Join Date: Oct 2008
Location: Moncton, NB, Canada
RC type LIPO is typically 4.20v~3.0v per cell charged/drained ..
Lifepo4 cells are 3.65v~2.0v per cell ......
Lead acid 12v bricks ( 6x 2v cells in one brick ) generally sit at 12.8v charged and no load...
In order to parallel batteries, you need to combine the proper number of cells so that they operate in the same range.
so. 4x lifepo4 cells in series = 3.65v x 4 = 14.6v .... and once off the charger and put under light load, most of them drop to 3.3~3.2v range x4 = 13.2v ~ 12.8v .. .fairly close voltage range to run with SLA in parallel.
Lipo on the other hand.. 3 cells x 4.2v = 12.6v .. hook that up to a 12v SLA and the SLA will over-volt the lipo = BOOM
4 cell lipo x 4.2v = 16.8v .. with a 12v SLA .. will cause a serious over-volting of the SLA brick .. again = BOOM..
so. bottom line.. if you need more range, and already have an SLA pack... get any Lithium pack you want that can deliver the power you need.. and run A pack.. then the B pack.. do not parallel them....