do you need a 48v charger for a 48v battery?

electricbike · #1 11-11-2007

When i upgrade my mx500 to 48v,will i need a new 48v charger or can i keep my old one?

Phil_G · #2 11-14-2007

Seems to be no-one around at the mo so I'll answer this one...

There are several ways of charging your batteries, the first is to be preferred:

1) buy a new 48 volt one with a similar specification for charge current as your 36v one
2) disconnect all 4 batteries, then parallel connect them for the duration of the charge, and use a high-current 12 volt car battery charger.
3) break your four batteries into two packs of two, ie 24 volts each, Parallel them for the charge and use a 24 volt charger.
4) Buy a dumb 13.8 volt power supply which MUST have an isolated output, ie neither pos or neg are connected to ground, and wire this in series with the output of your 36 volt charger. Choose one that gives at least as much current as your 36v one. More is ok, the 36v one will limit the current.
5) wire a charged leisure battery in series with the output of your 36 volt charger. Make sure you dont discharge it anywhere near fully though.

Cheers

Phil

PS given the nature of the question, maybe I'd better emphasise that in adding a psu or battery in series with the existing charger, you're wiring charger neg to bike neg, charger pos to psu neg, psu pos to bike pos. Dont get it wrong!

electricbike · #3 11-14-2007

Quote:

Originally Posted by Phil_G

Seems to be no-one around at the mo so I'll answer this one...

There are several ways of charging your batteries, the first is to be preferred:

1) buy a new 48 volt one with a similar specification for charge current as your 36v one
2) disconnect all 4 batteries, then parallel connect them for the duration of the charge, and use a high-current 12 volt car battery charger.
3) break your four batteries into two packs of two, ie 24 volts each, Parallel them for the charge and use a 24 volt charger.
4) Buy a dumb 13.8 volt power supply which MUST have an isolated output, ie neither pos or neg are connected to ground, and wire this in series with the output of your 36 volt charger. Choose one that gives at least as much current as your 36v one. More is ok, the 36v one will limit the current.
5) wire a charged leisure battery in series with the output of your 36 volt charger. Make sure you dont discharge it anywhere near fully though.

Cheers

Phil

PS given the nature of the question, maybe I'd better emphasise that in adding a psu or battery in series with the existing charger, you're wiring charger neg to bike neg, charger pos to psu neg, psu pos to bike pos. Dont get it wrong!

cool! thanks for the advice