Charging Lipo with Li ion charger?

[adrock8519]

Hi, I have this Mini folding electric bike and it has a 29v Lion battery in it. The charger says 29.4v/2a and I have verified the battery volt with my multi meter.

I need more Amp hours and am planning on simply putting a switch to swap between the battery packs.

I was thinking of buying this:
http://www.alibaba.com/product-gs/1474230313/24_volt_li_ion_battery_18650.html

or just using a 7s Lipo but Im unsure if the charger in the photo here will be safe to charge a lipo?

any help would be much appreciated
adam

Ps Can any one recommend a good switch?

 

[wesnewell]

A 7s rc lipo pack will not have a bms like the pack you linked to, and probably your current pack, does. For safety, you should really have a 7s or larger rc balance charger. Or you could just wire the new rc pack in parallel with your current lipo packs bms and forget the switch.

 

[dogman dan]

You can do it, IF...

You have a pretty lax idea of what is safe. Don't do it in a place you wouldn't build a campfire.

The key thing will be whether your existing charger has the right voltage output for the pack you choose. It's not clear to me what 29v means. To state the obvious, your new pack must have the same number of cells as the old one. Is the old one 7s?

Bulk charging lico naked, I would advise setting a charger for 7s to 29v or less. Not more that 29v full output.

Wiring up your new cells to be in parallel with the old pack at cell level, thus connecting them to the bms, is very good advice. To do this, you will have to connect each cell of the new pack with each cell of the old, preferably using fairly thick wire to replace the balance wires. Then still connect at the main wires for the discharge power to flow there.

 

[adrock8519]

The problem is the battery has been glued within the tube of the bike and we burst the battery in another identical bike trying to get it out. I know its a Li ion and I know the charge says 29.4 v on it plus I used multi meter to check the fully charged battery and it was 29.4v I presume that it is a 7 cell as if you divide 29.4 by 7 you get 4.2.

How about I use a hobby king battery medic set to discharge if the cells goes over 4.2?

cheers for help
adam