Can I charge my battery with a DC 12v to DC 48v step up converter?

stormin

New Member
Region
Canada
Hi all,
Does anyone know if the following DC 12v to DC 48v converter would charge my ebike 48v batteries when connected to my 220Ah house batteries.
This converter outputs about 48v, instead of my AC charger which outputs 54v. Is the 48v enought to charge?
Thanks.
 

mschwett

Well-Known Member
Region
USA
The ebike battery is a lithium 48v x 14Ah. Is the 48v output enough to charge or would it just be too slow/insuficient?
a fully charged 48v eBike battery is actually 54.6v - 13 cells at 4.2v each. you’ll need a step-up to charge from lower voltage, assuming enough current…. but more to the point, battery chargers contain circuitry to vary the charging parameters as appropriate for the battery. you can’t just plug them into any random power source.

this is the specialized e-Bike subforum here, are you asking about specialized batteries? or just more generally? what kind of charger are you currently using?
 

stormin

New Member
Region
Canada
a fully charged 48v eBike battery is actually 54.6v - 13 cells at 4.2v each. you’ll need a step-up to charge from lower voltage, assuming enough current…. but more to the point, battery chargers contain circuitry to vary the charging parameters as appropriate for the battery. you can’t just plug them into any random power source.

this is the specialized e-Bike subforum here, are you asking about specialized batteries? or just more generally? what kind of charger are you currently using?
It's a regular ebike battery (Ariel Rider), my current charger is 120v, but would like to be able to charge my ebike battery occasionally when travelling/camping using my AGM batteries without the need for using the inverter (DC to AC to DC inefficiencies).
Would charging from a constant 12-13v source without the charging process going thru the various stages damage the battery, if only done occasionally?
Thanks.
 

stormin

New Member
Region
Canada
It's a regular ebike battery (Ariel Rider), my current charger is 120v, but would like to be able to charge my ebike battery occasionally when travelling/camping using my AGM batteries without the need for using the inverter (DC to AC to DC inefficiencies).
Would charging from a constant 12-13v source without the charging process going thru the various stages damage the battery, if only done occasionally?
Thanks.
Assuming I use a variable step up and increase the output voltage to 54.6
 

theemartymac

Well-Known Member
I'm no Rocket Surgeon, but most modern smart chargers have a ramp-down charge rate as they exceed 80%, and the last 90% charges slowly to prevent excessive heat and battery damage. If you were to charge "unregulated" to 80% or so, you would probably be OK, but the better bet on single stage charger might be to just charge at low amperage, like ~2amp the whole time. Longer charge time, but less need to have an adaptive charger.

But as mentioned, 48V is far too low to be useful, and some batteries hit the voltage cutoff as high as 46V. I would think either aiming for a slow amp charge rate to a full~54V, or setting your 'fast' charger cutoff to 51V (~80%) might both be practical options.