HOW TO: Lithium Battery Powered Vent System

[Fritz]

The Lithionics batteries come with a heating pad underneath the batteries.  There is a switch in the battery compartment that turns the heating pad on or off.  When turned on, the heating pad comes on when the temperature falls to 35°F. It goes off when the ambient temperature reaches 45°F. This is only necessary to charge the battery, and if there is a charging source available (i.e., shore power, solar, or generator). The batteries do not need a heating pad to discharge (e.g., turn on lights, etc.), even when the temperature is below 35°F.  

 

 

[Fritz]

1 hour ago, Overland said:

Will probably set the fan to come on at 40 degrees and go off at 50.

Another reason for installing a fan would be for summertime heat reduction.  I have found that static temperatures in the batteries to reach 95°F when the outdoor ambient temperatures are slightly over 100°F.  A fast charge to the batteries (100 -150 amps), which I have only done a cooler temperatures, can add 25°. Although the Lithionics batteries can handle up to about 130°F, I would be cautious about a fast charge during the summer (such as after using the air conditioner on battery) without being able to cool the batteries. For that matter, just using the air conditioner with battery power heats up the batteries -- another reason to install a cooling fan. 

Some have insulated the battery box door to keep the batteries from getting too cold. This helps, but absent internal conditioning, the vents should remain open (IMHO) during the summer for cooling.

[Fritz]

15 minutes ago, Fritz said:

The Lithionics batteries come with a heating pad underneath the batteries.  There is a switch in the battery compartment that turns the heating pad on or off.  When turned on, the heating pad comes on when the temperature falls to 35°F. It goes off when the ambient temperature reaches 45°F. This is only necessary to charge the battery, and if there is a charging source available (i.e., shore power, solar, or generator). The batteries do not need a heating pad to discharge (e.g., turn on lights, etc.), even when the temperature is below 35°F.  

I might add that if the heating pad is turned on when there is no other source of power (or no incoming charge from solar in excess of what the heating pad draws), the heating pad may draw down the batteries unnecessarily.  

[NCeagle]

6 hours ago, Fritz said:

It appears that the programmable thermostat speed controller that you used (this one, perhaps: https://www.amazon.com/TerraBloom-Programmable-Thermostat-Controller-Temperature/dp/B083W2MRK6/ref=pd_day0fbt_img_2/146-3356731-9507947?pd_rd_w=Q7AR3&pf_rd_p=bcb8482a-3db5-4b0b-9f15-b86e24acdb00&pf_rd_r=XVV5SHAE2FP5518SGFZW&pd_rd_r=e2e72b65-4f68-4988-9560-bae75e92c00e&pd_rd_wg=FyVXm&pd_rd_i=B083W2MRK6&psc=1) will handle up to 4 fans.  I'm curious if there is a reason that you used two controllers for your installation (one for the basement and one for the battery compartment)?

Hey Fritz, I used 2 different controllers because they are two different brands of fans.  The brand that I had already installed for my basement bilge fan had a 4" diameter fan, but it wouldn't fit in the space under the bed (on top of the wheel well), so I ended up getting the other brand of smart fan that fit very snugly in that space.  Had I started with the battery compartment first, I likely would have gotten the 6" diameter version of the one I ended up using under the bed.

[Overland]

4 hours ago, Fritz said:

Another reason for installing a fan would be for summertime heat reduction.  I have found that static temperatures in the batteries to reach 95°F when the outdoor ambient temperatures are slightly over 100°F.  A fast charge to the batteries (100 -150 amps), which I have only done a cooler temperatures, can add 25°. Although the Lithionics batteries can handle up to about 130°F, I would be cautious about a fast charge during the summer (such as after using the air conditioner on battery) without being able to cool the batteries. For that matter, just using the air conditioner with battery power heats up the batteries -- another reason to install a cooling fan. 

Some have insulated the battery box door to keep the batteries from getting too cold. This helps, but absent internal conditioning, the vents should remain open (IMHO) during the summer for cooling.

I'll insulate the door at the same time, too.  The thermostat description says that it will do both a heat and cool mode, but doesn't give more info than that.  I suspect that I'll have to do some guesswork to find out if that's something I'd have to manually switch, or if I can set it so that the thermostat will kick on automatically either above or below a set range.  I suspect it will be something I'd have to switch over.  That's not a priority for me since the trailer is in storage in the shade during summer.  

[Rivernerd]

On 12/29/2021 at 9:39 AM, Fritz said:

The Lithionics batteries come with a heating pad underneath the batteries.  There is a switch in the battery compartment that turns the heating pad on or off.  When turned on, the heating pad comes on when the temperature falls to 35°F. It goes off when the ambient temperature reaches 45°F. This is only necessary to charge the battery, and if there is a charging source available (i.e., shore power, solar, or generator).

Jason Essary yesterday posted an updated Rev. 7 Lithionics Storage Procedure.  It advises that there is no need to remove the larger 315Ah battery (that comes with the Lithium Platinum Package) from the trailer for winter storage, because it has an internal heater.  But, the Rev. 7 storage procedure for the smaller, 130Ah Lithionics batteries, that come with the Lithium Pro Package, still recommends removing the batteries from the trailer, storing them in a temperature-controlled environment and following the periodic charge/discharge procedure for winter storage.  I infer this is because, unlike the 315Ah, the 130Ah battery does not have an internal heater.

So, do the Lithionics 130Ah batteries installed by Oliver with the Lithium Pro Package still "come with a heating pad underneath the batteries" that is switched in the battery compartment?  If so, as long as the trailer is connected to shore power over the winter (to avoid depleting the batteries when powering the DC heating pad), wouldn't that external heating pad thermally protect those 130Ah batteries, and obviate the need to remove them, store them in a temperature-controlled environment and follow the charge/discharge protocol specified in the new Rev. 7 Lithionics Storage Procedure?

I ask because my wife and I have an Elite II on order with the Lithium Pro Package, and we live in the central Idaho mountains with harsh winters.  The shed where we will store the Oliver has a 30A receptacle with which I can provide shore power all winter.  I would like to avoid the annual removal/storage/charge/discharge maintenance procedure if I can.

 

[Geronimo John]

On 12/28/2021 at 8:07 AM, NCeagle said:

I chose to use a forced air closed system to moderate the battery compartment temperatures

I always enjoy studying  JD's craftsmanship and beautifully executed designs.  Sadly I don't have the shop, tools, skills or time to reproduce many of his works of art.  I also am a Ollie Mod Minimalist (OMM).  So your approach to the battery box (BB) heat/cool is very eloquent in my eyes.  Well done.  It solves both heating and cooling of the battery box.  

For those owners that are OMM's and are only interested in BB cooling, I have hijacked elements of both your and John D's designs.  Then applied my OMM approach to keep it effective, but simple to execute at at a greatly reduced cost.  To be clear, the purpose of this approach is only for BB cooling in extreme heat.  Here is a GJ OMM concept:      

• Install bathroom 4" air return portal as described in other posts.   This and other leakage points will allow cabin "free air" to easily enter forward street side basement.    
• Leave OTT BB exterior vents as is.  But, add reflex insulation around them to reduce solar heating yet allow the vents to function as designed. 
• Add a single air penetration into the battery box.  Recommend this be as close to the cabin side low in the box as possible. Penetration size varies depending on your 12V Box Fan dimensions.  
• Mount inexpensive single speed uber quiet 4" box fan (See JD's suggested fan in post above, or borrow one from an old computer.) Consider using a rubber gasket for sealing and vibration absorption.    
• Install Thermal switch (See below) mounted high in the BB.
• Install On/Off Auto switch and of course a fuse where it is convenient, but not obtrusive.  

Cost:  Peanuts.

Operation:  Switch "ON" or "AUTO".  When thermal switch exceeds 104 degrees F (40 degrees C), the fan comes on and cooler cabin air from the forward street-side basement will be pushed into the BB and out it's existing vents.  Added advantage is it will also help cool the bathroom and basement. 

Recommend executing the above first.  See how it works for your system.  However some will want to depart from the OMM approach to get even more BB cooling, you could always consider adding the following elements:

• If your street side foreword basement is rather hot, you may want to add duct from the cabin to fan as NCeagle used.
• Maybe add deflection louvers on the fan discharge (in the battery box) to better distribute the air into the BB . 
• Maybe add a baffle on the battery box door from the top vents up to the top of the hatch to better pull hot air out from closer to the top of the BB.  
• Add a removeable shade awning for the BB exterior area. 

But for this OMM, I would just go the simple, inexpensive and less visible approach.  

GJ