24v Charger Question

[EVTodd]

I'm getting ready to purchase a cheapo charger for my sla batteries. Does anyone have a pinout of the cheap chargers found on ebay (and other sites) such as this: http://cgi.ebay.com/Battery-Charger-Electric-Scooter-Bike-24V-1-8A-3-Prong_W0QQitemZ260245319049QQihZ016QQcategoryZ11332QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

I guess I don't understand why they have 3 pins. I want to cut the stock connector off and use a Tamiya plug (2 pin) since that's what I'm currently using on my bike.

Is the 3rd pin a ground? If so what is is connected to?

 

[dogman dan]

Third pin is ground. Make sure to use a voltmeter to determine which wire is positive and which is negative. Looking at the pic on the link, maybe it just makes a grounding connection between the frame of the scooter and the body of the charger. Changing to two pin should be fine.

 

[EVTodd]

The ground wire is connected to the ground wire on the wall socket plug on the charger, if it has one.

That's part of my confusion I guess. Most of them only have 2 prong wall plugs.

 

[TylerDurden]

Sometimes only two are connected. No biggie... like dogman said, meter it and know.

 

[Link]

I've cut into two cheap Chinese chargers now, and have found that the third pin simply isn't connected to anything. I also have another charger that has a two conductor zip-cord on it, so that clearly is the same way.

Practically all smaller scooters/ebikes use a 3-pin XLR connector for the charger. Don't know how it got started, but that's how it is now. :?

 

[docnjoj]

They need the third pin for polarization. If U use cheep plugs they could be plugged in backwards. Also, they look like standard computer plugs,so they must B really cheep!
otherDoc

 

[dogman dan]

Or they just got the three pin plugs really cheap from the chinese version of Vinny. Some scooter designs may actually need it.

 

[fechter]

On Nimh or NiCd batteries, the third pin goes to the temperature sensor. On most lead acid chargers, only two pins are connected. If the charger has a grounded AC plug, it almost always connects to the negative battery pin. It's bad practice to connect the vehicle frame to the battery.

 

[Link]

On Nimh or NiCd batteries, the third pin goes to the temperature sensor. On most lead acid chargers, only two pins are connected. If the charger has a grounded AC plug, it almost always connects to the negative battery pin. It's bad practice to connect the vehicle frame to the battery.

Ah, so there is method to this madness.

And, yes, the ones I cut into were all SLA chargers. :wink: