Help needed making a battery pack

[triop]

Hi, ive got hold of 4 x li-ion 3.7v 3400mah battery packs and want to join them in series to make 14.8v .Each pack has its own protection pcb and i can solder links direct onto this as their original terminals are mounted here.
Im confused about charging however - can these be charged in series using this charger http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=2488
any help apprieciated.

 

[Szemhazai]

You can try, but any good protection circuit will cut off the power when you try to connect so high voltage.

 

[triop]

Thanks for the reply any idea how i could best utilise these safely including charging my aim is to mod this flashlight http://cgi.ebay.co.uk/CREE-X3-XR-E-...5050558QQihZ012QQcategoryZ16037QQcmdZViewItem
Im not sure wether or not it has a driver board in it as yet it hasnt arrived
Regards Pete

 

[mattp94]

Have you had any luck with this? I'm interested in making the same battery pack myself.

 

[omg1010]

Thanks for the reply any idea how i could best utilise these safely including charging my aim is to mod this flashlight http://cgi.ebay.co.uk/CREE-X3-XR-E-...5050558QQihZ012QQcategoryZ16037QQcmdZViewItem
Im not sure wether or not it has a driver board in it as yet it hasnt arrived
Regards Pete

Hi Pete,

don't worry, that flashlight has a driver board. The torch supports 4 cells x upto 3.7V = 14.8V hence should support such a battery pack. However the PCB of each pack will support only the voltage f the pack and combining 4 of these packs will result in a combined output of 14.8V but charging will not work as the PCB's will shut at a certain voltage above 3.7V. You would need a special PCB for this which you can buy for example at batteryspace.

Cheerio
Oliver

P.S. These Hong Kong shops sell a lot of nice and el cheapo flashlights. I got myself 2 of these (e-bay nbr 280174003804) which have the cree Q5 and have a much better output ...

 

[triop]

Hi,Matt - omg1010 is of course right the pcbs on the batteries only protect to that batteries voltage and shut down when i try to charge them. . I need a 14.8v board which are cheap enough from batteryspace or allbatteries but the postage is expensive to the UK. My plan now is to remove a pcb from a scrap laptop battery and use that.
The conversion of the torch was a doddle and i've now ordered some Q5 cree's to fit, just powering it is a bit of a pain as i'm charging each cell individually. http://www.candlepowerforums.com/vb/showthread.php?t=179585&page=2
Regards

 

[HEY HEY ITS HENDO]

Cheap 18650 with solder tags in UK
http://cgi.ebay.co.uk/6-X-OEM-18650...hZ015QQcategoryZ40975QQtcZphotoQQcmdZViewItem

chargers and protection pcb

http://stores.ebay.co.uk/LEDSEE-ele...ies_W0QQcolZ2QQdirZQ2d1QQfsubZ4QQftidZ2QQtZkm

make your own packs to whatever voltage you want
........ need help? just ask

 

[triop]

HEY HEY thanks HENDO with that ebay link i've just ordered a pcb and charger for @£17 inc delivery, since the batteries are free i consider that a good deal for a 4cell li-ion 3400mah pack and charger.
Best regards
pete

 

[HEY HEY ITS HENDO]

:thumbsup:Hey no problemo ....
just how did we manage before Ebay an` t`internet!! lol

 

[omg1010]

Cheap 18650 with solder tags in UK
http://cgi.ebay.co.uk/6-X-OEM-18650...hZ015QQcategoryZ40975QQtcZphotoQQcmdZViewItem

chargers and protection pcb

http://stores.ebay.co.uk/LEDSEE-ele...ies_W0QQcolZ2QQdirZQ2d1QQfsubZ4QQftidZ2QQtZkm

make your own packs to whatever voltage you want
........ need help? just ask

Hmmm I would doubt the quality of these cells. It doesn't say if they are quality cells or used or from a stripped bat pack ... Plus soldering Li-Ion is not for newbies ... Moreover it's just 2200 mAh cells. Plus the PCB plus shrinking them plus soldering, etc. I got myself a decent pack from batteryspace (see here http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=3601) incl. tax and customs ate less than EUR 100 (around GBP 65). Without any hassle ...

I got no shares in batteryspace nor any interest with them!

 

[aemkei77]

I have the 7.4V PCBs from Ledsee in my camcorder 6600 mAh Pack, works fine, not difficult to build and for two packs, pcbs and charger I paid 90 dollars + 10 dollars for cables, shrink tube etc.

Batteryjunction would be great, nice products, especially the DIY parts and, from the specs, great battery packs, but shipping to my country is 55$


So building a batterypack is definitely an option.

The Ledsee PCBs took 10 calendar days to arrive (Austria)

 

[Brum]

Hmmm I would doubt the quality of these cells. It doesn't say if they are quality cells or used or from a stripped bat pack ... Plus soldering Li-Ion is not for newbies ... Moreover it's just 2200 mAh cells. Plus the PCB plus shrinking them plus soldering, etc. I got myself a decent pack from batteryspace (see here http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=3601) incl. tax and customs ate less than EUR 100 (around GBP 65). Without any hassle ...

I got no shares in batteryspace nor any interest with them!

LED-SEE sells Panasonic 2400mah's, should be pretty good quality.
They haven't failed me yet. Soldering/welding can be a pain, thats why I use wired magnets.

"Just" 2200, just a little less then what the main market players are selling. Seem to be all 2400 and a few 2600's from LG.

 

[triop]

Have you had any luck with this? I'm interested in making the same battery pack myself.

Hi, Matt my bits arrived from the supplier that Hendo suggested, had to remove the original cell protection and soldered it all up. Run through a couple of cycles and works a treat, only complaint is that the charger doesnt come with a 3 pin adapter but no real issue

 

[eddielee70]

I tried building a 2 cell 7.2v and 4 cell 14.8v pack. but no luck

http://www.candlepowerforums.com/vb/showthread.php?t=182949

easier and safer to buy one