2nd Nimh battery pack

you can nog overrev the car because you add one pack..
the inverter will limit the current and voltage and the prius ECu;s will do its job. if you add 100 packs or just 1.

NimH packs go well toghter you just have to level them off.
and dont put a high 230 volt pack connected to a 200volt pack
then you will have high discharge into the 200v pack.

not just Hymotion

This guy is a EE so look at CAN-view index

 

I had been one of the PHEV pioneers in the USA and driving my conversion since Dec 2006.
I went through some different PHEV types and prototypes through this time and since a while now, I have my extra electrical storage with 3 add on packs, OEM Prius NiMh .
Your electric range is depending on how much money you want to expend and add on weight for total efficiency of the conversion.
This are NOT toys to play for everyone and some cat lovers are not the right ones for advise in your particular technical question.

 

And to reiterate what MrBigh just said:

It's not for the faint hearted. Just adding an additional pack and then going down a long hill using regen without properly checking the health of the pack can leave you with nasty consequences...

Without correct battery monitoring, cooling or charging then nasty things can happen. Believe me, I found out the hard way while trying to cut corners in my PHEV conversion.



If you follow all the wisdom and knowledge of the pioneers, and you understand fully what you're doing (and it's not quite as simple as it may first seem) you can end up with some fantastic results... especially if you use a charger and go for a full PHEV option.

But again, it's not the sort of thing you do unless you really have some experience in high power EV packs....

 

That is one very nasty picture!

 

And it was one nasty battery in reality. Luckily I was still able to recycle it at the local recycling depot.

The smell it gave off was terrible... and even now my car still smells of exploded battery.

 

Hi Toyotecwv,

Probably the easiet way to do this is to add wheel motors to the rear two wheels, and run the additional battery pack as an independant system. It can be recharged thru-the-road, and provide an extra 30 hp on accelleration if done right. The advantage of this method is its independant of the existing Prius system. So, if you screw up, no problem. This does not alieviate you of having to learn some computer and electrical engineering, but as you learn along the way, the stock car stays intact.

 

There needs to be a clear distinction between an unsafe modification and an unproductive modification. In most cars, these are fairly straightforward to identify. In the Prius is where these two are deeply interwoven.

Most single-individual efforts are looking for a productive modification, not even being aware of the safety margins orginally engineered into the design. Unfortunately, the result is a lot of bragging about how they have "improved" the car with no idea of what has been sacrificed.

 

Just to put my comment at the top there in context, I was responding to someone who was talking about hotting up a prius, changing the engine and adding a battery pack. I totally agree with FL above and would love to source a pair of pancake motors.

 

Sorry that was Donee above but sadly FL is probably right first.

 

Evan,

I've been away from PriusChat for (seems like forever) quite awhile.

I completed my PHEV conversion a couple months ago, after a great many problems.

Last September, the first step was the addition of a 2nd NiMH pack in parallel with the first.

The two likely mistakes are failing to run the current from all batteries through the current sensor (see CalCars description of how this is done) and the second is failing to be certain the added battery gets adequate cooling. Convective cooling is sufficient, but there must be air space below the added battery (or batteries) for that to occur.

A third (non-serious) mistake is forgetting to push down on the lever on the service plug grip to engage the ECU electronics after replacing it.

The certainty of a 2nd battery pack giving improved mileage is IMHO questionable, because of difficulty in repetition of precise conditions for different runs. It's too easy for something as simple as different weather conditions to produce a 5 to 10% difference. My first test doing this convinced me that I did get significant improvement, but since then I decided that the results weren't consistent enough to be conclusive.

In theory, extra batteries should reduce energy losses, since parallel batteries have less internal resistance. Three in parallel should only lose 1/3 the energy of a single pack under the same acceleration or deceleration conditions. However, there's speculation that the added weight offsets the improvement. This may depend on how many hills are involved. In my case I have about 180 ft of elevation changes in just driving a closed loop around Cheney (a total distance of about 5 miles).

Overall, my total conversion took about 6 months and would have been a lot less if certain mishaps hadn't occurred. Eventually, I'll document what went wrong (hopefully why).

For now I'll say:

1) I'm using reclaimed battery packs from wrecked Prii obtained from AutoBeYours.
2) I'm using Norm's BMS+.
3) On my first successful EV run I got 18.46 miles without the ICE coming on. Since then I get about 15 miles, but have turned down the adjustment for the target voltage to reduce risk of overheating.
If I never left Cheney, I could drive two or three days on a single charge.
4) Driving under the control of the BMS+, I can get 100+ mpg for 30 miles, but have never managed a round trip from Cheney to Spokane in less than 40 miles, by which time the mpg is down to 90.
The elevation change to Spokane is about 500 ft (downhill to Spokane).

When I get all the mishaps documented, I'll post here.

Dave M.

 

hoop to se you docs