Can a simple USB 3.7v 250mA or 500mA charge 2x1.2v NiCd batteries in series (2.4v)
I have a simple trimmer that has rechargeable 2x1.2v 600mA batteries hooked up in series (2.4v). The charger adaptor came with it shows spec; Input: 220-240VAC max 3.5W , Output: 4VAC 100mA (clearly 4V is DC not AC I think ?). It takes 8 or 10 hours for full recharge, I just leave it over night and forget about it..., never any problem...
I want to use this trimmer in countries with 110v, so I thought a simple solution is to get one of these USB charging cable as in photo attached. But would these with 3.7v 250 or 500mA work...?
I read that they must have auto voltage check to power off the charging otherwise it could get very hot and damage the batteries..., although these charger say they have auto switch off, but the voltage is way higher than 2.4v at around 3.7v...? Also the 250mA or 500mA could be any issues...? The original adopter was rated 100mA...!
Cheers,