Lithium Ion Charger (10 Cells/Batteries - each 2400mAh)

[svebee]

Hi guys, I have a simple question, is it possible to create one charger who could charge 10 Lithium-Ion batteries in parallel (each capacity 2400mAh - **broken link removed** - totalling 24000 mAh) - source would be wall-socket (Europe - 230V) ofcourse with transformator, rectifier...

What current/voltage I need for these guys?

I searched over internet and I could find charger for max 3-4 lithium ion cells, do I need to split up these (10) in smaller "groups" and charge them seperately or..?

When they would be full, they would go on USB port (5V) for charging mobile phones, MP3 and so on....


Tnx. for any kind of information.

 

[audioguru]

Poor quality lithium rechargeable battery cells catch on fire.
I would never buy a no-name-brand lithium rechargeable battery cell with the word FIRE in its name.

The output voltage will never be as high as 5V so your battery idea won't work.

 

[MrAl]

Hi,

I dont know if i would buy a cheapie charger either, but it would be possible to design a charger that could do 10 cells. It would just have to be 10 of the same circuit really.
For 10 cells each charging at 700ma each that would be 7 amps from the transformer unless you use a buck converter and use a higher voltage transformer for the main power.
Of course 10 smaller transformers would work too. 10 wall warts however would get to be a pain.

 

[svebee]

Poor quality lithium rechargeable battery cells catch on fire.
I would never buy a no-name-brand lithium rechargeable battery cell with the word FIRE in its name.

but they have pretty good reviews? then if that's not ok, what type (brand/model) do you suggest?

The output voltage will never be as high as 5V so your battery idea won't work.

what about DC/DC boost?

It would just have to be 10 of the same circuit really

sure, but I though if there would be some "universal" circuit for 10 of them simultaneously. but if there's no other way, that would be it...but, what circuit do you suggest? so then I just multiplied it 10 times (for each battery) - because I don't want some extra expensive solution. Something from Linear Techology, Atmel, Maxim or...?

 

[MrAl]

Hello again,


You can't really make a 10 channel charger without regulating each channel individually anyway, and that means some kind of voltage regulation for each channel. You can however use the same input power source if you want to, such as a 9v, 10 amp secondary transformer and appropriate rectifier and filter caps. That would give each channel a full 1 amp capacity.

You can make chargers quite simple from LM317 even, with decent properties. You may have to measure the voltage of the cell first that's all. If you are interested i'll post a circuit. This would mean 10 times LM317 plus a few other parts per circuit. That could mean under 20 dollars (not including case and battery holders).

 

[audioguru]

I have some li-Ion batteries from cell phones and a laptop that have two cells welded in parallel. They have a protection circuit with them that probably prevents deep discharge and over-charge.
The extremely high quality Li-po batteries for my electric model airplanes and helicopter are ThunderPower brand that are assembled in the USA.