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Glubux's Powerwall
Thank you Paul Wink

Update, 6 packs are ready now, the 7th will be ok very soon.

mike1979 likes this post
Hi Looking good i like you idea of using copper wire for he busbars i have copied you design within slight modification will up load pic soon, also how are you capacity rated your packs i see some of the have cells missing???
good work keep it up....! :mrgreen:
Sdsparrow likes this post
I decided to make 100Ah packs with a maximum size of 80 cells, the lowest cells I used are between 1200 and 1300 mah ( 1250 X 80 = 100)

I'm building 7 packs, running some test and if everything is ok I'll build bigger packs this time, 160 cells, minimum 1500mah, 250 Ah

Looking forward to your build!
Love the effort into making them look smart. Don't look anything like used laptop parts any more Smile good work.
Chris Evans likes this post
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HI looking good how do you intend to mount it to the board / wall ??
I think they will be on a shelf at first, in a garden shed, with one shelf per string but this is not completely clear in my mind, I ll post some pictures later.
Hi Glubux

Nice pictures they look very good.
Which camera are you using?
Really looking forward to new updates


I'm using a Nikon D7200 with a 17-55 F2.8 and a 85mm F1.8, great lenses!
Just a teaser for tomorrow, the packs are ready to plug, I hope it will be a sunny day!

mikesdiypowerwall and Solexx X like this post
A little update here after one week of lithium power!

First thing, I really like how the cells react compared to lead acid, the charge efficiency seems a lot better, no waste in absorption.

They hold the load very well too, the voltage goes down very slowly and predictably.

I didn't try big loads yet, the biggest was the hoover, a bit above 1200W and absolutely no sign of warming, I'll try to drain more power in a few days and watch with the thermal camera, but first I need some sun to charge.

I had an issue though, I let everything plugged during the night to see how well it hold the charge (2 fridges, the inverter, the 18650 process...).
During the 5 first nights all was ok, there was remaining around 20% energy in the morning, but in the 6th night the voltage dropped dramatically, 4 packs were still at 3.30v, the next one was 3v, the next one slightly above 2v and the last one slightly bellow 2v...

That's the goal of testing I guess, so I unplugged every packs, recharged to 3 volts the lowest and then went to work thinking about what happened.

And the interesting learning that comes out of this is than the biggest voltage drop was in the pack with the less cells. Just a reminder, I decided to make 100 Ah packs by matching the number of cells, 80x 1250 cells for the full pack and 51x 1950 for the more empty. I knew this wasn't going to be perfectly accurate and now I can see clearer. Those simple math are done with the capacity mesured with a 1C discharge rate, but we now that if you discharge at a lower C rating, the capacity raises, my guess is than it raises more on a 80 cell pack than on a 51.

So I add a few cells in the packs (very easy to do BTW), re-balanced them and I'm looking forward to see how it goes.

One last thing about balancing, the first time I blanced them (at 3.8v), I noticed than they were drifting a bit while reaching full charge (4v) and same thing with low voltage (3.3v) but everytime they were around 3.8v, the balance was still perfect. Two conclusion : first, this was a clue that some packs were a bit weaker, the ones I noticed then were the ones which fell around 2v. Second thing, I think as long as you don't reach the top or the bottom of your packs, they can be slightly uneven without unbalancing.
thanar, nikita, Wattsup And 1 others like this post

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