Charging a Bosch 10.8V Li-ion - Page 1
Forum section: electronics / projects

author: TheAmmoniacal
author_rank: Unknown
timestamp: April 09, 2014, 09:03:36 am
content: 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.

author: Whales
author_rank: Super Contributor
timestamp: April 09, 2014, 11:11:47 am
content: 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.

author: amyk
author_rank: Super Contributor
timestamp: April 09, 2014, 01:34:29 pm
content: 10.8V = 3 * 3.6VYou 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.)

author: M. András
author_rank: Super Contributor
timestamp: April 09, 2014, 03:12:24 pm
content: 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

author: TheAmmoniacal
author_rank: Unknown
timestamp: April 09, 2014, 03:36:10 pm
content: 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.JPGAnd here's the underside:https://dl.dropboxusercontent.com/u/15526481/Permanent/EEVBlog/IMG_3333.JPG

author: amyk
author_rank: Super Contributor
timestamp: April 09, 2014, 08:42:33 pm
content: 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.

author: M. András
author_rank: Super Contributor
timestamp: April 09, 2014, 09:21:56 pm
content: 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?

author: John Harwood
author_rank: Newbie
timestamp: October 16, 2017, 11:05:46 am
content: 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.