Charging a Bosch 10.8V Li-ion

[TheAmmoniacal]

I got a Bosch Drain/Pipe Inspection camera from a friend some time ago, it was no longer working so he said I could keep it. The LCD is just showing white, after some time black stripes/lines will run across the screen, and that's it. I've failed to find anything wrong with it -- so I thought of some other uses for it instead. My first thought was to convert it into a flashlight, with the nice handle and large battery. This is the unit:



But I never got the charger for it, and I'm not sure if it's worth buying (the charger alone is $100 here). So my question is, how would I charge this battery? Could I make my own charging circuit? Will other Li-ion chargers work, like the turnigy? In this case, I'm not even sure how I would connect it, the Bosch battery has 5 connectors, the + and - are on the top here:

But you can also see the three pins on the side, do the battery have internal circuitry?

What are my choices, can I use the battery without having to get the original charger?

Thanks.

[Whales]

Can you open the battery-pack to have a look inside?  The best we can do is guess, unless someone here has past experience with these packs.

[amyk]

10.8V = 3 * 3.6V

You likely have 3 standard lions in series, probably 18650s. 5 connectors suggests the connections between cells are also brought out for balancing, and maybe there is 1 more connector for a thermistor. You could measure the voltages between them. Open it up (carefully) to be sure.

If it is a 3S pack with the balance connections then you can charge it using a standard hobby charger that supports balancing, otherwise you can still charge each cell individually with a single-cell charger (you'll need to check that all the cells are at the same voltage after charging them.)

[M. András]

i have a charger for this but you cannot find a shematic for it not even get one from bosch, as these are not their designs, if pictures from the unit helps at all i can make some but i wont open it as its 2 months old and i want to keep my 3 year warranty for the tool

[TheAmmoniacal]

Here's the circuit inside the battery, and yes, it's three 3.6V cells (~3.97V). Here's the circuit inside the battery: https://dl.dropboxusercontent.com/u/15526481/Permanent/EEVBlog/IMG_3340.JPG

And here's the underside: https://dl.dropboxusercontent.com/u/15526481/Permanent/EEVBlog/IMG_3333.JPG

[amyk]

I see NTC (thermistor) and the two main terminals, but sadly the other 3 don't look like they're for balancing... one is for the thermistor and the other looks like it goes through two resistors. You'll have to trace out the schematic.

[M. András]

there is only 2 terminal on the charger too apart from the main power terminals. the small ones marked as t and c1 fitted on the charger only, 1 wire interface? or what?

[John Harwood]

Your schematic and the other link you posted are showing up as "File Not Found"... Will you please re-post them? Thanking you in advance. Regards, John.