13.0V. A battery disconnect switch (see image attached) can be connected to the positive terminal to make storing or servicing easy.
As far as the PD converters with built in charge wizard go, they take good care of lead acid batteries, be they flooded or AGM. After charging, every 21 hours, a high voltage boost charge happens to help dissolve lead sulfate that forms on the less active portions of the plates while in constant voltage Float mode. There is no need for any other chargers if you leave AC power on with the PD converter.
A PV solar system controller that is 3 stage can also maintain LA batteries pretty well. I recommend a high voltage equalization stage every 1-2 months while stored to reduce level 2 bonding of the lead sulfate. That happens when the amorphous powder begins to form a crystal structure. If this is not dealt with, the battery will become irrevocably damaged. You can tell the battery is damaged by bulging of the case and pushing upward around the positive post as shown in the second image.
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6 minutes ago, bhncb said:
....the DC charger (converter) section in the Progressive Dynamics power distribution center has to be replace with a Lithium compatible model.
Hello, I posted before seeing your response. Please review my post above. The converter does not have to be replaced if you can use the on board button, Charge Wizard or Pendant. If you always want automatic charging, you will need to replace the converter.
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31 minutes ago, ysmroth said:
DO LIFEBLUE BATTERIES WORK WITH THE ZAMP CONTROLLERS AND PROGRESSIVE INDUSTRIES CHARGERS?
LiFeBlue Battery can be charged from any power source within the voltage and current range specified. Nearly all PV solar controllers have multiple modes. If it has a Li-ion mode, you can use that. If not, we recommend using the GEL battery mode for 2 reasons. #1) Temperature compensation is defeated as a GEL lead acid battery can be destroyed quickly by high voltage. #2) GEL settings float at 13.8 Volts which will keep the battery topped off until the sun sets.
Did you mean to ask about "Progressive Dynamics"? PI makes surge adapters and other products; PD makes converters. The PD multi-stage models generally will not work because they sample voltage before starting. Because Li batteries operate at higher voltages, this and other brand chargers think the battery is full and starts in the Float mode. Some have control boards with a button that allows the user to change to the Boost mode which will charge our battery. Other models have a port for external Charge Wizard or the Pendant. Each of those have a button to change charge mode.
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Hello George,
Here's a link to the data sheet on the LiFeBlue Battery website: http://www.lifebluebattery.com/ewExternalFiles/LB12200-HCLT Data Sheet.pdf
The low temperature battery was introduced about 1-1/2 years ago. It is the same as our standard 200AH except it has the heater circuit. The latest version, and the one that OTT uses, is model LB12200D-LT. This version has an RS-485 data port built in for programming and future use. We have been selling our batteries for about 4 years now.
Our OEM is Shenzhen Topband Battery Co. and they design and manufacturer our cells and custom BMS. Topband has developed Li-ion batteries for over 13 years. They have worked with us to consistently improve our battery features and quality. You can learn more about our manufacturer in the attached video.
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21 hours ago, NCeagle said:
Ok, thanks Larry. So with the package that Oliver is providing (2 x 200 Ah LT LifeBlue's), when the battery is cold enough (which should be very rare), we need to be sure we are charging the LifeBlues with something under 20 amps or over 24 amps - but not in between. My 180 watt solar suitcase produces 10 amps in maximum sun. My generator can push 15 amps sustained. Looks like it would be wise to know the amps on the various charge sources in case I have to mix and match to avoid that "gap". Anyone happen to know how many amps the 340 Watt solar panels on the roof of the Ollie can produce in full sunlight? I'd guess it's around 19 max.
Hi NCeagle,
If your generator can produce 15 Amps AC (assuming you meant this), then you can easily power the Xantrex charger for the needed amperage. I think the gap is insignificant unless you are only relying on PV solar power.
340 Watts of PV solar power in ideal conditions (high irradiance, low angle of incidence, cool cell temp) can make over 20 Amps.
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39 minutes ago, Susan Huff said:
No restrictions on the amount of energy provided by other sources, but it is possible the cost of the batteries used to store solar energy might have to be prorated if they are charged from sources other than solar. Makes sense, if you think about it.
I will research the details and report any findings.
OK. Here's a fact from our business over many years: No customers has ever told us that they could not use the credit because the alternator or generator or shore power also charge the batteries. Customers wrote to thank us for the ITC info. They had never heard of it. They all used the full amount for the credit and were grateful for the $ thousands saved. I understand your wanting to research so I hope this is helpful.
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1. RE @NCeagle's concerns about prolonged charging at 100%, I know that Battleborn batteries have a higher capacity than labeled and that their BMS is supposed to keep their batteries within a range that will prolong their life. Do you use a similar tactic or should owners be cautious about charging your batteries to 100% or depleting them to 0?
I did notice that you recommend that owners deplete their batteries to 50% if being stored for longer than 30 days, whereas Battleborn recommends charging them to 100% before disconnecting.
2. Is your BMS software upgradable via your app? Are there any user controllable parameters for your BMS? Does the software provide any insight into battery health, cell balance, etc., or does it just give info on state of charge?
3. For those of us with programmable chargers, what do you recommend for absorption and float voltages, charge current, absorption time, etc.?
4. I've read that Battleborn says that the main difference between their batteries and yours is that they use a cylindrical cell vs a prismatic one. I haven't a clue about the two, but Battleborn reportedly says that in their tests the cylindrical cells lasted longer and were easier to keep balanced. What is your response to that?
5. The simplicity of these types of batteries with a built in BMS is a sword with two edges; i.e., there's more to go wrong and if it does, then you've lost the whole battery. You guys have doubled down on that by including bluetooth and heating inside the box and I'm wondering are either of those, or your BMS repairable, or worth the trouble to get repaired even if it is?
Hello Overland,
While I would enjoy having a discussion that compares LiFeBlue to other brands, I told Oliver TT that I would not do that on the forum. You’ve asked many questions that are answered on the website and in the data sheets. I’ll try to keep my answers brief. The data sheet is found here: http://www.lifebluebattery.com/ewExternalFiles/LB12200-HCLT Data Sheet.pdf
Charging, protection
The LiFeBlue BMS fully protects our battery cells. When the battery is full, It will will block all charge current coming in if any cell becomes saturated. This happens at 3.8 Volts. The charge inhibit function will latch until you begin to discharge the battery. The maximum rated voltage of our cells is 4.2V and our BMS keeps cells well under this limit. No harm happens to our battery by fully charging.Charge Profile
LiFeBlue Battery BMS was designed with a broad input for voltage and current. They can be fully charged with any voltage from about 13.6V up to 16 Volts. We recommend about 14.4 Volts Absorb or CV for about 15 minutes, then reduce CV to float at 13.8 Volts. There are many other profiles that will work with out BMS.DischargingYou can fully discharge (100% DoD) our battery without harming it also. Our low voltage cutoff happens when any cell group drops to 2.8V. The battery will enter sleep mode by disabling the MPU including Bluetooth. Current draw is reduced to 0.0005 Amps (5 micro-A).Storage,There are many aging studies indicating that storing an LFP battery at 100% will reduce cycle life much faster than storing at 50% or lower. Capacity retention is greater when storing at 50% SoC due primarily to increased positive electrode oxidization.
Capacity
We have noticed that our cell manufacturing process has increased energy density by about 5% to 10% in the last few container loads we have received. Our 300AH can have up to 330AH of stored energy.
BMS firmware
Our BMS can be updated only by us. The user can not access this feature with the user App.
App
The app has many functions. Renaming the battery is the only change you can make with the App.
See the App page here: http://www.lifebluebattery.com/smart-connect-details/index.htmlCellsIt is cheaper and faster to make a cylindrical cell than a prismatic cell. We use 25AH prismatic cells which cost more to produce than cylindrical cells. Like cylindrical cells, we use series and parallel connections but we have far fewer parts in each battery. We believe this means fewer points of failure over the life of the battery.For the last 2 decades I have done a lot of study on battery chemistries and have not seen any evidence that a LFP cylindrical cell will last longer than a prismatic cell. Let me know if you have found such a study. Our cells have actually been lab tested and with 1C discharge rate produced over 2800 cycles with 83% remaining capacity, the highest rating in the industry. Most Li batteries only claim 2000 cycles with 80% remaining.You said, “...a built in BMS is a sword with two edges; i.e., there's more to go wrong and if it does, then you've lost the whole battery.” One of our many innovative designs is that our battery is fully repairable at any time in its life cycle. If the BMS or a cell fails, even if it's many years from now, we can still repair it so you can continue use until it is spent.Currently drop in RV type Li batteries are made in China, Korea and Japan. None are made in the USA. There are many companies importing very cheap Li batteries. We choose not to go the route of cheapest price. Our goal is to have the highest quality battery that is also feature rich and the longest lasting. We have made many innovations such as our Bluetooth communications, high output BMS, low temperature batteries and so on.I hope this has addressed many of your questions.-
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28 minutes ago, NCeagle said:
Hi Larry, for a pair of 200 Ah LifeBlue Batteries, does .05C equal 20 amps (.05 * 400)? And... what current is required for the heater circuit to activate? I guess it would be up to the owner to make sure the charge source wasn't trying to charge the batteries at a rate between .05C and whatever the heater circuit is? That would be bad luck resulting in no charging. 😞
That is correct. Up to 10A per battery will bypass the heater circuit. That means with PV solar power, you can be charging in early morning, not wasting the power. If current rises above the threshold, the battery will stop charging and turn on the heater circuit.
Each battery requires 12 Amps to turn on the heater. If your PV solar can not produce enough current, the battery heater timer will start. You are also correct, there may be a period where the battery heater will not be on but the current is too high to charge the cells. This is another reason I recommend installing the auxiliary charge circuit from the alternator. Of course, a generator of shower power can also be used and the heaters will turn on.
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51 minutes ago, Overland said:
Thanks - that makes much more sense. Can you tell us how many amps the heater pulls when engaged?
Also, since you mentioned the latest BMS, is that something that's upgradable via your iPhone app?
Hi Overland,
The LB12200D-LT requires 12 Amps DC to turn on the heater circuit. If sufficient current is not available, a 10 minute delay timer will start. Note that low current from your PV solar system will charge the battery at any temperature down to -4°F.
The BMS firmware can be updated by us (in our service center) via the RS485 data port on the top of the battery.
Here's a teaser: We are currently developing a Comm box with WIFI to connect our battery to an internet connected router. You will be able to monitor your battery from anywhere using our new App. And, it will send important push notifications to your phone. This is just another step in our commitment to offer the most innovative battery.
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1 hour ago, Susan Huff said:
My tax advisor has found language that suggests, in order to take the full credit for the battery cost, 100% of the battery charging has to come from the solar panels. If not, the credit (for the cost of the batteries) must be prorated based on the percentage of charging that is solar vs alternative sources (120v, generator, or TV alternator). Like most tax laws, the language is vague, at best, and can be interpreted in many ways.
I'm not certain you could definitively determine this ratio. I suspect the tax laws are written for permanent structures; since it has been ruled that RV's are considered a second home for tax purposes, perhaps the laws will be rewritten to account for multiple sources of charging power. It will probably end up like claiming a vehicle for business use: we'll be expected to keep a log of the source of all charging. Sounds like a great way to enjoy "Oliver Time"!
The language in the ITC law is the credit may be taken for all the PV solar power system components installed in any "dwelling unit". There are no conditions on how long you live in the unit or whether all of your energy is made by the energy system for which the credit was granted. In other word, the entire system with labor cost receives the credit.
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1 hour ago, Overland said:
I don't get that. You can stick a 12 volt heat pad to the side of the battery box for $40 if needed. And with Battelborns, you'd only need it if it gets into the mid-20s. The 120v requirement for charging the LifeBlues in even moderately cold temps would be a deal killer for me - it makes your solar worthless in the cold.
Hi Overland, As mentioned in another response, our battery does not need 120Vac to operate the heater. Any sufficient current 12 volts source will work.
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1 hour ago, Overland said:
... But it looks to me like the LifeBlues may even be a bit more difficult to maintain. You'll have to disconnect and check them like I do, but you also have to discharge them to 50% after each trip. But worse, if you think it's going to get over 100° in the battery box, which is definitely a possibility anywhere in the south if you leave your trailer in the sun, you have to remove them and store them inside? That's not easier, and I wonder what effect that has on your warranty. I mean, it's easily possible that they could get over 100° without you even knowing it, and if the BMS keeps track of that, do you lose your warranty?
As far as bluetooth battery monitoring goes, you can add that to any battery bank for $150, so that's nice to have but easily gotten otherwise. And arguably there's an advantage to having a separate monitor....
Hi Overland,
A few corrections are needed.
1) There are many studies that have been done establishing the fact that storing any Li-ion battery at 100% SoC will cause faster degradation by corroding the positive plate. This will shorten cycle life. One study has shown that storing at 100% SoC AND keeping in high temperature will rapidly decrease capacity. Therefore we recommend keeping the battery as cool as posible and long term storage at 40%-50% SoC.
2) LiFeBlue Battery does not need to be removed to be stored if temperatures are above100°F. However, as stated above, cycle life will suffer.
3) LiFeBlue Battery 10 Year Limited Warranty has taken these factors into account. Simply keep the battery within the specified parameters on the data sheet.
4) A separate battery monitor will not show you many thing happening internally. If your battery has turned off at 2AM, you cant tell why. With LiFeBlue, just open the App to see what happened. Here's a list of what our internal monitor will display:
App display for Event Protection:
High Cell Voltage
Low Cell Voltage
Over Current Charge
Over Current Discharge
Low Temperature Charge
Low Temperature Discharge
High Temperature Charge
High Temperature Discharge
Short Circuit ProtectionBattery Warming (low temp models)Hope this helps.
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1 hour ago, AndrewK said:
There seems to be concern for the need to have heated LiFePO4 batteries.
I too was concerned before I installed our Battle Born batteries. I thought about drilling holes in the compartment, to allow air to flow from the basement into the compartment and installing a heating pads. From our experience, neither have been necessary.
I did seal the four holes on the battery compartment door and installed a single layer of the same insulation Oliver uses on the basement compartment door.
We have camped in temperatures down to 16 degrees and exterior of the batteries have never gone below 49 degrees.
Andrew
Hello AndrewK,
This is true. It is the internal temperature that matters. Just using the battery provides some internal heating that helps replace heat loss with cold ambient temperatures.
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12 hours ago, Susan Huff said:
I say: There are more advantages to lithium batteries, than the elimination of the need for a portable generator.
1. Easier maintenance; blue tooth battery monitoring
2. Faster charging
3. 80% of battery usable in Lithium vs 50% in AGM/flooded; less worry of dangerous level of discharge
4. Longer battery life
5. Increased resale value (only an advantage if you sell)
6. Solar Tax credit - jury is still out on how much of the cost can be claimed as a credit against tax liability
7. Less weight to carry
Running the AC off the batteries is near the bottom of our list of perceived benefits of the Lithium Pro Pkg. 1. We have seldom used our AC in the past 10 years of RVing. 2. We tend to tolerate heat better when we are enjoying the outdoors. 3. I anticipate it will be easier to maintain a comfortable temperature inside the well insulated Oliver.
Hi Susan,
Just FYI, we (Starlight Solar Power Systems) have designed and installed over 3000 RV solar power systems since 2001. Customer always claim the entire amount of parts and labor using the ITC. This includes batteries because a battery is a necessary part of the system.
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16 hours ago, Overland said:
It does seem that the LifeBlue batteries have a narrower operating range than my Battleborns. Their recommended operating range is 24° to 135°. Actually, 24° is the temperature at which their BMS will cut off charging, as measured within the battery. So conceivably, the outside temperature could dip below that, since it would take a while for the batteries themselves to reach that temperature. To my knowledge, Battleborn doesn't have a recommended storage range, but I do know that Victron recommends -49° to 158° for their batteries, and they are generally pretty conservative with their numbers.
Battleborn doesn't require you to discharge their batteries before storage. They do recommend disconnecting any trickle charge (solar).
Hello Overland,
Your statement is incorrect. LiFeBlue Battery has a very broad operating temperature range of -4°F to 140°F. Cell over temperature protection turns on at 149°F. With the LB12200D-LT (sold by OTT) you can charge and discharge within this range. The batteries can withstand -40°F but should not be stored below -4°F.
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16 hours ago, Fritz said:
It is clear that some of you have a very strong electrical background, but I needed some refresher to better understand these lithium battery discussions. So I’m going to try and re-phrase what I’ve learned from this discussion and Oliver. And, cutting to the chase, I’m rethinking the value of the lithium pro package.
Perhaps this summary will help others. Warning: long post.
Electrical current can be described with this formula:
Current = “I” (amps) = Power (watts) / Voltage (V)
By example, the current 11,000-btu A/C draws about 1,100 watts. If plugged in to 120V shore power, the current to run the A/C is 1100W/120V, or about 9.17 amps. If, however, the A/C is run on inverted 12V power, the draw is 1100W/12V, or about 91.7 amps. Thus, an hour’s worth of battery-powered A/C would discharge the batteries by about 92 amp-hours. Actually, the discharge would be a bit greater (about 2 amp-hours), because the inverter uses about 2 amps to do its inversion.
After this hour of cool air, the batteries could be recharged with shore power at 120V, solar gain at 12V, or (at least theoretically) the tow vehicle (at 12V).
Several people have commented that tow vehicle provides very little charge through the standard 7-pin connector, because the wiring is too small. LifeBlue described a TV wiring modification to provide a greater charging current, but others (e.g., Overland) have questioned the ability of newer alternators to supply this current without damage. Absent TV modification, this option is out.
With shore power, the controller is set by Oliver accept a charge current of 100 amps. At this rate, it would take a little less than an hour to replace the 92 amp-hour charge after using the A/C with battery power for an hour.
The battery could be recharged with solar gain, but this would take substantially longer. With an average gain of about 120 amp hours (see Overland’s solar availability chart posted 6/15/20, using May Wyoming/Montana values), it would take almost a full day of charging (~120 amp-hours) to make up for an hour of battery-powered A/C use.
The battery also could be charged with a generator to replace the draw of an hour’s worth of battery-powered cool air, but this, for some, might defeat the purpose. Nontheless, a 1000W generator might replace the 92 amp hours in about an hour (at 100 amps/hr), and a 2,000W generator would do this same job in about 30 minutes. (as an aside, I just checked the Honda 1000W and 2000W generators on Amazon: the 2000W unit is 10 lbs heavier than the 1000W version, slightly quieter than the 1000W unit, and only slightly more expensive.
Other electrical uses are also drawing from the battery. This includes lighting (about 7 amps with everything on), electronics (camera, wifi, cell booster, tank monitor) takes about 5 amps, water heater uses about 5 amps, and both vent fans might pull up to 9.5 amps. The inverter takes about 2 amps when in “invert” mode and about 0.4 amps on standby. A composting toilet fan draws perhaps another 1-2 amps. The furnace draws electricity to run. My point is this: an average solar gain of about 10-15 amps on a moderately sunny day, with the trailer in the sun for perhaps 8 hours, will be just enough (or maybe not quite enough) to make up for regular daily uses. There’s not much solar gain left over to recharge from battery-powered A/C use. Similarly, on a series of cloudy days in (as is common in the Pacific Northwest), or when parked in shade, the solar alone could be insufficient for even basic uses over a period of time. Question: does this reflect your experience?
So now I get it: this is the reason that folks carry generators (which I’ve always avoided). My hope for the lithium pro solar package was that it would reduce the need for a generator, and perhaps provide the occasional 30-60 minutes of A/C during a hot rest area break. But without generator or shore power (or modified TV power), it’s hard to see how the solar system will keep up with even occasional A/C use. It seems that after spending a premium for lithium pro system, the weakest link could be the solar charging capacity (i.e., need more panels). And if a person is going to carry a generator anyway, might not the 2000W inverter and AGMs be sufficient?
Thoughts, anyone?
Excellent Fritz. You make my point well for why I highly recommend installing the TV auxilliary charge circuit. It eliminates the need for a generator.
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18 hours ago, Overland said:
Correct - all lithium batteries need a battery management system, or BMS, which will help keep the batteries from being charged in freezing temperatures, as well as protect them from over current, over charging, fully discharging, etc. It will also monitor the individual cells within the battery to make sure that they maintain the same voltage.
To my knowledge, all of the major players either have the BMS built into their batteries, or sell a BMS to be installed separately. I think it would really only be an issue if someone is buying their batteries directly from China. Hopefully, anyone who goes through that much trouble will have done their homework.
One important note: some of the batteries mentioned in this thread do not have low temperature protection.
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16 hours ago, Fritz said:
Lithium Batteries in Cold Weather
- The LifeBlue batteries require heating when charging at less than 37°F. The only way to charge them at temperatures less than 37°F is with 120 V shore power (or perhaps generator). Shore power is first used to heat the batteries, and then to charge the batteries. The batteries can provide electricity at temperatures less than 37°F, but they won't accept a solar charge.
Hello Fritz,
Statement 1 above is incorrect. With our latest BMS, if the cell temperature drops below about 26°F, the heater circuit will activate whenever you apply charge current. If the current is below 0.05C , charge current will be delivered to the cells. If above 0.05C but less than the minimum required for the heater, the battery will not charge and a 10 minute delay timer will start. When sufficient current is available, the heater will activate. When the release temperature threshold is met, current will be directed to the cells.
The charge source can be anything that make 12 Volts, shore power, alternator, generator or PV solar. You can combine charge sources if needed.
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in Towing an Oliver
Posted
That's a very short run from alternator to house battery. Are you measuring the entire wire length? At 10' and 100A charge current, you are loosing 2.23% through the wire plus connector and isolator losses. That's probably over 0.5 Volts. If your alternator is at 14.0V then the battery end will only be 13.5V.
We recommend designing for 0.2V drop maximum if you want to charge with high current from an alternator. The important part to understand is the lower the voltage drop in he circuit, the higher current that will be delivered to your house battery.