Recharging li po batterys

Thread Starter

geoffers

Joined Oct 25, 2010
475
Hi all,
I've just got some 3.7v single cell lipo battery's, the data sheet is a bit chinenglish?
They have a r5402n101kd-tr-f in the pack which protects from over current ,over charge.
It says supply for that ic is up to 12v , max charging voltage for the battery is 4.20 v +/-0.05v
I'm still not sure how to charge them, can I use a 5v wall wart type thing which is easy to get hold of and leave the on board ic to sort it all out, or do I need to include a lipo charging ic in my circuit to make sure the battery charges safely. Most of the ones I have seen need around 6.5v supply though, not as common as a 5v phone charger/USB etc.

Thanks Geoff
 

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JWHassler

Joined Sep 25, 2013
306
Would be better to see the datasheet of the charger, rather than its constituent IC.
That said, is it something like this?
I've bought a few of these, and they just work. Connect 5 volts an go.
But *don't* get the one with a 'mini-B' connector: you want 'micro-B'
 

Thread Starter

geoffers

Joined Oct 25, 2010
475
Hi,
Thanks for the reply, not quite like that, the ic I attached the data sheet for is built into the battery, those boards do look neat tho!

I was just trying to decide if its safe long term to charge at 5 v or if I need to add something else to control the charge.
It looks to me like it ought to be OK, but I had a friend a few years ago who used to charge lipos for model planes under a up turned dustbin with two concrete blocks on top for when they exploded.....
Cheers Geoff
 

Thread Starter

geoffers

Joined Oct 25, 2010
475
Thanks,
I had a look at that, google translation is pretty good, still not 100% sure that the Ricoh chip in my battery will allow me to charge with a 5v supply?
I might try it , I've flattened one now, rang Darnell tech support here in UK and the chap said, don't know!
Cheers Geoff
 

Thread Starter

geoffers

Joined Oct 25, 2010
475
Thanks Dave ,
I've just been going through the data sheet again and read this bit...

After detecting over-charge voltage or over-charge current, if the battery voltage is lower than over-charge
detector threshold voltage, the R5402N101KD can be reset and the output of COUT becomes “H” when a
kind of load is connected to VDD after a charger is disconnected from the battery pack. If a charger is
continuously connected to the battery pack, when the cell voltage becomes equal or lower than the release
voltage from over-charge, over-charge will be released and COUT becomes “H”.

I guess this means I'm pretty safe for 5v charging? Those little 5v USB chargers are everywhere and convenient :)
Cheers Geoff
 
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