chevy volt 12s/18s charging & ballancing

[altermontrealiste]

I just got my Leaf packs set up (pack 1- 6 modules pack 2- 5 modules) now I want to top balance them individually.
Joe

Just to make sure, as nissan leaf batteries are made from rectangular "cans" that contain 4 cells in 2s2p configuration, when you are talking about modules (pack 1- 6 modules and pack 2- 5 modules), you talking about the rectangular cans (2s2p)? If so, pack 1 would be 12s (charge at 49,2v) and pack 2 would be 10s (charge at 41v).

 

[altermontrealiste]

OK, so I tried bulk charging my 49.2V pack with a 48V 7.2 amp power supply, but the power supply keeps shutting off on thermal overload... I guess I need to look into getting/making current regulator, hopefully one I can adjust. Any ideas?

I don't know if this could help, but check out http://endless-sphere.com/forums/viewtopic.php?f=31&t=36958 for Fechter's Mini Meanwell Limiter V.3

 

[dnmun]

fechter's hack is to regulate the current. this guy said his thermal overload breaker is shutting down. if he comes around again maybe we can find out if the fan is not working and causing it to overheat.

 

[altermontrealiste]

how can you charge a 49V battery with a 48V power supply? 12S of lithium ion should be charged to 50.4V also.

some "48v" supplies, like meanwell or even hp esp120, can be ajusted/modded ; I dont know more about joe's setup, but that's the route I wanna take. Still, I need more infos about max charge amps as I doubt plugging 2x 45Ah12s directly in a hp esp120 would be a safe experiment to do... without further research

12s@50,4v is 4,2v/cell ; altough it gives a bit more energy, it gives you less charging cycles. The bms in a volt has never let a cell be more than 4,1v, and I'm more into the durability part of that ballance btw 4,1v vs 4,2v

 

[JoeReal]

how do you know the power supply is shutting down for overheating? does the fan turn on at all?

how can you charge a 49V battery with a 48V power supply? 12S of lithium ion should be charged to 50.4V also.

It is a variable voltage power supply. Or at least it was, I think the power supply is shot.
I am charging them to 4.08V each cell, so my 2 pack (12s+10s) is below 90V, the controllers max voltage.
I'm charging them now with a know good 24V power supply and a small balancer.

 

[altermontrealiste]

recap after 2 weeks

Hi
The challenge:
I want to design a suitable system to charge, ballance and monitor (for LVC) and stop discharge when at LVC. The less expensive, the better... but not sacrificing quality and, more importantly, battery durability. For a couple of reasons, commercial BMS don't seem to cut it.

charge system (guru advice needed)
project A (tricycle) : 90Ah12s (2p12s3p) on a 48v/"500w" lead-acid upgrade
Direct DC to battery with meanwells and original lead-acid plug & wires or HP ESP120 input 220VAC output 49vDC [AC input from : http://www.tucsonev.com/ 240VAC plug] ; could it be 2x HP ESP120, one set for 46v and the other set for 49v to have a chademo-like charge curve (higher amperage for first 70% charge)?

project B (scooter) : 45Ah/18s on a 60v/"500w" lead-acid upgrade
direct DC to battery with meanwells and original lead-acid plug & wires

ballance system for both : http://www.hobbyking.com/hobbyking/store/__10328__HobbyKing_8482_Battery_Medic_System_2S_6S_.html when in use ; 2x imax b6 ballance @4,1v once in awhile

Chemistry:
Hybridautocenter says they are LiMn2O4/LiNiO2 (no cobalt), other sources, like DocBass and http://batteryuniversity.com/learn/article/types_of_lithium_ion says it's NMC ; I don't know how having cobalt it will affect charging/discharging/ballancing.

How will having more cobalt impact the rest? Charging, ballance and discharge [guru advice appreciated]


Charging method

What would be maximum suitable charging C rate? unresolved...


Ballancing method
chevy volt doesn't need constant ballancing, nor even constant checking ; ballancing with batterymedic or iMax B6/iCharger_4010DUO once in a while is neat but not needed every day (once a week to make sure).


BMS plugs
anyone can confirm http://www.digikey.ca/product-search/en?x=0&y=0&lang=en&site=ca&KeyWords=0015247180 fits? http://www.diyelectriccar.com/forums/showthread.php/wtb-bms-harness-chevy-volt-126010.html ...

Thanks
Guillaume

 

[altermontrealiste]

Received http://www.digikey.ca/product-search/en?x=0&y=0&lang=en&site=ca&KeyWords=0015247180 ; it does fit