Trail Blazer III
What is best auxillary battery to use in cold weather region and with a redarc BCDC1225D charger/isolator? Want a 100AH battery that will fit on auxillary battery tray in SUV (tray size 11"x10" ) Thx.
Aux battery
- Thread starter Kenny
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You are best to go with an Aggregated Glass Mat (AGM) battery. They are designed to work in the heat of an engine bay and can cope with cold without having heating elements (as required for lithium batteries).
AGM batteries cannot be fully discharged without shortening their lifespan so if you can fit a battery with a higher AH rating into the space you are best to do that.
AGM batteries cannot be fully discharged without shortening their lifespan so if you can fit a battery with a higher AH rating into the space you are best to do that.
ADK Kenny
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Typical 100ah battery won’t fit. I presently have the optima yellow top 55ah. Just looking for something larger but, yes, worried about cold weather charging with a lithium. Thx.
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Here is a chart to common car battery sizes. As you can see 24, 34, 35 should fit and there are AGMs within those sizes.
But like others mentioned AGM will never give you the full rated capacity. You should try to keep it 70% charged. Discharging below 50% will rapidly reduce battery life.
But like others mentioned AGM will never give you the full rated capacity. You should try to keep it 70% charged. Discharging below 50% will rapidly reduce battery life.
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How cold are you talking? There are LiFePo4 batteries that will charge down to -4F now. LiTime comes to mind. They also have self-heating options. I would think your RedArc would keep you from changing a cold battery. Also, if you need to charge it on a really cold day/night, since it will be in the engine compartment you will be able to heat it up by running the engine.
ADK Kenny
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I do live in upstate Ny Adirondack state park and it can have its good winter temps. Is Litime compatible with a Redarc BCDC 12/25D?
I've used an Odyssey 34-PC1500T AGM, with my Redarc BCDC1240D without any issues here in west central Wisconsin. I leave it at the airport outside for 6-7- days at a time, in sub-zero weather. I went with the AGM as it can withstand engine bay heat, and you can use it to jumpstart the starter battery, unlike the deep cycle. I believe Redarc has a recommendation not to mount Lithiums in the engine.
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I think most lithium batteries are compatible with RedArc BCDC chargers. If you regularly see temps below 0 degrees F, especially when camping/overlanding, I look at the LiTime batteries with an internal heater. Or any higher quality heated lithium battery.
Kenny, I do not believe KS is correct about lithium and LiTime going to -4f for charging. That number is the limit for DISCHARGING from all the batteries I have seen.
@KS_Explorer , can you provide a link to the spec sheets for LiTime showing a CHARGE capability to -4f? I don't think you are correct, though I wish you were... I don't want bad advice causing OP to buy the wrong battery for cold weather though...
Here is the temp spec sheet for the first 15 LiTime batteries I looked at:
