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Old 05-05-2012, 05:09 PM   #292 (permalink)
steffen707
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Join Date: Oct 2009
Location: Midwest
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Quote:
Originally Posted by Daox View Post
I thought I'd give an update on this thread. I've been using the PHEV kit consistently since about April. I haven't gone through many tanks of gas since then (only 5, yay), but the performance of the kit has been pretty good. Without the kit I normally average about 55 mpg in summer and 45 mpg in winter. The first full tank with the kit I didn't keep track of kWh used, and I was getting used to it and figuring out how to best use it. I got 64 mpg. By the second tank I had gotten the hang of it and kept track of my kWh used. Actual mpg was a very nice 79.0, and mpge was 65.3. That was my best tank for the season as most of the other tanks had more long distance driving where the PHEV kit couldn't be used as much since it has ~40 mile range. Now that it is working well with my custom BMS, I am very happy with the setup. I love EV mode and use it every day going to work and back.

I am pulling the kit out one more time though. I have a few weak batteries due to the abuse from the crappy stock BMS. I'll be returning them for new ones under warranty as my warranty is up at the end of this month. I'm confident that it'll last a long time once I get fresh batteries in it. I'm not deep cycling them at all during the daily commute, and I'm also limiting the max charge to about 80% to increase their life. I currently have no low voltage/low charge cutoff. However, I'll be adding an LED that lights up when the low voltage alarm on the celllogs goes off since I can't hear the alarms while driving. Unfortunately this can't be used to automatically shut down the PHEV kit due to issues with voltage sag variation. I may eventually add some sort of amp hour logging to automate some sort of low side cutoff, but its not really an issue for me 90% of the time since I only commute 15 miles a day. I will also be adding an ammeter on the output of the PHEV kit to show how much power its putting out. The SGII will show the OEM pack's in/out power use, but it doesn't really give an accurate picture of what the PHEV kit is actually doing.
I'm looking at buying a used prius and want to get a kit like the enginer, but after reading this whole thread, i'm kinda scared of having all these part failures as you've experienced. Was most of this due to the crappy BMS that your enginer kit came with? Do the new enginer kits come with a good BMS that you don't have to worry about and monitor so much?
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