Battery Pack Conversion Project

[Component]

Hello Everyone,

First post here.

I have a Li-ion battery pack for a flash unit. It was DOA and is far to expensive to replace.

I wanted to ask if it's possible to turn the Li-ion pack into a AA recharageable battery pack?

The batteries would be swapped over for recharging. May be AA Ni-CD or Ni-MH?

The data on the cover reads:

DC 11.1V 2000mAh 22Wh Li-ion. There are +- signs on the contacts.

I have photos of the battery pack, but incase I can't post them, the pack's dimensions are approx 2.1" x 2" x .8" ... or 5.4cm x 5cm x 23cm.

Inside the unit there are 3 thin gray packets that are the battery cells that are attached to a circuit board that's soldered to the two contacts.


Any suggestions of a way I can get the pack working with the flash again?

If not, could an external pack be made that could be wired through the casing to the contacts - so the case slots into he flash unit and power fed externally?

Thank you for your help. I look forward to your inputs of the matter.

BTW - new to this forum so unsure how topost pictures of the battery

 

[Audioguru]

The 11.1V Li-ion battery will be 12.6V when fully charged. Replace it with 9 name-brand AA Ni-MH cells in series.

 

[Component]

Thank you for your fast reply.

Regarding your suggestion. I would like to use less batteries because I would have to double up on the number for back-up in case the flash unit ran out of power.

I can't find anything above 1.2 to 1.5 volt rechargeables, and anything higher goes back to Li-ions. I saw a 4 pack AA Li-ion set somehwere. They were cheaper than the battery pack in question. Can you use them in a normal charger?

I have another idea I appreciate you electronic advice on . What if I used something like this instead: http://www.argos.co.uk/product/9829701

It supplies 12volts of DC current. I assujme wires would connect the contacts to a socket on the original basing that the power adapter would connect into.

In all cases a multi-meter would be used to check the power on the contacts in case the flash unit got zapped! And the PSU option would ensure the flash unit doesnt drain.

Thanks again

 

[Audioguru]

I have never seen AA Li-Ion cells because they are not supposed to be able to fit into the battery holder for AA alkaline, Ni-Cad or Ni-MH cells. They are usually a larger 18650 size (18mm diameter by 650mm long).

The "power adapter" has an expensive switch (that will usually be in the wrong position) and many plugs that you do not need. It has no details and does not even say if its output is AC or DC or the amount of current. Buy a less expensive 12VDC adapter instead that has enough output current that is needed.

 

[Component]

I take it the Li-ions couldnt be recharged in a standard charger anyhow? So that would be more out lay on another recharger. I saw this adapter:

http://www.maplin.co.uk/p/12v-500ma-acdc-power-supply-n93ju

There was also one of these:
http://www.ebay.co.uk/itm/Quality-1...PTER-Transformer-LED-Strip-CCTV-/121288057046

I think the ebay one looks too powerful? The Maplin one might be a better one.

I take it I just wire the contacts through the case to a socket (that goes into the unit), and then I can connect the adapter to the socket externally.

Thanks again for your forum support

 

[Audioguru]

Lithium is extremely reactive and will explode or catch on fire if a Lithium rechargeable battery is charged or discharged wrong (too much voltage or too much current). Those power supplies are not a proper charger. Learn about it.

 

[Component]

Yes, I do understand Li-Ions can be a bit dodgy.

The original battery pack for the flash unit caused the flash to over heat quite badly. When the pack was later charged it became extremely hot and the casing began to swell. So that was the end of the old battery.

Thats why I was looking towards making a new pack out of normal rechargables - more relaibale and safer ... and cheaper LOL!

The power adapter idea sounds like a good idea as well, so I will investigate the best options.

Thanks again for your forum support and all the best