input charge voltage for 2 cell
 

i am looking to assemble my own charger, i have a circuit in mind. for a 2 cell 3200mah. i know that the nominal voltage of a 2 cell lipo is 7.4v. 1C would be 3200mah. so is the charging voltage something just a little higher than the nominal voltage? or is that as much of a concern as not going higher than the 1c rate?

the charger would be mainly for maintaining the cell, maybe around 1/10C to 1/5C for mah. a safe low current charging.

what would be a good voltage range for the charging voltage? between 7.4-10v?

actually it is a solar type charger i have in mind. i'll combine the cells to meet the needed volts and the needed mah.

when i can, i'll use my standard lipo charger for a peak charge.

any ideas?


jon

RE: input charge voltage for 2 cell
 

The charger MUST be 4.2 volts per cell. Any amperage up to 1C is OK, less just takes longer.

RE: input charge voltage for 2 cell
 

ok, it is a specific voltage.

so, if i were to charge a 2 cell it would need 8.4V, a 3 cell would be 12.6V?

just configure the charger for an output of 8.4V for a 2cell.

to keep it safe, i would keep the mah's down around 1/5c-1/10c.

thanks for that info.
jon

RE: input charge voltage for 2 cell
 

Hi Jon-

Perhaps the [link=http://www.shdesigns.org/lionchg.html]Scott Henion circuit[/link] would be helpful for you. It's an oldie but a goodie that has been built by many people.

- Jeff