Brightway AGM charging specs.

[2008RN]

I am setting up  two Victron 12/12-30AMP DC-DC chargers in parallel.   I have a 2020 Oli with  Zamp solar charger and  Brightway AGM 6volt batteries in parallel series from the factory. I have look for specs on the Zamp charger, and the AGM for trying to setting up the the Victrons with the proper charging characteristics.

From Docs on the Zamp I  know the following:     Absorption: 14.4V for 4 hours.  Nothing appears to be to be configurable.

The Victron sets  the folowing for AGM batteries. Absorption 14.7V for 6 hours limit. float voltage 13.8.  All values appear to be configurable.

I have not been able to find any charging specs on the AGM brightway batteries.

Any input on setting up the charging characteristics  on the Victron?

 Maybe, I'am over thinking this, but I just want it  setup as correctly as possible.

 

 

 

[taylor.coyote]

 I'm interested in what you learn and your process/cost setting up DC to DC charging. I have spoken with AM Solar located in Springfield, Or about DC to DC charging for my 2019 f250/Oliver.  They seem to be experts in RV solar applications and DC to DC charging. You might want to speak with them. They were very open to share information but required setting up a phone meeting a week or more in advance. 

They quoted in the range of $4,000 to pull 2AWG wire through my truck / trailer to support DC to DC charging. The cost slowed me down and I put DC to DC charging on the back burner for now.  I would appreciate if you would share your set up and installation process.   

[jd1923]

14 hours ago, 2008RN said:

I have not been able to find any charging specs on the AGM brightway batteries.

I just looked at the Brightway website and it's not easy to navigate. I would call their customer service and ask them to send you the spec sheet for your specific battery model. All battery manufacturers have specs sheets with suggested charger configuration. 

On a side note, why two (2) DC-to-DC chargers? Wanting a higher charge rate? Make sure your TV alternator can handle the load of two chargers, let alone one.

That's a lot of money @taylor.coyote! I see parts & labor come to $2000, so $4000 - Yikes! The parts add up to less than $600 total (100 FT 2 AWG cable, one charger, battery terminals (lugs) and misc.). Add another $260 if you really need two chargers.

The cable is $215 plus tax: TEMCo INDUSTRIAL WC0180-50' (25' Blk, 25' Red) 2 Gauge AWG Welding Lead & Car Battery Cable Copper Wire Black + RED | Made in USA - Amazon.com This link comes up as 25 FT of red and black each, but you need at least 40 FT each, I'd buy 50 FT red, 50 FT black 2AWG to be safe. With one charger perhaps 4AWG is good, but I would need to see more specs to make a proper cable gauge decision. When purchasing, make sure you get pure copper welding lead. TEMCo is good and if you find cheaper, it is likely not the right cable. You allow the RV Co to make purchasing decisions and you will get the cheapest product they can source.

The chargers are $240 plus tax: Amazon.com: Victron Energy Orion-Tr Smart 12/12-Volt 30 amp 360-Watt DC-DC Charger Isolated (Bluetooth) : Automotive

"RV shops" are supposed to be experts, but not always true. The wait is often long and they always overcharge. I would figure out your design (good examples to follow on this forum), purchase the components yourself. Then given you will not do the labor yourself, all you really need is a local mechanic. Lots of local "mobile mechanics" that would love to come on your property for this job at a reasonable price!

Priced at $4000, with $1000 in parts and say a shop rate of $110/hour, leaves 27 hours in labor. This job is nowhere near 27 hours and keep in mind, they have profit in the parts and labor. If RV shop had standard flat-rate hours as in the automotive industry, this would be somewhere between 8-12 hours, less than half of the quoted $$$. @taylor.coyote, it's good the "cost slowed me down." I'd say, leave that RV shop and drive away as fast as you can! They're wanting $2000 off the top and another $2000 in parts and labor (with considerable profit already in parts & labor).

[topgun2]

Certainly I'm no expert on this subject - but - 

why are you wanting a DC to DC charger in the first place given that you have AGM batteries?

What am I missing here in that I assume that you are still getting a charge via your alternator in your tow vehicle?

Bill

[jd1923]

2 hours ago, topgun2 said:

...why are you wanting a DC to DC charger in the first place given that you have AGM batteries? What am I missing here in that I assume that you are still getting a charge via your alternator in your tow vehicle? Bill

Thanks Bill, for asking! OTT disconnects the 12AWG Black wire when they install Lithium. They should ignore that Black wire in all the Olivers they build. Why run this wire to the positive bus at all? It has no viable purpose but could cause harm. This low amperage wire could heat up, melt insulation and perhaps create a fire.

Given you drive long between overnights, the DC-to-DC charger at 4-6 hours can near fully charge your batteries (say 98%), and this is the reason. 

I was getting shocked when rewiring a new 7-blade connector on ours, and as soon as I figured out why, after checked the wiring diagram, I went under the streetside bed, disconnected it, taped the open end and dropped it down below, to never be used again! Regardless of the batteries, lead-acid, AGM, or Lithium this connection has no viable purpose. Anybody reading here, who did not opt for Lithium, should disconnect this black wire. I posted this pic in another thread, but it's necessary here again. Notice the black wire hanging.

At best a 12AWG wire could deliver a trickle charge to ANY sizeable RV "house battery" bank. Say you have 450AH of lead-acid, as we do, and you drained the batteries down to 50% overnight. Then get up in the morning and hit the highway. Your LARGE AH STARVED BATTERIES would be asking for way more than that skinny little 12AWG wire can handle (hence the heat/resistance). I'm not a safety kind-of-guy, far from it, as I'd rather do this little task, than say put new batteries in a smoke detector!!! Proper design and prevention vs. detection, is my preference.

I have little interest in a DC-to-DC, because our camping out here is mainly casual-local. There are many of you, from what I've read, that put on 300 miles +/- a day. I prefer when we go away for a 3-4 week trip, to drive 2-3 hours, every 2-3 days or more, drive less and stay more. For those that drive 300 miles in a day, the DC-to-DC charger has real value. In fact, if this is your style, you can skip the solar package and just charge daily while driving!

Two DC chargers? Likely unnecessary. What size AWG cables? Consult an electrical engineer, and keep in mind the design must be right, since you are then asking your TV alternator to work a HD electrical task it was NOT designed for. So many of us want what's best for the Oliver and our travels but do keep the TV in mind!

Thinking of installing one of these, talk to an automotive mechanic. See what you can do to ensure your TV alternator can handle the load. An alternator upgrade may make sense, may even be necessary, and keep your original alternator as a back-up (if ever you should need it, disconnect your DC-to-DC charger until service). 

Most trucks have a HD alternator choice producing about 10% higher amperage throughput. The Dodge Ram 2500 Cummins diesels (and other HD 2500s) were designed with this in mind (plus 2 starter batteries) and have a HD alternator OEM. Generally, this is not so with SUVs and the 1500 class truck. You do not want to charge house batteries while starving the ignition system and ECU of your TV! Your truck could stall while driving. The upside is you could watch television, cook dinner, sleep overnight, while you wait for your TV to be towed in the next morning for repair, resulting in installing a new alternator and perhaps a new starter battery.

[2008RN]

I boon dock, a lot more than I stay in a park with utilities .  So being able to charge the batteries when traveling is nice luxury.  Once I retire we plan being out for at least a couple of months once or twice a year.  It is great staying a 2-3 days in once spot and then move down the road and being able to make a big dent in getting the batteries charged.

I have been planning/researching this upgrade for over a year, and have spent 4 months methodically upgrading the truck and camper. I upgraded my alternator on my F250 Super duty diesel to handle the load. I have updated wiring in the truck; The alternator to one battery with 4/0 wire. The positive wire between batteries was upgraded to 2/0. I also upgrade grounds from battery to engine, frame and body to 2/0 wire.  I ran 2/0 wiring to the Oli.

In the Oli, I put in both Positive and negative buss bars and ran 4/0 wires from the batteries to the buss bars cleaning up the battery compartment and getting all connection in the bay.  Long term I would like to move to lithium batteries.

It sounds like a few of you think I'm crazy doing this. I could never afford to pay someone to do this type of endeavor. Fortunately some people have done this and were successful. I also have to thank Victron technical support for helping pave the way.

@jd1923: I will try to get a hold of the manufacture for the specs on charging.

 

[katanapilot]

Not sure about the experience of others with the Brightway (Chinese made) batteries, but if yours are more than a couple years old and you depend on them for boondocking - you might want to think hard about replacing them sooner rather than later.  Ours failed in about three years with very little use, as we mostly camp with FHU. I had difficulty removing the batteries recently, as they had swollen up and wedged themselves into the battery box. These batteries were not high quality - a concern I expressed to Anita when Oliver made the change from Trojan (in 2020 as I recall). This was an expensive upgrade, clearly not worth the cost.

We just bought three BattleBorn lithiums and will install them soon.  Yes, I know we need to change the converter configuration for the lithium batteries.

[Ronbrink]

16 hours ago, jd1923 said:

This link comes up as 25 FT of red and black each, but you need at least 40 FT each, I'd buy 50 FT red, 50 FT black 2AWG to be safe. With one charger perhaps 4AWG is good,

Good call! I bought 50’ R/50’ B 4AWG for my initial single unit DC-DC 20A, subsequent 40A upgrade, install(s). The length was sufficient for my particular TV and unit install under the rear dinette hatch. Definitely 2AWG with two units.

[jd1923]

11 hours ago, 2008RN said:

... I have been planning/researching this upgrade for over a year, and have spent 4 months methodically upgrading the truck and camper. I upgraded my alternator on my F250 Super duty diesel to handle the load. ...

It sounds like a few of you think I'm crazy doing this. I could never afford to pay someone to do this type of endeavor. ...

@jd1923: I will try to get a hold of the manufacture for the specs on charging.

Nothing crazy here at all. For my part, I was only questioning two 30A chargers, but you've done your research and know what you want. Please post an upgrade thread along your way so we can learn from it.

First time (on this forum) I've read re an alternator upgrade to match, and I commend you for doing this! Even the mighty F250 Super Duty diesel needs an alternator upgrade for two chargers (if not one).

Me too, on the not affording to pay a shop to do this work, though some owners lack the knowledge or physical ability (to crawl under trucks!). I did a 420W Solar, 1800W inverter, 315AH AGM batteries, Bogart Engineering solar charger and battery monitor with Wi-Fi setup for $2,360 total in parts, on a Class-C Bigfoot. Labor at an RV shop would have been how much? Up to $10K? Who knows.

We're only part of this Oliver family for finding an older hull for sale used, in fair condition at a good price. And so far, I've added $5,000 in parts in 7 months, plus 100-200 hours in "sweat equity!"

Edited January 9 by jd1923
Added more content.

[MAX Burner]

7 hours ago, katanapilot said:

Yes, I know we need to change the converter configuration for the lithium batteries.

You'll definitely want to check which type of control board you've got in your current converter/charger.  We had to buy (approx $65) a new control board for ours because it didn't have the "Li micro switch" - you won't hurt your Li's, but the max charge you'll see without the Li-capable board is about 13.6vDC.  After installing the new board - we saw the full 14.4vDC which is indicative of the Li charging profile.  No biggie to replace the board - less than 30 minutes; if you even need it as your C/C may have the optional micro switch for the Li charging profile.

[Ronbrink]

1 hour ago, MAX Burner said:

; if you even need it as your C/C may have the optional micro switch for the Li charging profile.

I checked on this switch, but my 2020 seems to have a different setup. Really posting to ask what is the purpose of the Cerbo GX in your application?

[Geronimo John]

 

17 hours ago, jd1923 said:

I was getting shocked when rewiring a new 7-blade connector on ours, and as soon as I figured out why, after checked the wiring diagram, I went under the streetside bed, disconnected it, taped the open end and dropped it down below, to never be used again!

I chose to remove the fuse that feeds that small wire to the 7-blade.  That way if I choose to use another trailer with brake away switch and battery, I can easily restore the charging current to the emergency battery on their trailer.

14 hours ago, 2008RN said:

I boon dock, a lot more than I stay in a park with utilities .  So being able to charge the batteries when traveling is nice luxury. 

Amen.  I travel not 250 or 300 miles a day, but 400 to 500 a day when I  am on the move.  Having a single 12/12-30 amp is more than sufficient.  In fact, I don't even come close to needing to charge daily when in "GO" mode.  I suggest installing one such unit and verifying your experience is acceptable, then great.  If not, add a second later.

GJ

[2008RN]

 

11 hours ago, Ronbrink said:

Good call! I bought 50’ R/50’ B 4AWG for my initial single unit DC-DC 20A, subsequent 40A upgrade, install(s). The length was sufficient for my particular TV and unit install under the rear dinette hatch. Definitely 2AWG with two units.

On my Oli I used the top of the wheel well under the street side bed.  It was a nice large platform,  I had to move the cable for the back dump valve a little. Main I un-taped the cable and pulled it out from the wall. it was a win-win the cable now has a larger arc and pulls/pushes much easier.

6 hours ago, jd1923 said:

Nothing crazy here at all. For my part, I was only questioning two 30A chargers, but you've done your research and know what you want. Please post an upgrade thread along your way so we can learn from it.

First time (on this forum) I've read re an alternator upgrade to match, and I commend you for doing this! Even the mighty F250 Super Duty diesel needs an alternator upgrade for two chargers (if not one).

We're only part of this Oliver family for finding an older hull for sale used, in fair condition at a good price. And so far, I've added $5,000 in parts in 7 months, plus 100-200 hours in "sweat equity!"

I was disappointed in the mighty F250 alternator. It is suppose to be a 110A alternator. Max amps I could every reach was 75Amps.  That was on a cold morning after the glow plugs had been on for 2 minutes (210 Amp) draw, and a 10 seconds on the starter at 850Amps.  I only tested the new alternator  once, but on a cold startup it jumped up to around 130 Amps, then dropped down to about 85 Amps for a while then started to slowly drop down.

I found my Oli used, it was 9 months old. The nice thing, was If I was going to order it from the factory, it had almost everything I needed.

13 hours ago, katanapilot said:

Not sure about the experience of others with the Brightway (Chinese made) batteries, but if yours are more than a couple years old and you depend on them for boondocking - you might want to think hard about replacing them sooner rather than later.  Ours failed in about three years with very little use, as we mostly camp with FHU. I had difficulty removing the batteries recently, as they had swollen up and wedged themselves into the battery box. These batteries were not high quality - a concern I expressed to Anita when Oliver made the change from Trojan (in 2020 as I recall). This was an expensive upgrade, clearly not worth the cost.

We just bought three BattleBorn lithiums and will install them soon.  Yes, I know we need to change the converter configuration for the lithium batteries.

Thanks for the heads up, Ours are just over 3 years old.  knock on wood, they seem to all be working fine right now and do not seem to have any swelling yet.  I have looked at some batteries, but haven't made my mind up yet, I had figured that I still had time. The Lithionics batteries seem really nice, the Cadillac of batteries. Boy are they expensive, As of about 6 months ago, I was reading about failures with battle born.

[mossemi]

On 1/7/2024 at 11:22 PM, 2008RN said:

I am setting up  two Victron 12/12-30AMP DC-DC chargers in parallel. 

I just saw this YouTube video about the new Victron 50A DC-DC  charger by Nate and Steph of EXPLORIST life - DIY Campers.  It might be worth the wait!

Mossey

https://youtu.be/ByhIxhA-x8M?si=54SM0UL8sDgV3KJm

[2008RN]

 

3 hours ago, mossemi said:

I just saw this YouTube video about the new Victron 50A DC-DC  charger by Nate and Steph of EXPLORIST life - DIY Campers.  It might be worth the wait!

Mossey

https://youtu.be/ByhIxhA-x8M?si=54SM0UL8sDgV3KJm

Very Cool,  Unfortunately I'm a day late and a dollar short. I had everything built a week ago besides the chargers added. I purchased the chargers last Friday, installed them Saturday and tested today.  It would have simplified my whole design. Smaller wires, no fans, and simplified and smaller foot print.

Here is what my install looked like. I epoxied a 1/2" marine white board to the  wheel well. Attached everything to a piece of 3/4" marine board and then attached the 3/4" board to the 1/2" board.  Space was definitely at a premium.  My test showed each charger at 38Amps before warm up. After one hour one charger was  34Amps at 96degrees F, and the orther 32.5 amps @ 100degrees F.  Victron rates the 12-12/30 at 104 degrees F. Anything over 104F the Amps decrease below 30 F. I have heard as low as 25 degrees F

each pair of fans positive lines are connected to the Optifuse breaker. So I can turn off either of the chargers and associated fans from the other charger.

 

This is the  1/2 base.

 

[mossemi]

18 hours ago, 2008RN said:

Unfortunately I'm a day late and a dollar short.

I am familiar with that policy, so we’ll leave yesterday behind.  Your DC - DC layout looks like it’s well thought out and executed.  Keep us posted on your real world experiences and thank you for the 'show and tell'.

Mossey

[jd1923]

Wow @2008RN this is awesome! You have a very well thought out design, hardware laid out nicely and personally I cannot wait to see your DC-to-DC gear mounted, working and to hear of your results!

The cooling fans reminded me of a thought I've had before. Perhaps @Ronbrink can chime in too, who worked his DC charger installation --

Is there a difference in where you locate the charger(s)? Should the charger be closer to the alternator or closer to the batteries, does it matter? Of course, when you install an inverter, it must be as close to the batteries as possible! Does position matter in the DC-to-DC design? (closer to starter or house batteries?)  

My first thought on this installation would be to install the charger up front near the starter batteries. There's generally room in pickup trucks just in front/under the battery. Victron hardware is design for boating, should be mostly waterproof. If mounted up front it would cool while towing, no fans required. This way, there would be little concern if this hardware would cause harm to the $$$ Oliver (less overall risk). 

Let me know what you think. You have researched this and I'm learning re your application. Thanks

 

 

 

[Ronbrink]

8 hours ago, jd1923 said:

Should the charger be closer to the alternator or closer to the batteries, does it matter?

The DC-DC should be mounted as close as possible to the batteries, at a location where there is sufficient room for proper ventilation. If proper ventilation is an issue due to the mounting location or size of the unit(s), then fans are often used. Although 2008RN made good use of valuable real estate at the rear wheel well below the street side bed, there is not much clearance between it and the hatch lid when closed. Knowing this, he took extra precaution in adding the fans to provide adequate ventilation to his superbly installed dual-unit setup. I my installation, 1/2” plywood was adhered to the fiberglass within the interior rear dinette seat hatch, just below the battery box enclosure (reflective insulation at upper righthand corner of pic). I have not experienced a heat issue with use of this 40A unit, even when traveling last summer to West Texas with daytime temps in excess of 110°. 

[MAX Burner]

On 1/9/2024 at 12:08 PM, Ronbrink said:

Really posting to ask what is the purpose of the Cerbo GX in your application?

For our application, the Victron Cerbo unit receives the input from each of our other Victron devices (MPPT solar charger, portable solar modules, SmartShunt, DC-DC charger, 3kw Inverter/charger (TBD), etc.) and depicts the flow of AC and DC current at that moment.  It tracks a historical trend of power usage.  Displays are provided on the optional 7" touch-screen.  It gives us a snapshot view using a "flow-chart" graphic of exactly what's happening electrically at a given moment.  We fitted the touch-screen into the space where the Zamp PWM solar charge controller used to be, FYI.

This screen selection is actually animated a bit.  It displays moving "dots" between the power sources and the usage points in the direction the current is flowing.  Pretty cool and easy to get your head around what's happening at the moment.

Cheers!

Edited January 12 by MAX Burner
Added a photo of the unit...

[Ronbrink]

20 minutes ago, MAX Burner said:

For our application, the Victron Cerbo unit receives the input from each of our other Victron devices (MPPT solar charger, portable solar modules, SmartShunt, DC-DC charger, 3kw Inverter/charger (TBD), etc.) and depicts the flow of AC and DC current at that moment.  It tracks a historical trend of power usage.  Displays are provided on the optional 7" touch-screen.  It gives us a snapshot view using a "flow-chart" graphic of exactly what's happening electrically at a given moment.  We fitted the touch-screen into the space where the Zamp PWM solar charge controller used to be, FYI.

Wow, sounds like a very sophisticated setup! My Son has suggested I incorporate one of the Cerbo models to remedy a charging issue, and was wondering how else an install could be of benefit to the Oliver. Thanks for your reply, much appreciated!

[Jps190]

On 1/8/2024 at 6:23 AM, taylor.coyote said:

 

They quoted in the range of $4,000 to pull 2AWG wire through my truck / trailer to support DC to DC charging.   

********!!!! Is the wire made of gold? 😂😂

[ScubaRx]

6 minutes ago, Jps190 said:

********!!!! Is the wire made of gold? 😂😂

30 feet of 2awg red + 30 feet of 2AWG black will cost nearly $250. 60 feet of each would be about $470. The wire is not cheap, but I suspect that it is the labor that is tearing you a new one. Is there any reason you wouldn't want to do it yourself. I am about to do the same thing and I was figuring well under $1000 for materials. I can't afford the labor fee I would charge. The job is not technical or particularly difficult, but it is time consuming to do it correctly and there's not a lot of folks I'd trust to do this job like I would want it done.

[Jps190]

38 minutes ago, ScubaRx said:

 The job is not technical or particularly difficult, but it is time consuming to do it correctly and there's not a lot of folks I'd trust to do this job like I would want it done.

That's my problem with all projects. 😆

[2008RN]

3 hours ago, ScubaRx said:

30 feet of 2awg red + 30 feet of 2AWG black will cost nearly $250. 60 feet of each would be about $470. The wire is not cheap, but I suspect that it is the labor that is tearing you a new one. Is there any reason you wouldn't want to do it yourself. I am about to do the same thing and I was figuring well under $1000 for materials. I can't afford the labor fee I would charge. The job is not technical or particularly difficult, but it is time consuming to do it correctly and there's not a lot of folks I'd trust to do this job like I would want it done.

 

My project was little more expensive.  with Victron dual chargers, wire, alternator, shunt and miscellaneous like Anderson connecters, buss bars, breakers, fuses, wire sheathing, battery shut off, and lugs, heat shrink, crimper...    I think my total cost approximated $1900.  I pulled the fuel tank to properly run the wire in the frame rail something RV solar installer probably would not have done.  I Ran wire sheathing on all cable except the actual board with the chargers. Anything that had any rub potential was covered.  I ran a jumper cable between the truck and Oliver so that If I didn't need to charge while traveling I just wouldn't hook it up. Also makes it clean when parking. The  Official Anderson connectors are not cheap, (knock offs are available).

My cost would have been a lot less if I knew ahead of time the new Victron 50Amp charger was coming out. I could have lived with the 50Amp efficient DC-DC charger.  I planned on a max of 100 amps input from the truck to run the amps, with my testing I maxed out at 88-89 Amps. With the new 50Amp charger I would bet 60Amp max input would be need, and I would wire for 70 Amps.  That would have cut down on all cost of virtually every item and probably cut cost by about $500. 

Just an FYI I bought 47' (x2) of wire to run from the front of my F250 extended cab with 8' bed to just aft of the of the Oli battery bank. I had about 2' extra of each red, and black wire.   Also as a side note, I bought wire from battery cables usa. I got the extreme battery cable. Very fine wire like welding cable. double sheathing (hard intercore and flexible outercore. Also the inside Copper wire OD was larger than spec.  I like the extra safety margin with slightly lower Ohms and more carrying capacity. I only thing is that on 1/0 to 4/0 wires it was almost a press fit( it takes force to put the wire in the lug. I just couldn't strip the sheathing back and put the lug on.  I had to use a 2 step process. 

[MAX Burner]

14 hours ago, ScubaRx said:

The job is not technical or particularly difficult, but it is time consuming to do it correctly and there's not a lot of folks I'd trust to do this job like I would want it done.

Concur 100%.  That's why we did it ourselves - it took less than a half-day to configure the Tundra with wires, fuse, and Anderson plug/mount from engine compartment to hitch area.  Took about the same time (maybe a bit less) for the OTT side of the equation.  We used clam hull penetration hardware to introduce the cables into the area below the bathroom sink, underneath and in front of the head, under the forward dinette, to the aft dinette area where we mounted the DC/DC charger.

Note:  In bulk charge mode this particular charger kicks off some heat.  We've been leaving the aft seat hatch off while towing to better circulate air around the cooling fins of the charger.  There's a ton of YouTube videos of how some RV fabricators attach cooling fans.  As described and photographed earlier, having two of these bad boys in close proximity will create some serious heat and auxiliary fans would definitely be helpful.

As of this post, currently boondocking just south of Elephant Butte Lake SP waiting for the temps to rise above freezing before heading off to "The Q" - planning for a mid-afternoon arrival in the Sonoran Desert where its been above freezing temps for a few weeks now.  

FYI:  OATs here last night dropped to 20F.  Starting a 10pm last night with 96% SOC, ran the furnace and water heater all night and woke up at 5am to a 78% SOC.  Not too bad....  I'm expecting to have 100% SOC by the time we hit Benson, AZ, with the DC/DC charger cranking +/-30A/14.4vDC into the BBs.

Cheers!