Charging basics? LiMnCo?

[Drunkskunk]

I'm still searching for a good solution to my charging problem for Lico batteries.

I understand propper charging for LiCo, how not to charge above 1C, monitering them the whole time, ect.

What I don't understand is the tech side of whats going on. Is it being charged just by a CC, CV source? is it a ramp up charge? Is it posable to build a charger for LiCo?



While I will use a BMS to charge through, for the sake of understanding, lets simplify things and leave out any form of BMS, and charge directly from a charger to a stack of cells. Can it be done by just using constant voltage and constant current?

 

[fechter]

As far as I know you can charge them CC, CV but you need to terminate the charge as soon as the voltage gets up to the end point.

 

[TylerDurden]

BU has some good info:

http://batteryuniversity.com/partone-12.htm

 

[Drunkskunk]

Great link!

The Itselectric batteries came with 37V chargers thatare the size of laptop battery chargers. They have no cell management, but the right voltage detection for LiCo.

What I think I might do is get some of Justin's Lithium BMS units and build up a new battery from RC plane cells. Its looking like I may have a BMS failure on my other Itselectric battery now, and I don't want to throw away money on a new set of 2C batteries if I can build a pack of 10C for close to the same price

 

[Drunkskunk]

Alright, rather than starting a new thread, i'll keep this one going.

Who makes the best BMS for Lithium?

And what is the general opinion of only using the BMS only for charging?

 

[Ypedal]

Best BMS ?? good question.. let me know if you just fine one that works at all properly ! :x

Unless you need to drain the pack way down.. a BMS on discharge is not a must..

Thunder power ballancer hooked upto a thunder power 1010C charger, via data port, is working great for me so far !!

 

[Drunkskunk]

That 1010C, will it charge 10 cells at once? And does it run through the balance cycle fairly quickly?

 

[Ypedal]

Yep, up to 10 cells ie: 36v ( 42v fully charged )

The ballancer feeds data to the charger and stops it if any single cell is out of the safety zone.. depending on the level of imballance, there seems to be a limit of how many amps can be fed to the pack, or i just have not learned how to set it up correctly.. but with the ballancer hooked up i'm limited to 2 amps.. without the ballancer i've charged up to 5 amps but you need to feed the charger 12v, so either big SLA's or a 12v power supply.. ( I have this unit in the mail )

http://cgi.ebay.ca/ws/eBayISAPI.dll?ViewItem&rd=1&item=220237137527&ssPageName=STRK:MEWN:IT&ih=012