MythBusters ask: Is efficient, low-energy, non-damaging, fast-charging of lead-acid batteries in under two hours, possible?
Charging lead-acid batteries, or any battery chemistry for that matter, is not without its limitations. In all cases the internal resistance, worse for some than others, will push the on-charge voltage to a higher level than the discharge voltage, creating, ipso facto, a round-trip energy inefficiency. Depending on the charge-discharge reactions of the electrodes and electrolyte, further inefficiencies can be incurred by spurious or parasitic secondary reactions. For example: