Glubux's Powerwall

Thanks for the update.

To balance the packs, did you consider getting them all fairly close - then connect them all up in parallel overnight ?

This method is a lot quicker than using your charger, and won't cost you any energy as the process simply shares what's already stored.
 



That's how I do it , no charger ;)

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Ah, seeing different voltages on your meters made me think you'd got a charger out of shot - the actual voltage across each cell (when in parallel) will be identical - so you can now see the errors in those meters.
 
Sean said:
Thanks for the update.

To balance the packs, did you consider getting them all fairly close - then connect them all up in parallel overnight ?

This method is a lot quicker than using your charger, and won't cost you any energy as the process simply shares what's already stored.
Click to expand...

As has been shown many times, this method does not work.
For it to work, charge voltage and rest voltage would need to be the same. They are not. Charge voltage is always higher than rest voltage. Secondly, it would require 100% charge efficiency, which is impossible.
 
It works perfectly well - its how commercial bank producers have been doing it for decades - its how folks living off grid have been doing it for decades.

Feel free to convince me that it doesn't.
 
Update :

The packs are doing their job pretty well.
I received my balancers:

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<!-- m --><a class="postlink" href="http://gne2010.com/productitem/1091">http://gne2010.com/productitem/1091</a><!-- m -->

They are a bit expensive, about 20 per pack, I don't really know how they work (they share some 4.3V AC) but I like the fact that they don't bleed the highest pack but transfert the energy to the lowest.
They seems to work pretty well, keeping the difference of 0,05v max no matter the state of charge:

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This is still a bit ghetto style but it's enough for testing
 
Hi Glubux,

I really do like you work!
Do you have also lead acid battieries (on the right side)?
Do you use lithium and lead acid in parallel? If yes how do you do it?

BigBen
 
BigBen said:
Hi Glubux,

I really do like you work!
Do you have also lead acid battieries (on the right side)?
Do you use lithium and lead acid in parallel? If yes how do you do it?

BigBen
Click to expand...

Hi Big Ben, thank you ;)

Those are my old forklift batteries, I keep them for now as a backup (and mostly because they're super heavy) but they are not connected.
As soon as my bigger packs will be running, I'll get rid of them.
 
I have no Idea, some french website says around 1 per kg but I thing it is for pure lead.
 
Sean said:
Don't just give your old battery's away for free :)
Click to expand...
They're not exactly mine, I borrowed them from work from an old lift fork out of order, I think i'll put them back once my powerwall is big enough.
 
That's the neatest I've seen those balancers layed out. Was considering using them but making a whole wiring harness for them and having them remotely located to keep things tidy. But that would be one hell of a job I thinks.. Pete
 
Noticed you guys using those little green and white backed meters for voltage.
Ive tried them (as has Pete) and found them to be, less than sterling.
Low end voltage cut off is too high. Accuracy at each end of range gets wiggy.

Ive used these : <!-- m --><a class="postlink" href="http://www.ebay.com.au/itm/17151434...49&var=470538978477&ssPageName=STRK:MEBIDX:IT">http://www.ebay.com.au/itm/171514345083 ... EBIDX%3AIT</a><!-- m -->
(sorry not a commercial ad, just for reference)

And found the Green and Red meters go all the way down to 2.49v but the blue only do about 2.6-2.7v
They have a pot screw on the back, so you can hook them all up to the same voltage source and calibrate them.
The voltage is inline with what most multimeters read.

Lastly, you can actually get cheap multimeters for around $5 that you can jerry rig into 9v of lithium and run your banks with those.

kind regards
 
hbpowerwall said:
That's the neatest I've seen those balancers layed out. Was considering using them but making a whole wiring harness for them and having them remotely located to keep things tidy. But that would be one hell of a job I thinks.. Pete
Click to expand...

Thanks Pete, it's really complicated to make a neat wiring with those balancers, I'm not happy with it, i'll find better solution next time. Though it works pretty well.

BTW 3nergE, it doesn't show on the picture but my voltmeter are yellow one, they fade around 2v and have the pot screw behind ;)
 
Here is an update about my new packs, I decided to go "big" to avoid having too much parallel 7S strings to reach 20 kwh,
So instead of 80 cells 100Ah packs, I decided to double the number of cells and raise the cutoff to 1500mah per cell instead of 1200mah.
This should give me around 250 Ah per packs and around 20 kwh with 3x7S strings.

I decided to fuse both side for extra safety and also to avoid overheating the cellswhile soldering, which works really well. The drawback is if you accidentallyturn a cell while you grab the pack, you might broke a fuse.


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Nice work there m8!
 
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