Powerbasement offgrid solar installation

[TimV]

Hello everyone.

I aim long saving 18650 li-ion batteries and the time has finally come to start building my own version of the Tesla powerwall.

I have this basement and spacewise i will be building a powerrack instead of a powerwall. This rack will contain about 80kWh in a space of 0,8m x 1m x 1m90. So verry compact.

In a perfect world. I have enough space to fit 5 of those racks in my basement. But lets build the first one before dreaming of the next one.

The plan:

24 solar panels of 300wp.
So far 24kWh of lithium
And evaluating what kind of electronics i will use.

To follow me:

Here is my first video of the build.
I hope you enjoy it!

If you have questions or suggestions. Please feel free to shoot those to me.

Thanks

https://www.youtube.com/watch?v=Snl7nzdB3Es&t

[oil pan 4]

There is no way I would put a bunch of those batteries in my basement. Maybe in a shed.

[TimV]

Where i live in winter it freezes. So the room where the batteries are in can not be some shed. Or i need to super isolate it and put a heater in the shed... You cant charge lithium when freezing.

[jjackstone]

What is the source of your cells? Were they bought new or harvested from old electronics? If harvested, have you done an internal resistance check on the cells? That seems to be where most of the problems arise from using older mismatched cells. Good luck with your build.
JJ

[oil pan 4]

I would do some kind of insulated, heated battery box before I brought them inside.

I'm well aware of what happens to lithium ion batteries when they get cold.
Stated using LiFePO4 back in 2011 and started driving a nissan leaf last year.

[TimV]

Originally Posted by jjackstone

What is the source of your cells? Were they bought new or harvested from old electronics? If harvested, have you done an internal resistance check on the cells? That seems to be where most of the problems arise from using older mismatched cells. Good luck with your build.
JJ

I only do a capacity test. If they don't have 75% from new. They will not be used in the powerrack.

My source are used laptop and e-bike batteries.

[jjackstone]

Ok. I'm guessing then that you have watched a number of the Youtube videos from the likes of JehuGarcia, The Australian Powerwall guy(can't remember his name right now), and others. You really need to get a charger that will test the internal resistance even if the battery capacities are pretty well matched. When those guys have had their fires, that is often where the fault was found. Higher resistance = more heat = fire eventuallyt.
JJ

[teoman]

On aliexpress there are some ebike modules wiyhout any cells in them.

If i were in your shoes i would be trying to build big modules out of those so you can carry some to your car when you want to boost the electric range.

Kind of like the scifi power modules (or the spore drive canister nonsense on the new StarTrek)

[oil pan 4]

I would just use something like battery modules from a nissan leaf.

[TimV]

Those are unfindable in Belgium...