Hi guys I came across more second hand laptop Batterries  if anyone is interested.

 

I can give them to you for R10-R15 a laptop battery, depending on how many you take. I’m based in midrand. They’re perfect for DIY powerwall and small projects!

 

there is too many for me to add to my power wall.

Hi Stok. On average , when I tested, I had usually all were good, or 4 were good, or all were bad per pack. Depends on the pack. The average Mah can vary, but I managed to make about 3x 24V packs with about 280 cells, all above 2000mah, some closer to 3000mah. I’d say a definite good yield of about 50% cells made it to my power wall. 

Edited November 18, 20205 yr by beserker786

They’re still as laptop batteries. Sell them per laptop battery . The amount of cells depend on which battery it is

9 hours ago, beserker786 said:

 The average Mah can vary, but I managed to make about 3x 24V packs with about 280 cells, all above 2000mah, some closer to 3000mah. I’d say a definite good yield of about 50% cells made it to my power wall. 

How did you build a battery pack?  Did you use a system from someone or from scratch?

 

Edited November 18, 20205 yr by Pietpower

So I 3d printed cell holders for the Batterries, soldered on the fuses, hooked them together 7p, got a 24V cell meter balancer. And connected the terminals to the battery connection on the inverter. I’d say tested the cells and built the battery from scratch.

8 hours ago, beserker786 said:

So I 3d printed cell holders for the Batterries, soldered on the fuses, hooked them together 7p, got a 24V cell meter balancer. And connected the terminals to the battery connection on the inverter. I’d say tested the cells and built the battery from scratch.

Please post a pic of the final battery showing the fuses and balancer.

These builds interest me more than the 'second life' batteries you can buy from the local Li battery suppliers. What I understand of these is they are imported from China as 'second life' and you pay good money for them.

At least with the 18650 battery packs one gets them for nothing (or close) and you can sort the good from bad. 

What I need to know from those who have done this and built their power wall battery is what is the important criteria when sorting: capacity, internal resistance etc. ??

Hi

I reckon these builds sort the serious enthusiasts from the ouks bragging about how big their systems are.. ('my system's bigger than yours..')

The only thing I'm still trying to get my head around is how to maintain the individual cells (or the banks). How do you know their capacity has dropped or cells have died..?

Hi Beserker,

Yes, I need more 18650 cells, will buy laptop batteries untested.

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