adding a high voltage battery

<div class='quotetop'>QUOTE(statultra @ Nov 16 2007, 04:33 PM) [snapback]540746[/snapback]</div>

It's been done with an older Gen I Prius but I'm foggy on the details. I think the real gains came from adding additional NiMH batteries though. If I can find the link I'll post back.

 

<div class='quotetop'>QUOTE(statultra @ Nov 16 2007, 07:33 PM) [snapback]540746[/snapback]</div>

Its been done, and the benefit is minimal. Its also a lot more complicated than just hooking it up. You need to have both controllers from both packs operating, as the NimH strings each require a battery management system. Unfortunately the toyota controller babysits the batteries so much that you don;t get to use much of the extra packs capacity. You also wouldn't really get much benefit unless you could charge the pack from something other than the car. This is where most of the efficiency gain of adding more batteries comes from. Unfortunately charging the OEM battery with anything other than a Prius is very difficult. The dealers can't even do it, they have to call in a special charger from corporate. I believe there are only a couple of those in the country. You also can't just swap out the batteries with bigger ones, as the controller is calibrated for the size of the batteries.

If you take out the toyota battery, then you need to design a whole new battery management and control system as some of the commercial converters do. Almost all of the do-it-yourselfers work by adding a second larger battery in parallel with the main battery. This is usually lead (though they are now working on NimH and Lion) as its much easier to work with. They charge the big battery overnight, and then have a controller that connects and disconnects it as needed to maintain the OEM battery at the optimal state of charge for the current driving condition.

If you are interested in such things make sure you check out the EAA PHEV website, and join their mailing list.
http://www.eaa-phev.org/wiki/PriusPlus

This is the guy I know who tried the simple pack paralleling option. He is now planning to go with the PriusPlus method linked above. Incidentally this is the guy I bought my rebuilt Prius from, as have a number of PHEV home converters.
http://www.autobeyours.com/PHEV.htm

Rob

 

<div class='quotetop'>QUOTE(statultra @ Nov 17 2007, 06:42 AM) [snapback]540895[/snapback]</div>

hey boss, how is your project going? i am thinking of the same thing. does anyone know what would happen if i parallel a 216v (30amp) to the prius hv battery? do you think i will get some sort of warning light, since the voltage exceeds the stock 201.6v? thanks and i will keep everyone posted on my plug-in project.