Originally Posted by SPL

chris_h — The 12-volt battery in the TCH is an AGM (Absorptive Glass Mat) type. These batteries are designed to survive repeated deep discharge/recharge cycles without failure, but cannot take rapid charge or discharge without potential damage (temperature dependent). The TCH's ECU circuitry limits the charge/discharge rates. Jump starting another vehicle using the TCH's 12-V battery is likely to reduce its service life appreciably due to the very high cranking current that is drawn from it in such an operation. (It's also a rather expensive battery to replace! It incorporates both a temperature sensor and a gas venting valve and gas discharge attachment.)

Stan