i have built a small portable power pack (4s6p 18650 with a 10A BMS charger for each 4s2p block) with about 180Wh for a camping trip. build log will follow. i want to attach 2 power tool batteries to the pack (Einhell Power X Change 5ah 18V) too add additional capacity. i want to be able to charge the pack from the power tool batteries i plan to use the external batteries in parallel but I want to be able to put in batteries of different charge level and capacity eg a full 5ah and a empty 1 ah side by side without over charging the 1A.
the pack runs of a 14.8v nominal bus with dc dc converters branching of for different outputs (regulated 5v 6.4v and 12v) mode selection is done by a 3 way switch from the battery pos 1 connects the battery to the charging port (24V input) pos 2 is the off position and pos 3 connects the battery to the main power bus = on.
would it be possible to charge the external batteries too by adding some more dc dc converter backwards. with the same selector switch for each external battery as the main battery has
i do not know what the einhell batteries need as a charger but i will investigate further.
for reference Einhell = ozito in GB and australia
best regards Albach
the pack runs of a 14.8v nominal bus with dc dc converters branching of for different outputs (regulated 5v 6.4v and 12v) mode selection is done by a 3 way switch from the battery pos 1 connects the battery to the charging port (24V input) pos 2 is the off position and pos 3 connects the battery to the main power bus = on.
would it be possible to charge the external batteries too by adding some more dc dc converter backwards. with the same selector switch for each external battery as the main battery has
i do not know what the einhell batteries need as a charger but i will investigate further.
for reference Einhell = ozito in GB and australia
best regards Albach