Charging connector for BOSCH battery question?

[solbike]

Does anyone have any experience with the charging connector (from charger to battery) for the BOSCH battery (400 Wh) from a Hai Bike? I'm asking as I have a customer wanting me to set up a solar charging system for this type of ebike. It's a typical 36V lithium ion battery but the plug has multiple connection points (for memory - as I don't have one in my shop). Most standard Li 36V battery chargers typically just have a pos and neg wire going to them but some systems have interesting mechanisms. If within this connecter there is just a pos and neg wire then it will be straight forward to charge the battery with a 36V panel and 36V regulator or else a 12V panel with a 12V - 36V DC converter but if there is something funny going on then it will be tricky and there may be a need to lose some efficiency and increase the weight by charging a 12V battery and using an inverter before going through the regular charger (a reliable but not so efficient way). If anyone has experience with the charging system of the BOSCH battery then please send me your suggestions as it will save purchasing and potentially sacrificing a charger. Thanks in advance.
Matt, Solar Bike. www.solarbike.com.au

 

[amberwolf]

Why not just use a voltmeter and check which pins are what voltage relative to each other? Or open the battery up and check / measure where the actual connections go?

 

[voicecoils]

The battery does not have live voltage you can probe with a multimeter, I tried. I think the charger & battery must do a digital handshake before the 36v DC connections go live.

Simplest solar charge option will be to use an inverter so the standard Bosch charger can be used even though you'll loose some efficiency.

 

[amberwolf]

If there's no output on the battery at all on any pin until it gets a digital signal from an external source, then it could not power the bike, unless the bike has a separate battery to operate electronics on it that also do what teh charger would do.

It is a lot more likley that it's just a "fuse" signal, so that one or more likley a pair of the other wires in the multipin connector is meant to connect to other pins in it.


It might not be a direct connect, having to go thru a resistor of a specific value, but it is much more likely it's just a direct short jumper.

But to find out, you'd have to open up teh pack and trace out the wiring from the connector pins to the stuff inside the pack.

I would guess there are four "active" pins on it, one for pack + and one for pack -, and two others. If you find the wires that go to + and -, which will probably be a lot thicker than the others, then I would bet you can just short the other pair, and it would enable the pack's output.


Alternately, if you have the bike it goes to, just measure the resistance between each of the pins to the rest of the pins in the bike-side connector, without the pack attached. Whichever one reads a short is the pair of pns to short on the pack connector to get access to the pack voltage.


It *could* be more complicated than that, but I doubt it.

 

[voicecoils]

The system does have a separate battery, a USB rechargeable one in the head unit. But it could well be a 'fuse' signal like AW suggests. I haven't seen one of the batteries apart in person.

A few photos and some info here (using Google Translate):
http://www.pedelecforum.de/forum/index.php?threads/infos-über-bosch-antrieb-can-bus-daten-usw.17799/

 

[solbike]

Thanks for the suggestions. My main problem is I don't have the components in front of me - and chargers for these bikes are $200 to $300 so I want to avoid purchasing initially if possible. For memory, I thought there were 4 pins but from a picture it looks like there are just three - http://www.bosch-ebike.de/media/alle_bilder/produkte_1/charger_2/Charger_Active_P2.jpg?width=7016&height=2918
I'm guessing that one must be for the "handshake" and the others the +ve and -ve. It seems that I'll have to get a charger and battery to test things with of course but assuming that I can identify these what would be the best way to short circuit the "handshake/fuse" third pin?

Thanks in advance.