For my project I need voltage of 2 li-ion batteries in series. For charging them I would use this charger (one for each battery):
Could I connect those two chargers (with one battery on each charger) in series and plug them on 9/12V adapter? Or should I use 5V voltage regulator on each charger?
Another possibility would be to use 7.4V charger like this one.
I would use two identical batteries so I think batteries couldn't get unbalanced.
Could I use protection board in second link and a 8.4V adapter like this one?
Would 9V adapter be ok?