Battery Suggestions

[Jafo]

Over the last 9 years, I have gone through several different sets of batteries, from flooded, gel and AGM in my off-grid cabin in the Adirondacks. I have received a bunch of help in this forum over the years (thanks btw!). The biggest issue I had to overcome was the fact that it can get down to -35 sometimes in the winter when I am not there (have to snowshoe to it). It really kicked the crap out of a couple banks until I learned to top the batteries off with the generator before I would leave after a weekend hiking in there.

I normally only get up there every other weekend during the summer and the two 100Ah Mighty Max batteries in series have worked fine enough for my typical usage, though not as well in the winter. They are cheap but fine batteries for that kind of usage.

This year I plan on spending significantly more time there and also upping my usage a bit. I will be installing Star Link (coming this week) which can be a bit of an energy hog and my young daughter will be spending time there too with her myriad of devices (Ipad, TV, etc..). All of this tells me it is time to beef up the battery bank a bit.

The controller I have has worked well since I got it.

Now it is time I think to get perhaps a 200AH battery bank (two in series) and I have been looking over my options. My how things have changed over the last 5 years or so! I see lots of LiPo batteries out there now, but as far as I can tell, this could be a problem when leaving them in the cold, but finding absolute data on this has not been easy.

My gut tells me to stick to an AGM bank, and I am consider either this one by Mighty Max or this one by Renogy.

So my questions are:

Should I give LiPos a look or am I right that these are not a good fit when you cannot control the temperatures all year long?

Anything wrong with these batteries I am looking at?

Any battery you might recommend?

Thanks as always!

[littleharbor2]

FLA and AGM batteries should be fine in those low temps if left FULLY charged. It would be important to remove all loads from them while you are away, If you have a charge controller connected you should disconnect it as it will draw power . I'm assuming you have solar and get snow obscuring their power production.
People in cold climates typically get longer life from their batteries than those in warmer/hot climates

[GTAZ]

I would agree with littleharbor2. I wouldn't leave LiFePo4's I sub freezing temps.
If your FLA and AGMs are handling the temp well, I'd stick with them. And if your current batteries and generator are still good, you can just add some capacity. Problem solved.

The one other alternative (which is waaay too pricey) is Edison Nickle Iron batteries. They are tough as nails. They'll last forever (Your grandkids will probably still be using them when they retire), but there are so few choices of mfgs that there is no price competition and prices are something like $3k for a 12v 300ah battery.

[Jafo]

What about those LiFePo4 batteries with built in heating?

[littleharbor2]

Will you have a infallible charging source? Creating heat, especially on a 24/7 basis will drain your batteries if you cant keep them charged. This is why I suggested you fully disconnect your FLA/AGM batts. Once snow covers your panels you're done charging.

[Jafo]

Will you have a infallible charging source? Creating heat, especially on a 24/7 basis will drain your batteries if you cant keep them charged. This is why I suggested you fully disconnect your FLA/AGM batts. Once snow covers your panels you're done charging.

The ones I have seen will use the charging source to heat the battery (my panels) until the battery gets to a good temp.

[littleharbor2]

The ones I have seen will use the charging source to heat the battery (my panels) until the battery gets to a good temp.

So what happens when the panels get covered with snow and the heater drains them? Then your batteries are at risk of damage.

[SunEagle]

So what happens when the panels get covered with snow and the heater drains them? Then your batteries are at risk of damage.

You can either more South out of the snow belt or spend time to keep the panels clear so they do not stop generating power which can keep the batteries up.
But anyone that has an off grid system really needs a generator and battery charger for those days the panels do not generate power.

[Jafo]

So what happens when the panels get covered with snow and the heater drains them? Then your batteries are at risk of damage.

The heater only operates with the incoming charge power, not internal power. Example https://amzn.to/3KWogOj

"Only when Smart battery starts to charge, the heating function inside the battery can be turned on. When the ambient temperature is lower than 32°F (0°C), the charging current will only supply power to the heating film inside the battery. When the internal temperature of the battery reaches 50°F (10°C), BMS will immediately turn off the heating function, all the charging current charges the battery. The charging current of the low temperature heating battery is at least 5A."

[littleharbor2]

The heater only operates with the incoming charge power, not internal power. Example https://amzn.to/3KWogOj

"Only when Smart battery starts to charge, the heating function inside the battery can be turned on. When the ambient temperature is lower than 32°F (0°C), the charging current will only supply power to the heating film inside the battery. When the internal temperature of the battery reaches 50°F (10°C), BMS will immediately turn off the heating function, all the charging current charges the battery. The charging current of the low temperature heating battery is at least 5A."

Sounds like they've got it figured out. Hope it works as designed. They don't by chance offer a battery replacement guarantee in case of failure, do they?

[Jafo]

Sounds like they've got it figured out. Hope it works as designed. They don't by chance offer a battery replacement guarantee in case of failure, do they?

They have a 10 year limited warranty but I am not sure if that covers anything related to the heating feature.