You need 14.2 to 14.6V (Per battery manufacturers specs) to get a full charge. 13.6 will likely negate the benefit of having spent all that money on Lipo4 batteries. Remember, that voltage has to first go to a BMS that's looking for an appropriate level to work with. Unlike older technology batts, the power doesn't just flow to the cells no matter whats feeding the battery. The BMS also needs the higher voltage to be able to activate its cell balancing mode, which is crucial to long term battery performance and life. Without the proper charge coltage, the battery will continuously degrade.
You would also need to ensure the dusulphate mode (if it has one) is disabled.
You'd be better off buying a small, 20A Lipo4 capable charger and using that to top it off.
