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

[eximage]

Originally Posted by Daox

. The PHEV will automatically shut off once the OEM pack has reached a programmed SOC.

Is the reference to "a programed SOC", the standard Prius cut-off or a special mod?
thanks Pete

[steffen707]

Originally Posted by Daox

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?

[ericbecky]

Enginer BMS have changed drastically from the time that Daox installed his kit.
Now they have a remote head unit and data logging capability.

Also, there are plenty of 3rd party BMS's.

For $405 you can get one from Pacific EV that, like the Enginer system, does data logging. Electric Vehicle Parts --- PHEV BMS -- Simple BMS for bicycles and Enginer Plug-In Prius Kits
Don't skimp here, choose the logging version rather than the non-logging version.


It is a great alternative if you choose not to use Enginer BMS.
You can get it directly from Pacific EV and have your installer hook it up for you.

[bennelson]

I've got another friend besides Ericbecky and Doax who has an Enginer kit in his car, who I just saw the other day.

His is a relatively new Enginer kit, and he seems to have had a very good experience with it so far.

[Cobb]

I have a kit in my Insight and its been fairly trouble free. Feel free to ask away and if you are within a hunder miles or so, maybe I could visit?

I highly sugggest going with the 4 kilowatt setup as it uses the real force cells which in my case came perfectly balanced. Otherwise you need to buy a hobby charger that handles lifepo4 cells and spend a week balancing them before first use. Then of curse taking it easy the first few weeks.

I think most recently Enginer sells the kit minus the batteries so you can make your own and just need 48 volts to run it. Thats 4 deep cycle batteries in series from the auto store.

[Daox]

I'm glad to hear they finally got the bugs worked out of the kit. When its working its great to run.

[Cobb]

Yeah, it makes the newer Insight way more drivable. I have you tube videos where I dog it and the SOC stays at 90% and it will assist as long as I have my foot on the throttle. EV mode is still limited as it does suck the battery down faster than it can recharge it.

Ive been on the fence about buying a second converter to help with the load of using EV mode to allow extended use. Ive read a lot of horror stories and was going to go this route or a Fit turbo charger. I am glad I went this route and its been trouble free.

FYI, to enter EV mode on the newer Insight get car above 12mph, then release the throttle and apply just enough pressure to remove the slack. You should see the MID show regen, then nutral or coasting, then a slight bit more pressure you see the battery only feeding the car. Its best for extending your coasting and speeds up to 50mph.

[Daox]

A small update here. I've recently been working on rebuilding my PHEV kit since I had some issues with it (caused by yours truely, no fault to Enginer) and blew up two cells a couple months back.

One step of this rebuild is evaluating every single cell in the PHEV kit's pack. The pack is made up of 32 "39Ah" Mottcell cells. The configuration is 16 in series, 2 in parallel. I've been using a Revolectrix PowerLab 6 charger to evaluate each cell. The process charges each cell up to 3.625V at 38A (~1C), then discharges it (I forget what voltage, I think its around 2.8V) at 38A, and then recharges it. The charger datalogs a bunch of data and tells you the Ah capacity in and out. The Mottcell cells I've found with this cycling setup only give a max of 34Ah of capacity. This is from brand new unused cells. Some of my older used (and abused) cells are showing capacities of around 30Ah. This is quite disappointing to see that you don't even have the rated capacity. But, its what I have to work with and it'll have to do.

The second step of the rebuild is to get the BMS' discharge protection put together and working correctly. This is the main reason I had the cells explode on me. I had overdischarged the pack and disconnected the BMS to get the charger to start charging things. I forgot to reconnect the BMS which provides charging protection and my two weak cells got overcharged. The next morning I found the mess. But, this emphasized the need for a fully functional BMS system. So, I will be working on assembling and getting the discharge protection working on the BMS. My thread for info on the BMS is here:

http://ecomodder.com/forum/showthrea...bms-20445.html

[bennelson]

Are you going to show everybody the photographs of your back window?

[Daox]

Haha, no I wasn't planning on posting images of the cylindrical hole in my rear windshield. Yeah, the cell actually shot right through it when it overheated and shot off like a rocket. This happened right around the time of the Fisker Karma fire and I figure EVs/batteries have enough bad press, no need to add fuel to the fire.