Thinking of creating a DIY PHEV

You have to keep reading a lot more......
Through the years, conversions had evolved many times, I think it had already going all the way around, "re-inventing" the same all over again.
Depending in what type of PHEV configuration conversion, there is NOT a relay paralleling the stock NiMH.
My former 2004 now 2008 went trough 3 different types and ended with , under my criteria, the best of the crop.
Still working with out a problem, I was the flag ship for Hybrid Interfaces "Plus" series 5 years ago.
Toyota took the same approach on their newest PiP, augmenting the traction battery for a much larger one, better control of SOC and battery depletion use and a tweaked software.

 

No, some (most?) of the conversions allow the inverter to charge the add-on pack, too.

Maybe you are thinking of the Enginer system, which doesn't allow you to charge up the add-on pack. But that is because of the DC-DC converter method it uses.

The main concern I suppose would be that your add-on pack can handle the large regen currents (100A+)

 

I would like to jump in here since this thread seems to be releivent to my own train of thought and I won't be the only Newbie here.
I, too want to utilize several of the OEM Gen2 batteries in my salvaged 2007 Gen2. Here is some of my reasonings:
1) I managed to get a good deal on a second battery (when I thought my origianal was bad, not so!). And I expect I will be able to get another when I purchase a parts car for other Prius repairs in my shop.
2) Plug in charging isn't on the top of my list but should be available so I will deal with at as a seperate issue, eventually.
3) My primary objective it to extend the range of EV and more effective use of Blended Mod with the ICE augmenting the electric rather than the OEM method. My observation in driving my Gen1 is the traction battery stays at or very near 99% and when ever there is a Regen opportunity, there is now where to store that energy. (lack of battery capacity). So there must be a BMS that will offer this effectively. Similarly, the majority of my driving is beyond the range of EV, both in speed and distance. So, any BMS that doe offer ICE charging enroute, along with Regen is going to be my choice. (too be honest, why carry around a 1/4 ton of batteries and hardware that are of no use once you reach the end of you EV range.) I'm willing to compromise my ECO spirit so I can continue driving to my destination, rather that stop every 75 miles, wait 1+hr for at a charging station.

What do I expect, as far as benefits. 75-100 mpg would work. Right now I get 48 at best in my Gen1 and that might be fine, however. I have a $800 1991 Geo Metro XFI that will get me 50-60 mpg in traffic or at 70 mph. I do expect this Gen2 to do that good but hope to achieve the above objectives and see that 75 mpg with unlimited range.

Steve

 

Firstflight, you may want to join the Eastern Electric Vehicle Club as their members should be able to answer your questions & provide guidance. Their website is Eastern Electric Vehicle Club Website

 

Here is one that could do the job.

Amico ZP300A 200V-2200V 300A Stud Version Rectifier Diode with Heatsink - Amazon.com

You would also need a charger to recharge the add-on battery.

JeffD

 

If your going to parallel the stock NiMH pack(s) as I want to do, how much of the BMS, monitoring and control could one utilize in this scheme??
I my recent experience, I purchased every thing on the pack mounting/enclosure. (the seller was afraid to touch anything inside and I had to disconnect the power leads, after pulling the Safety Interlock and tested to ensure that power was off.) I even took the vent ducting and forgot the cooling blower.

Steve

 

Steve,

The Prius BMS is only a monitoring and reporting system and the battery ECU reports results on the CAN bus:

• Module pair voltages & series resistance
• Battery SOC
• Battery temperature at several points.

The fact that a Prius never takes the HV battery much below 40% SOC means that a diode-connected aux battery will only discharge to that point as well and will not be discharging whenever the original HV battery is being charged. This will protect the aux battery from being over utilized.

A real BMS would also help maintain battery balance and in your intended use, this becomes important. Doing this at the module pair level would be a minor adaptation of a 12v lead acid BMS, and doing it at the Module level would be an adaptation of a BMS for 8v lead acid batteries.

You will need to provide cooling if you pull high currents from the extra battery or while charging it.

JeffD

 

What's the best way to follow in your footsteps and do our own conversion for our own Gen2 cars for the lowest price possible? Maybe a list of links? Or a specific thread that has the most info?