pepsis2

ride bicycles la.. if u really wanna go green ... or take buses (i regret but realize that the public transport sys in Van just sXXks!)

cyberstudio

The hybrid battery is basically NiMH batteries - same technology as the ones you use in old cellular phones.

Lead-acid batteries (the usual car battery for starting and powering 12V devices) are not used because they have low efficiency. You want almost all the charge in the batteries to be usable for moving the car, so it has to be NiMH.

If a lead acid battery is depleted (or even just not fully charged), its life shortens. NiMH retains its capacity even when it is fully depleted.

A lot of these are put in series to give several hundred volts. As with all things NiMH has a finite lifespan. To increase the life of the battery Toyota keeps the battery only 60% charged at a maximum. If the battery is overcharged, the battery will start giving out the extra energy as heat, and battery life is much shortened.

How to detect charge percentage? It is not easy and complex algorithms are required. As with all complicated stuff, a slight error may trigger malfunction.

It is the battery that fails in a hybrid and it is expensive to replace. People know this and this dealership is handling the issue very inappropriately. If this is just a rare one-off occurence, I am sure Toyota would rather just pay up the cost instead of having its reputation tarnished by the media like this.