Ennocar / Ennopro replacement prismatic modules

The original batteries aren’t a Panasonic product. They are made by Primearth EV Energy Co., Ltd. (PEVE), a joint venture of Toyota (80.5%) and Panasonic (19.5%).

There is a web page with basic product characteristics, but I was surprised to see even this much. Like many automotive suppliers, PEVE sells only to automakers, not to distributors or end users, so there is no need to publish detailed product information, which may also be proprietary to their customers.

The Toyota part number for a replacement HV battery assembly is G9510-47031; see catalog Figure 82-01, Battery & Battery Cable. Regarding the modules, Toyota writes (note N03, image 3), “This part is not supplied as an individual part, because it is difficult to keep the function/quality of parts assembled/disassembled.”

 

I realize this thread is a few years old but I stumbled across it and I can answer this question. I bought a EnnoCar Ni-MH 202V 6.5Ah Steel Prismatic Hybrid Battery for Toyota Prius Gen2 2004-2009. Total was $1,191.30. I paid extra for the only option that was available which was a discharge rate of 45C instead of 30C which was supposed to be better. After shipping and Paypal fees it came out to $1,829.59. I was fine with it as it was better than the $3500+ I had heard Toyota dealers were charging.

Immediately after installation, my hybrid guy who installed it said that it wasn't charging all the way, so I drove it around the block and sure enough, it would stop charging when the bars reached about halfway. Tests revealed later that day that it would stop charging when it reached 60% charge. Also, C1259 & C1310, along with 4-6 extra "module becomes weak" codes. I contacted the Ennocar rep and after I uploaded a video of Dr. Prius data (while the car is running), the reply from the Ennocar tech guy was to check the installation to make sure it has proper insulation. This didn't sound right. Lithium Ions you want to insulate because they actually work better with heat, but NMH is the opposite and those need cooling, not insulation.

I told Ennocar that a refund was in order, but I would first try driving it for a week and see if the problem went away on its own. After all, this was a brand new battery pack. So, during the week I drove it, the triangle of death would come on and the ECU would disengage or shut down the hybrid system leaving the ICE with the whole workload resulting in a car with very very poor acceleration, but I found that if I shut the car off, when I turned it back on, the hybrid system would be working again (if only temporary).

I couldn't come up with the $600 and after 2 months I really needed my car so I put the battery back in, and have been driving it with the code reader permanently connected so I can clear the triangle of death every other stoplight and get 19 mpg. I can get around town like this but can't go long distances or on the freeway. The only difference after reinstalling was that it appeared to now have the normal charging capacity with all the bars but still had the trouble codes. I recently found that I can get a new OEM replacement battery pack from the Toyota dealer for $2900. I wish I would have done that instead.

 

Heat is a killer for Lithium Ion. It is not a good thing.

 

If your 'hybrid guy' was concerned that it was faulty due the car ceasing the charge at 60%, I would have little faith in anything else he had to say. If he's the one that built the battery with your new modules, it may warrant a review of the build quality.

I have no idea of the quality of the modules you purchased, but they could easily be tested by a real 'hybrid guy'.

You would have been much better off purchasing a NiMH battery from a wrecked Gen4 and using those modules to rebuild your battery. Kind of like buying a new flashlight at Lowe's and then removing the D cells from it so you can install them in your favorite flashlight.

 

Ok, then which batteries are the ones that love heat? I know I read about it..

 

I know I know - the worst part about it is the original battery had 249,000 miles and when I was about to embark on a 3500 mile drive I made the correct decision to replace the hybrid battery pack. I took it to a place in LA and the guy tested the battery and actually talked me out of replacing it, saying it was fine. I drove the 3500 miles to Merida, Yucatan (where I now live), and a week later the HV battery goes. But now I'm not in LA anymore and Merida certainly is not the hybrid-guy capital of the world! I should not have bought one from China where it costs me $600 to ship it back for a refund but where I'm at there is no access to aftermarket HV batteries. I thought Toyota would be insane so I never checked until after the fact. Come to find they sell them for $2900 which is not bad at all and really the only way to go. I don't believe any aftermarket battery can come close to the OEM. So, Could it really be the build quality? And why did the Ennocar tech say it had to be properly insulated? It gets over 100 degrees here - I don't see how insulating it would be a good thing...

 

None used in EVs that I know of.

In fact the single biggest life killing problem with Litium cells is thermal management during charge discharge cycles. The best situation for the cells is a constant temp not too hot and not too cold. There is so called Phase Change Material technology to manage thermal excursions. They are used in smaller applications like electric bicycle batteries.