Manually charging the hybrid battery?

[SteveO]

Sorry if this has been asked before, but I couldn't find much when I searched for it.
I know about the complete hack to install more batteries to make the Prius a full plug-in electric, but has anyone tried anything to just charge the stock hybrid battery to max capacity (full bars) while the car is parked? The reason I ask is that I'd like to start my morning commute with a fully recharged battery - and drive in EV mode as far as possible. If a plug-in adaptor is not feasible, would a battery charger (like the kind you connect to your regular 12v battery when you go on vacation) or something similar work?

Thanks,
Steve.

[galaxee]

well... there is a hybrid battery charger... but it's worth thousands (if not tens of thousands) and only regional toyota reps get them.

you're best off just letting the car charge up the battery on its own.

[Bill Merchant]

Remember, Steve, that your Prius is a close-to-zero emissions car. The coal-fired electric power plant which would supply the juice to fully charge your HV battery is decidedly NOT zero emissions. Even if you could charge the HV battery, it wouldn't be good for the planet.

[efusco]

There are several issues involved here.
The Toyota charger connects simultaneously to the HVbattery ECU and the battery and slowly charges to a nominal level (I'm not sure if it will/is capable of "topping off") for starting/running. Also, 'topping off' is not as easy/safe as it sounds.
Do you charge to the 100% SOC level? If so you will shorten the battery life.

Do you charge to the 80% level (all green bars on the MFD SOC graph)? Probably won't shorten battery life, but the problem there is finding the proper shut off point so that you don't over charge (thus the complex Toyota charger).

Finally, even if you could cheaply, cleanly, efficiently and conveniently charge up to that 80% SOC level you've only gained yourself maybe 1/2 mile (probably less) of 'stealth' over the 5-6 bar level that the Prius typicaly maintains anyway.

Those who've added additional battery power have been able to charge the auxillary batteries on the grid while the OEM battery is off-line. Thus, upon start up, the auxillary passively charge the OEM HV battery and 'fool' the HVbattery ECU once the car is in Ready mode.

I will add here (and please don't ask for details--I'm not currently at liberty to share more) that I know of at least one individual who did add additional battery packs and charged his aux batteries from the grid who required replacement of his OEM HV battery when it failed. It is not at all clear why this occured, but certainly speculation is that the combination of grid charging and additional batteries without the Toyota safeguards led to the premature demise. The SOC is held within a very tight range of SOC in normal operation to ensure prolonged battery life.