Lithium Battery

Short-Bed-Dually

Active Member
I have a REGO 12V 400Ah Cold Weather LiFePO4 Battery that I was thinking about possibly mounting in the upper basement of my 2017 Bighorn 3575EL. This would put it a short distance from the converter. Has anyone mounted a lithium battery in this area?
 

david-steph2018

Well-known member
2018 Road Warrior 427, toy hauler.
The original batteries were up front, but when we went to a solar system, had to relocate to side. Just not enough room where the old setup was located.
 

LBR

Well-known member
On our 2017 CY I first wanted to mount the 400AH Lithiums under the bed to make room for all the solar components in the electrical compartment. Two problems were the longer cables and the bed doesn't lift....so I nixed that idea totally and installed them in the factory spot. I could still add one more 200AH battery next to them, but it turned out that we didn't need the increased capacity for the amount of solar I put up.

I did get all of the extra add-ons in that compartment by adding a piece of plywood on the separating wall of the generator compartment...all discos, 3K inverter, fuses, and auxiliary positive/negative multi-hookups, etc.

The only item that wouldn't comfortably fit in that bay is the solar charger....I put it on the pass thru compartment wall up high and out of the way for a short wire run to my +/- attachment points. Also cut a hole thru the compartment next to the charger for a 24/7 running of a 5" computer fan to evacuate the charger's heat produced from it's heat-sink when batteries get to 100% on those hot days.

It all fitt and I can still get my head into the "electrical room" to work on everything..
 

taskswap

Well-known member
In addition to space considerations, don't forget cabling. Electrical devices don't "use" volts, they "use" watts (power). P+E*I which is why 120V at 10A is 1200W and 12V at 100A is also 1200W.

Flipping that around that means if you need to get 1200W out of a system (typical microwave) you'd need 100A at 12VDC to do what 10A at 120VAC will do. Carrying 100A requires quite a stout cable over any distance, and this is one reason AC "won" the "power wars" 100+ years ago. It's also why inverters are almost always located in the same bay as the battery bank and why it's so rare to see battery banks split up into separate locations - the cabling that would be required would make it not as cost-effective in many cases.

Anyway, the reason I'm rambling about this is that I suspect without significant rewiring, it's rarely practical to relocate batteries from where they were originally meant to be placed unless you have no other option. In most coaches the main fuse panel and inverter are both "relatively close" to the battery bank - not necessarily inches, but a few feet in most cases. If you wanted to move them e.g. to the rear or vice versa you might need to upgrade your cabling to carry the loads over that longer distance.
 

david-steph2018

Well-known member
On our 2017 CY I first wanted to mount the 400AH Lithiums under the bed to make room for all the solar components in the electrical compartment. Two problems were the longer cables and the bed doesn't lift....so I nixed that idea totally and installed them in the factory spot. I could still add one more 200AH battery next to them, but it turned out that we didn't need the increased capacity for the amount of solar I put up.

I did get all of the extra add-ons in that compartment by adding a piece of plywood on the separating wall of the generator compartment...all discos, 3K inverter, fuses, and auxiliary positive/negative multi-hookups, etc.

The only item that wouldn't comfortably fit in that bay is the solar charger....I put it on the pass thru compartment wall up high and out of the way for a short wire run to my +/- attachment points. Also cut a hole thru the compartment next to the charger for a 24/7 running of a 5" computer fan to evacuate the charger's heat produced from it's heat-sink when batteries get to 100% on those hot days.

It all fitt and I can still get my head into the "electrical room" to work on everything..
When I need to work on the transfer switch, water pump, I need to lay on top of the batteries to access things behind the wall.
 

Short-Bed-Dually

Active Member
In addition to space considerations, don't forget cabling. Electrical devices don't "use" volts, they "use" watts (power). P+E*I which is why 120V at 10A is 1200W and 12V at 100A is also 1200W.

Flipping that around that means if you need to get 1200W out of a system (typical microwave) you'd need 100A at 12VDC to do what 10A at 120VAC will do. Carrying 100A requires quite a stout cable over any distance, and this is one reason AC "won" the "power wars" 100+ years ago. It's also why inverters are almost always located in the same bay as the battery bank and why it's so rare to see battery banks split up into separate locations - the cabling that would be required would make it not as cost-effective in many cases.

Anyway, the reason I'm rambling about this is that I suspect without significant rewiring, it's rarely practical to relocate batteries from where they were originally meant to be placed unless you have no other option. In most coaches the main fuse panel and inverter are both "relatively close" to the battery bank - not necessarily inches, but a few feet in most cases. If you wanted to move them e.g. to the rear or vice versa you might need to upgrade your cabling to carry the loads over that longer distance.
Good point. I installed a 3000W inverter on the front wall of the pass through basement so the battery cables are about 3 to 4 feet long. I am planning to replace the 6 golf cart batteries in the front basement with the 400Ah LiFePo4 battery. Moving to the rear upper basement is definitely making more work for myself. I thought I read somewhere that mounting the converter closer to a lithium battery would be better. Of course it would be easier to move the converter.
 
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