[Jordan Y]

I have enough space behind the drivers seat and my partition to fit my house batteries (two cardboard templates at the moment) and I’m wondering if there are any downsides to this idea.

The batteries I’m getting are the self heating lithium batteries from renogy as I’ll primarily be on the west coast of Canada where winter temps can fall below freezing: 100Ah 12 Volt Smart Lithium Iron Phosphate Battery W/ Self-Heating Function

The batteries would be secured and the rest of the power station would be about 3 feet to the rear. I plan to connect to the alternator as well as solar. I also wonder if I could keep more components in the cab area mounted to the wall of the partition behind the seat.

I don’t have my whole system worked out yet so I’d love to hear pros and cons to this idea or if there’s anything else I should consider. It would be great to utilize the space.Thanks!

 

[andyl]

Looks great!

An alternative to consider: if you measure a bit, you may find that your batteries fit under your passenger seat.

 

[carpen7]

2 things i see:
1) The batteries will be in the unheated portion of your build, and will have to use the self heating function, so they won't last as long.

2) with the rest of the components in the rear you'll need pretty big ($$) wires to feed the power to them.

 

[EricB]

If you go ahead with the plan, run your seat all the way back before you place the batteries. I (stupidly) built cabinets behind the driver's seat without thinking of my general SHORT stature. Now, every time I have someone else work on the van or take it in for inspection, I have to warn them not to run the seat back or it'll break the power seat mechanism loose. Duh!

 

[njvagabond]

1) The batteries will be in the unheated portion of your build, and will have to use the self heating function, so they won't last as long.

I am curious about the the self heating reducing battery life? Is that because the temp of battery will not be uniform?
Or is there something in general with regard to the LiFPO4 chemistry at lower temps?

2) with the rest of the components in the rear you'll need pretty big ($$) wires to feed the power to them.

VS. big wires from the vehicle to the batteries in the back? Might be the same or similar. I suppose if reducing wire, then the placement would depend on charge rate vs discharge rate. Now if biggest discharge rate is an an inverter, then if inverter is also upfront in with the batteries, the long runs will be smaller ac wiring. If it's in the cold cab, maybe better for the inverter.

I suppose it might be possible to modified the partition toto box them (w/insulation) in so they were in the heated space.

 

[njvagabond]

If you go ahead with the plan, run your seat all the way back before you place the batteries. I (stupidly) built cabinets behind the driver's seat without thinking of my general SHORT stature. Now, every time I have someone else work on the van or take it in for inspection, I have to warn them not to run the seat back or it'll break the power seat mechanism loose. Duh!

Is that because the top of the seat hits the partition and acts like a lever arm. Maybe you could drill a hole in the bottom of the seat rail (just like it's attached to the base ... so strength should not be an issue) and then put a bolt/w spacer on it to act like a stop. SHORT people rock!

 

[AzB]

I am curious about the the self heating reducing battery life? Is that because the temp of battery will not be uniform?
Or is there something in general with regard to the LiFPO4 chemistry at lower temps

Its because the batteries use their own power for heating. Thereby running the batteries down.

 

[andyl]

Its because the batteries use their own power for heating

Some heated batteries activate the heating element only when the battery is being charged. In this situation, it seems to me that the battery may charge more slowly, but battery life should be unaffected.

Agree?

 

[Jordan Y]

I am curious about the the self heating reducing battery life? Is that because the temp of battery will not be uniform?
Or is there something in general with regard to the LiFPO4 chemistry at lower temps?

VS. big wires from the vehicle to the batteries in the back? Might be the same or similar. I suppose if reducing wire, then the placement would depend on charge rate vs discharge rate. Now if biggest discharge rate is an an inverter, then if inverter is also upfront in with the batteries, the long runs will be smaller ac wiring. If it's in the cold cab, maybe better for the inverter.

I suppose it might be possible to modified the partition toto box them (w/insulation) in so they were in the heated space.

maybe I could create an insulated battery box that is vented to the cargo area to allow the warmer air to reach it and prevent the self heating function from kicking in.
Can you elaborate on what you meant when you said the cold temps might be better for the inverter?

 

[njvagabond]

Its because the batteries use their own power for heating. Thereby running the batteries down.

Thanks. So

If you do, please stay on the forum. We really could use more cheerful/positive/optimistic folks like you around here.

I guess then the question is how significant a difference is "as long". Of course the heater is also a potential failure point.

 

[njvagabond]

Can you elaborate on what you meant when you said the cold temps might be better for the inverter?

Fans won't run (as much?) or invertern is less likely to shut down (or de-rate?) for over temp. In general keeping electronics cool is good for longevity of components. But, I also would not sweat it. As long as the inverter is installed with sufficient clearances and airflow all is good. Most manuals have mounting specs that are good to follow.

Keeping the batteries in the heated space seems like it would be a good idea, but not a deal breaker .... assuming that the BMS on a heated battery does not solely rely on the heaters to prevent low temp charging, but has also has a disconnect in case the heater fails or can't keep up with ambient. It would be a good idea to check the battery spec out for that.

 

[harryn]

Some heated batteries activate the heating element only when the battery is being charged. In this situation, it seems to me that the battery may charge more slowly, but battery life should be unaffected.

Agree?

Possibly. If I am reading their literature correctly, those would use the charger power to first warm up the batteries to operating temperature, then begin charging.

I could see this as very useful if the batteries are at 25 F and just need to warm up to 35 F to charge.

If the batteries are at 0 F and need to warm up to 35 F to charge, that is going to take a while. (37 Kg of thermal mass )

I see real value in the idea. If I lived somewhere that is routinely below 30 F and wanted to use LiFe batteries, I would be tempted to just keep the van at 40 F using a heater of some kind - all of the time.

Right now my own vehicle uses AGMs but > 70% of my customers want LiFe, even if they plan to use the van in snow areas.

 

[GROOVY2]

I installed 100ah battery under drivers seat- 2015 -
battery is 4 raw cells no battery case -
it is tight fit - doubt if battery in a case will fit -
solar controller is mounted on rear of seat base

one battery in a case should fit under Passenger seat
maybe 2 could fit if laid battery on side -
seat can be Raised some on spacers if needed -

I made swivel for passenger seat and made so seat
swings Open for storage in seat base -
works well -

 

[harryn]

I would not count on renogy batteries to keep my van warm if you are planning to use them where it really matters.

 

[Jordan Y]

I would not count on renogy batteries to keep my van warm if you are planning to use them where it really matters.

What would you recommend?

 

[andyl]

I made swivel for passenger seat and made so seat swings Open for storage in seat base

Can you post photos?

 

[andyl]

If I lived somewhere that is routinely below 30 F and wanted to use LiFe batteries, I would be tempted to just keep the van at 40 F using a heater of some kind - all of the time.

I have my heated battery in an insulated box under the van. Plan to plug into shorepower 24/7 in cold temps. This winter is going to be the first test, should work in theory, we will see.

 

[Jordan Y]

I have my heated battery in an insulated box under the van. Plan to plug into shorepower 24/7 in cold temps. This winter is going to be the first test, should work in theory, we will see.

What brand did you go with?

 

[andyl]

What brand did you go with?

I'm using a 300ah battery from LithiumHub.

 

[harryn]

What would you recommend?

Either battle born or consider Andyl's suggestion for LiFe.

For AGMs I use Lifeline GPL-27s