I have used two high power chargers very reliably. The Hyperion super Duo and the PowerLab 8 or 6. For these higher power chargers you do need to look at a 24v PSU though. Ideally anything dual channel over 300w per side or parallel charger over 700-700w will do nicely. If you have a cellpro 10s though it might be cheaper to just get a second one of those with the FRA discount through optiPower.