2nd Nimh battery pack

Hey Efusco,I have been looking for the same info, those links are of no help as they only disscuss there battery conversions,we both want any info that talks about adding another Toyota pack to the original pack ,what would you gain in MPG?
Thanks
Harry

 

There is no improvement in mpg by adding another Toyota pack to double the capacity because the energy to charge the packs comes from the gas. The existing pack's capacity is already optimized for FE and cost.
To improve mpg the only method is to do the conversion to a plug-in.

 

Overall expect not. Capacity != power. Since the battery's power is dependent on SOC you will extend the maximal time you can pull ~ 20 kW, but you will not exceed that power rating. Somewhere overheating is going to limit things too.

 

have a look here

http://priuschat.com/forums/prius-m...lectric-vehicle-mod-under-way-bristol-uk.html

 

If you had enough technical ability to hack the Hybrid ECU, the Battery ECU, the communication protocol and etc, you'll see 100kW(136PS) max system power plus 100km/h speed by EV only like following plug-in prototype.
Toyota Plug-in Hybrid information

Ken@Japan

 

On flat land there is absolutely no improvement, this is physics.
If he is driving in a hilly environment, the added capacity will allow longer motor assist on up hill and more regen on down hill, FE may improve.

 

The basic problem is that thousands of engineers have already "tinkered" with the Prius for many years. They haven't left you much room for improvement.

Tom

 

This is not a VW bug. These cars are not for tinkerers. There are a few mods that have been documented and are easy to make, such as the EV switch and a few others you'll find here. But start messing with the high-voltage stuff and you are into potentially lethal territory. If you are not an electrical engineer you should not even consider it. If you are an electrical engineer, chances are you won't want to. And if you had the know-how to mess with this car's electrical system, you would understand that adding another battery in parallel would extend the EV range, but not increase its power, and adding another battery in series would double the voltage and fry the entire electrical system. If you want more power, a Prius is not the car for you. It is designed for efficiency and minimum pollution, while still providing more power than any other fuel-efficient car.

Enjoy your car. Consider a professionally-installed PHEV conversion if the benefits justify the cost for you. But don't kill yourself messing with 201 volts.

Or consider buying a Tesla Roadster. You can't tinker with that one either, but it's got enough power to blow your socks off.

 

i hate seeing newbs log on to cut this down. I have long commute over highway 9 here in california.. it's a mountain road where my battery fills up on the first 25% while going down hill.. making me leave the car in B mode to maintain speed.

a new battery Would be helpful because you could force fill it.. the SOC would be "higher" after highway entries, and so forth... i would expect to hit mid 40's again with a second pack.... or additions.

if you ... really ... really wanted to.. you could change out the final gear ratios... it would reduce your top end speed but possibly make acceleration better... (while setting the prius mph record, they altered a prius with longer gears that took a tundra push start to get it up to speed..) so.. i assume a shorter final set would allow for harder accelerations?

 

btw.. have you thought about an altima hybrid.. or a fusion hybrid?

 

There are many problems with adding a second pack not least the fact that the car has been optimised for that battery and that engine. Nimh batteries do not parallel up well they have a tendancy to dump huge amounts of current into each other when you aren't looking then there are the problems of over-revving overheating everything burning up and that is just the car. You could maybe electricute yourself or wouldn't it be easier to just go for an old ford??

 

When you try to get "more" out of this car, what you are really saying is that you think you can do better than Toyota's engineers. That's a mighty extreme statement. If you can really afford to risk trashing a $25,000 car, well then, good luck! But remember that this car was designed as an integrated working whole. Everything functions together and everything is matched for optimum functionality.

If you are an electrical engineer, you can add another battery. It's been done. If you are not an EE, you really don't want to mess with high voltage. If you think it's the gas engine that's limiting the car, then you want a different hybrid car entirely, because the engine is matched to the gears to the MGs to the PSD to the software, and changing any one of those is going to be a disaster, unless you really are a better engineer than the ones at Toyota.

It's a great car. Consider HyMotion if you want plug-in. Otherwise, don't mess with it unless you can afford to risk trashing a $25,000 car.