how to combine a ryobi battery with a bosch charger ?

September 10, 2012 8:55 PM

what is the pin output of the bosch charger AL 1411 DV. one is obviously marked positive, so i need to know which is the negative ?

i have a ryobi cordless drill, 14.4V battery 130224024, with a defunct charger, and a Bosch AL 1411DV charger. I figure they must be compatible :)

the battery pack has three pins, + and - are opposite each other, and the third (at the apex) is internally attached to a monitoring thingy (
i assume all battery packs would use similar thermal monitoring.)

i'm just wondering whether the bosch pin arrangement is similar with positive and negative opposite.

so, anyone know of any reason why i shouldn't combine the two, or the pin output of the bosch ??

thanks.





charger manual. http://www.scribd.com/doc/60568372/Bosch-Charger

posted by captain wibbly to Sports, Hobbies, & Recreation (3 answers total)

i assume all battery packs would use similar thermal monitoring.)

I would guess that, for the same battery chemistry and behavior, electrical engineers sometimes use the same family of chips and associated signaling set up.

And sometimes not.

Here's a somewhat banal video of a lithium ion battery burning.

And a nice place to buy safety glasses.
posted by sebastienbailard at 11:40 PM on September 10, 2012

inside the ryobi battery pack next to the cells, connected to the third pin (and -ve) appears to be a small thingy which i'm guessing is a thermostat thingy :)

i'm guessing this as a thermostat thingy as from my previous googling, thermal monitoring seems an important tool in quick charging of nicads...
posted by captain wibbly at 9:41 PM on September 11, 2012

It would probably be a thermocouple or thermistor, I guess.

Or a "thermal cut-off switch". I don't have enough experience with this stuff.

http://www.electronicspoint.com/ptc-thermistor-nicad-battery-pack-t110588.html

In your shoes, I'd dissect a bosch and a ryobi battery pack and verify that each uses the same widget like a thermal cutoff switch, with the same specs, plugging the widget into digikey. Along with probing quite a bit with a multimeter.

I strongly suggest picking up another drill or cordless screwdriver from the same family of tools/batteries. Maybe even a used place or craigslist if you're just after the charger that accompanies it.

I'm sorry if I was quite so dismissive earlier. I don't think a mains-power appliance like a battery charger is a good first project to learn on, if you want to pick up electrical skills. Because the failure mode is 'pumping 120V AC into something broken', and battery chargers are supposed to behave themselves while unmonitored in another room.

Instead, I'd pick up "Electronics for Inventors", and an arduino or rc-vehicle kit, and then go to a local hackerspace.
posted by sebastienbailard at 10:54 PM on September 11, 2012