Is 2A ok for 3 x 3100mAh batteries in series when using a hobby charger?
what brand and chemistry are the batteries?
Panasonic 3100 Li-ion
ASking cause that new Supbeam X40 supposedly charges at 2A and Im curious cause there was a german boardie who said that wasnt a good idea
I am sure other more knowledgeable blf members will chime in… but heres my 2 cents:
Charging a panasonic 3100 higher than 0.3c will reduce the life of the cell and increase the risk of something bad happening (fire/explosion)
The cell might be fine taking that current for a while, but doing so will wear on the battery considerably more than using a lower current.
If you plan on charging 3 in series with a hobby charger I would recommend even lower current just to be safe.
If the new supbeam x40 charges 3 li-ion in series at 2a - it will shred the life and longevity of the cells.
My opinion - I would avoid charging 3x panasonic 3100 li-ions in series @ 2amps
If they’re balanced using the balance tab during the charge, 2/3 C is okay.
thanks for the replies guys. I think its the usb adapter that is outputting 2A. If I use a 1A USB adaptor, that’s fine right?
I’m not quite sure how a USB adapter would be related to a hobby charger….
I Charge them at 1A with my hobby charger, in datasheet there is mentioned charged with 0.3C=0.8A.
In the charging doc stands
Charge Current
Please refer to the following change current standards by series.
NNP series Cylindrical type : 0.7 lt (or 0.3 lt for certain models) , Prismatic type : 0.7 lt. PSS and Cobalt acid series Cylindrical type : 0.7 lt , Prismatic type : 1.0 lt. (or 0
This 3100mAh version is a cylindrical nnp.
So 2A is to high, like mentioned above shorter cell life etc…
Hobby charger with USB adapter? What charger do you have?
Can’t find the datasheet from the 18650b 3400mah…
I meant for the X40. The charging line is charged using a supplied USB socket adapter that outputs 2A. So if that was swapped for a 1A adapter, it obviously charge at 1A, right?
I f a charger is supplied with 2A at 5V that are 10W.
So charging 3 cells at 10-12V, there is only less than 1A possible.
actio = reactio
or the
conservation of energy
… that got me interested, but I can’t see the image 
The charger power supply is 2 amps from a USB port. However the batteries are charged in Parallel, not in series, so the actual charging current will be
667ma maximum (2 amps/3). The X40 documentation says the actual charging rate is about 500ma, so the charging rate is fine for 18650 batteries, nowhere near the 2 amps suggested. (and yes, I own an X40)