520 cell and i keep counting

C

costty

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Jan 21, 2018
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Hi from Romania

The first time i started to unpack laptop batteries out of curiosity, but i realized they still have a potential that i should exploit.

I have an MPP Solar inverter 48v/5kw and i started to use 4 lead bateries @155A. In time i made some tests an try to make a powerwallcomfortable to operate and to make some improvements. So i take the decision to go on small blocks on 13s10p 48V configuration.


and it started:

many cells .....testing, testing.....retesting...... I have to make a charging station with TP4056 for cells grater the 3.7v and one adjustable step down power supply for overdischarged cells

i put some pictures so maybe someone take some ideeas or not :cool:

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[size=small]I'll come back with pictures of the 48v blocks[/size][/size]
 
Welcome ...

It often starts with curiosity and addiction follows... ;)

For a 48v batterieyou need a 14s setup , and you might go a bit bigger for a 5Kw inverter... 10p is a bit small...
 
wim said:
Welcome ...

It often starts with curiosity and addiction follows... ;)

For a 48v batterieyou need a 14s setup , and you might go a bit bigger for a 5Kw inverter... 10p is a bit small...
Click to expand...

thanks...

the 13s10p setup it's very ok for me...for the moment i running 2 blocks in parallel with 4 vrla battery. if my calculations are correct (correct me if im wrong) 13s @ 4.2V (HI cut) it's 54.6v the bulk charging for vrla and Lo Cut 13s @3.2V is 41.6V ...i set from the charging disconect voltage @ 40V for all batterys

i see many users to go on 14s setup and 50p..60p.... for me is a problem replacing a bad cell....it's take time and in time of repairs the grid is off ....so i make small blocks at 48v 13s10p - 48v@20A to run theme in parallel mode. the target is 20 blocks and never stop (the addiction)....and if one have a problem i get it off and what? ....i loose for the repairs 10% off capacity ! not going off in total
 
Beware of that you suck out alot from the Lithium cells running them in parallel with Lead. Since Lead acid will as soon as topped up go down a volt or 2 in resting that will steal alot of juice from the Lithium cells.

If thats fine then you are set and can go with it. You can have disconnection switches to but you need to know what you are doing and how different those 2 chems are.
 
daromer said:
Beware of that you suck out alot from the Lithium cells running them in parallel with Lead. Since Lead acid will as soon as topped up go down a volt or 2 in resting that will steal alot of juice from the Lithium cells.

If thats fine then you are set and can go with it. You can have disconnection switches to but you need to know what you are doing and how different those 2 chems are.
Click to expand...

thx Daromer for youconcern , i notice that but i have some hungry pumps at the heating system so that drop is disappear very fast
for the moment form the invertor i thake at most 1-1.5kw like a backup for heating system and light on 12v (light on the house is provided from a step down converter)
i intend to replace the lead battery with Li but for the moment i have 2 blocks ready, 1 in final stage (need more fuses to complete and the BMS) and i finish to test another 290 cells ~ another 2 blocks....when i get ready 10 blocks i will disconnect the lead battery and i will use theme only for light system
 
If you take some high voltage schottky diodes (the type used for solar panels) you can isolate the lead acid strings from the lithium strings. Then you connect your appropriate chargers between the diodes and strings. That way you aren't constantly charging the lead with the lithium.
Use about 4 - 6 of them for each leg. You will only experience the 1V or so voltage drop (you can shop around for lower values) but the amount of current will shared evenly. So for each separation string you'd have 8 - 12 diodes.
Note: You only need to separate the chemistry, no need to separate like chemistry strings.
 
Korishan said:
If you take some high voltage schottky diodes (the type used for solar panels) you can isolate the lead acid strings from the lithium strings. Then you connect your appropriate chargers between the diodes and strings. That way you aren't constantly charging the lead with the lithium.
Use about 4 - 6 of them for each leg. You will only experience the 1V or so voltage drop (you can shop around for lower values) but the amount of current will shared evenly. So for each separation string you'd have 8 - 12 diodes.
Note: You only need to separate the chemistry, no need to separate like chemistry strings.
Click to expand...

I get your point but i use for the moment the charger from the invertor so the diodes dosent help me
I whant to install a mppt charger separate to remove some heat inside the invertor but in time a shall change the lead to Li
Thanks anyway.... Its a good advice!
 
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i just save this from scrap yard....
I gone to make powerwall ver. 2.0 ::)



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this is my old setup for testing.... Ver. 1.0
 
Wow! nice! :D
 
After 4 hours... Screws and cables... Save a lot of inside goodies.... Its empty


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I have to think about some isolation.... Winter is coming :)
 
I know of a place you could send some of those contactors ;) :rolleyes:
 
Actually, if you are willing, you could post in the Marketplace and sell some of them. Could help offset some of your costs
 
I'd buy some from ya, if the shipping wouldn't kill me :p
 
concret....hard

the cabinet in position
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let's put some shelves and to see some cells inside to test the space
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[size=medium]now i have toface another challenge...rebuild the packs 120p and i need to consider buying batrium BMS[/size]
 
can i use grafana with my pip-5048 ? in the last days of testing the pip-5048 is writhing in data some values like batteries gos up to120v, amps over 400 !, i need to run other software more precise
thanks for any help
 
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