Lithium batteries in hot climates

Wheelman55

Esteemed fellow forum members. Can you speak to what effect high temps might have with storing lithium batteries?  Cycling them in hot temps will certainly shorten their life, but how about storing a shut down battery?

In our case (Sonoran desert, TX) we shut our system down for the summer months.  We shut the system down beginning of April and start it up late October/early November. Temps inside the battery shed likely stay in the 90’s F for much of that time. High temp on the min-max thermometer showed 97 F this past summer (2023). 

We use Discover 42-48-6650 x three batteries. These batteries have on-off buttons. With the batteries turned off, self discharge is very small over the months the batteries are stored.

Thoughts?

SteveK

Actually your temps aren't really that high for Lithium batteries. You are inside the optimum thermal window for full cycling and not just storage. When you start to exceed 110-114F there are issues with operation causing reduced longevity. 97F should allow full cycle count over the life of the battery.

Always wondered why folks that live in the desert don't take to below ground cooling methods more. There must be some relief down below ground. Too hard to dig maybe?

Wheelman55

Digging down is one of the many things that I didn’t think about when building our personal paradise in the desert😀

We did dig down to bury 8,500 gallons of water tanks. Came up 20” short on the desired depth due to hitting bedrock. Decided not to jackhammer. Left a bit of a burial mound effect in the side yard☹️

SteveK

Now that's a lot of jackhammering! Can see why you decided not to do it. I would think it might be possible for a simple storge solution for your batteries if you felt the need to cool them more.

I live in the northern forest so my needs are more skewed toward keeping things warm enough. Shallow bedrock all around, exposed ledge outcrops and fields of glacial boulders are my norms. I tend to blast my way through things from time to time. I use Sierra Blaster, a localized explosive device. No licensing required and when used correctly is a force multiplier. Here's a video if anyone is interested. Skip to 9:11 for the blast. https://www.youtube.com/watch?v=Xne_OZtRv5s

Wheelman55

Fun video. Our hole was 40’ x 12’ by as deep as we could get. We found bedrock towards one end, extending the full 12’ width of the hole. Would have been an adventure with the Sierra Blaster🙂