Rebuilding li ion HID battery pack

[ROADSTIR]

My 5 year old generic HID flashlight battery pack has finally stopped taking a charge, so I decided to perform an autopsy, remove it from the black plastic tube, and see if I can rebuild it. Since it's a generic and the mfr is no longer with us (at least as we know it) a replacement is probably not available. Plus, I've seen prices of $100 or more for similar batteries. No thanks.

There was a blue shrink wrap and under that there was a thicker, white plastic wrapping covering the 6 18650 cells. The label said:

11.1v output and 5200ma

1. Would reverse engineering and replacing the cells be a major project? I'm fairly handy, can solder (not ideal, I know), and am willing.

2. If I decide to take this on I know I need to try and match up capacities on batteries. Is there a way to buy matched sets?

3. What would some suggestions on ideal replacements be?

Finally, I read a post from back in 2005 where another member stated that Battery Station would build your pack for $5 if you bought the batteries from them. I've already emailed them and asked about this. If they do, my question on battery suggestions still stands.

Thanks

ps. The darn thing looks like a $#%^$ bomb, doesn't it?

 

[VidPro]

piece of cake, tabbed where you would solder at, color coded wiring, protected and is that a thermal fuse that is on the protection board?

i would use some tabbed sony or tabbed LG cells of high capacity without it being the highest capacity today . like 2400 or 2600.
to Match you test them, good cells will be pretty well matched, if the test shows one being off, then you wish you had bought an extra.

get some battery shrink wrap to finish it .

it looks like 3 in series then that series is parelleled?
you see normally i would want to pair up the parellel cells first, then series them. but that dont make much difference anyways.
as long as you just repeat exactally what they did, with new cells.

I always discharge them (within Spec) (part of the test anyways) prior to assembly, so if i get a short or do something stupid , it is not as bad.

You got the light apart right? you can put it back together the way it was Right?
Can you pull it off,
Heck yes, and i only build my own and do my own pack replacements because i dont want any lesser cells, and i want to test the cells fully first , and that takes time and time is money, so if they are to do it for less $$$ than i can do it myself, they will do so with some junk cell items, or not test as long, or miss something i think is important.
even if you totally miserably failed and ruined the entire pack and every cell in it, you could probably do it a second time and have been money even over paying someone to do it for you. and then you have the skill.

depending on where it goes, how it is charged, and if i could wedge in the connector for it, i would add in a balance connetor tap, even if i used it only rarely. adding in balance ability can get the cells fully re-balanced, fully charged, entend longevity, and can give you and outside picture of the cells inside. and it would connect where your already connecting the protection board anyways.

ps. The darn thing looks like a $#%^$ bomb, doesn't it?
yes it does look sorta like they might have used Sony cells, and they are "the bomb"