2nd Gen Prius PHEV Conversion (Enginer plug-in lithium ion battery kit)

[Daox]

I just picked up my converter and box of batteries from the Fedex store last night. Over the next week I'll start the process of balancing the entire 4kwh pack at the low end.

[epa5epa]

Originally Posted by GeneralAnarchy

That is a lot of solar watts. Do you have enough surface area on the roof of the car?

With very careful slow driving I've been getting close to 80mpg. As the weather gets warmer I'm able to go farther in EV mode. I am planning to use a 60W solar panel to help charge the PHEV kit.

The rated amount of my solar roof panels is 264w but the real charge peak is 191.5Wp ( shown on w-u meter)
The new record of my solar charge is 4.2975kwh (from June 5 to 11). So I could still use enginer kit last weekend during my charger repair peroid. The sun is strong enough in Taiwan but It's rare more than 1 week in summer without partly cloudy sky. I think it's hard to break this record.
Thanks

[Daox]

Its been a while and I am almost at the end of my first tank being able to use the PHEV for most of the tank. The best commute to work I've had is in the mid 90s for mileage with the new DC to DC converter. I can tell its been tuned to monitor its own temperature and in the morning I get a lot more juice than the afternoons with the car sitting in the sun. This makes me happy that it won't burn itself out, yet sad since I don't get quite as much power. Still, the MFD says I've averaged 64 mpg over the tank. That is substancially higher than before, although not mind blowing.

I have yet to make my automatic arduino disconnect. It is still a necessary step IMO to getting the setup to run without the annoying babysitting that needs to be done currently.

[Daox]

Woo, scratch that measly 94 mpg. 113 mpg on the way in today!

I've been experimenting and playing with how to best use the plugin kit and obviously I still have some learning to do.

[Daox]

The other day I finished up the BMS system for the enginer kit. This is the main thing that is lacking in the kit, or at least my version of it. The newer ones have a nicer BMS. Anyway, I made a quick video of it in action.

I have changed a thing or two on the schematic since it was last updated. I'll post up a new one once I get a chance to change it.

I have gone through one tank with the PHEV so far using it a fair amount of the time. The result was 63.6 mpg. Not too bad, but I'm definitely looking for more. Charging was a pain since I didn't have the BMS hooked up yet. I am charging for the first time tonight with the BMS and am loving that I don't have to check it every 15 minutes.

http://www.youtube.com/watch?v=J9SqGUH7rGc

[Daox]

Last night right before heading to bed I checked the phev kit and the carger. I noticed it had kicked itself off. I had drained it down quite a bit and was surprised that it was done already. So, I plugged it back in, watched it a few minutes and saw it turn off not nearly at a voltage where it should have. It wasn't even up to 3.5V yet. I also turned the car on and PHEV to top off the OEM pack for tomorrow morning's commute. I noticed as soon as the PHEV kit was turned on the charger turned off. These two instances lead me to believe that there is some electrical noise back there. At the first sign of an alarm, the PHEV disconnect kills power. So, I think I'm getting a voltage spike here and there that is triggering the disconnect. I'm thinking a very easy fix will just be to add a timer to the programming. This timer will ensure that the alarm has been going for 3 seconds before killing the power. That will take care of any voltage spikes.

[bwilson4web]

Your recent posting about receiving something has me confused. Just to refresh my old man's memory:

• battery pack are large format, individual cells, series voltage?
• there is a buck charger from house AC to the battery pack in the car?
• there is a separate boost charger from battery pack to cells in the car?
• battery management modules are engineer design/build or yours?

I thought I heard clicking in the video, relays on the cell banks?

You probably live in a cooler climate than Huntsville AL. Are there provisions for warming in the winter? Any over temperature provisions?

Thanks,
Bob Wilson

[Daox]

The pack is a ~54V pack. There are 32 life cells rated at 39Ah. They are in a 'buddy cell' setup where each cell is in parallel with another, and those two are in series with the next two.

There is a 15A AC charger for charging the ~4kWh of batteries. Then there is a 54 to 240V boost converter to charge the OEM pack.

The BMS is my design. Its pretty simple too. The celllogs are a purchased item and they monitor the voltage of each cell. They have a user set low and high voltage alarm. The celllog also have an alarm port so it can send a signal in my case to an arduino. When I get that alarm signal, I'm using a SSR to cut power to the AC charger. In time it will also be used to shut down the boost converter.

The clicking is a relay in the AC charger.

Currently there are no provisions for heating the kit. The only provisions for cooling are fans in the kit. The boost converter has two smaller (60mm I think) internal fans that I think always run when the kit is turned on and even after its turned off for a while. In addition there is a 120mm fan on the case that exhausts hot air. It still gets warm if the car is hot, but the dc to dc converter also reduces power output if it gets too warm.

[Daox]

I just got in from checking the charging of the pack again. I found a/the issue. For some reason my charger is suddenly cutting out at a lower voltage than before. It used to way overcharge the batteries if left alone. Now, its cutting out before any of the cells even hit 3.45V. I haven't changed anything with the charger. I have the instructions on how to fix the issue, but I'm just wondering why its happening now.

[kim88]

I have a 2001 Prius is there any PHEV conversion kits w/EV mode available for it ? Failing the availability of that I might want to convert the car to to all electric but I've never found anything even written on the subject which is strange because it seems like it would be the optimum electric car w/motor-drivetrain base to start from. There's allot of research into traction motors being built into the wheels of electric cars which if at some time in the future becomes available as a kit it might make for the simplest conversion.