Yes, but what voltage do big "garage" jump starters deliver? My guess remains that it's not that high but they have enough internal oomph to supply a big current without dropping the voltage. I assume that the electronics can't handle the very high currents of a jump start battery, which is much higher than a charger or alternator output, so the issue is the current, not the voltage. The high current may damage the internal circuitry of a lithium battery, whereas the lead in a lead acid battery can take quite a beating, as there are no electronics to be damaged. but ... it's not the high current that's the issue, that would never go through the battery, it's the (possibly) high voltage from the jump starter which is the problem. Does anyone know of advice from the battery manufacturers or recovery organisations on jump-starting? Jonathan