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

[Daox]

Originally Posted by hybriddriveguy

They do not consider these balanced until the are all within .002 of each other. These lithium do react totally different than any other chemistry I have worked with. It is almost like having 16 picky eaters sitting there and trying to get them all to agree on a common meal. The best solution will be to set up a charger that charges each cell based upon it's own needs or go through the long process of balancing with the stock unit. We were getting close on ours a couple weeks ago and lost another dc/dc.
I am working on a charger upgrade now.

Like I said though, I let the balancers run overnight. They were actually done balancing before I went to sleep, but I didn't have enough time to charge so I just let it sit.

After break in, do these cells tend to smooth out and become not picky?

I agree the best solution is individual chargers, but as you said the price is prohibitive.

[mrbigh]

Remember, you have to cycle the batteries by charge and discharge cycles

[Daox]

Yes, I am planning on doing that. I gotta be able to charge them to do that though.

[mrbigh]

Daox, Eric Powers (also know as "ericbecky") has experience in this kit, so far I know, he owns one for his Insight and may be another people from the same area owning these Enginer kits.
They are part of the Madison Hybrid group but I do not know if you participate with them.

[Daox]

Jack got back to me this morning on the charger. He thinks its not bad, but the charger is adjusted to turn off while the pack voltage is still on the low side. Asking for more info now... He says there is some adjustment pot on it. I didn't see it and I had the end covers off of it this weekend already.

[hybriddriveguy]

Yes, they will stay balanced once you get them there. The trick is for them to stay balanced while charging and discharging. Having a static balance, although it is nice, will not always mean they will stay that way when charging or discharging. We are looking for a balance while charging or under load. I had all mine balanced below .001 and connected the charger and within an hour had one cell over 4.25 while others had not risen above 3.20.
Fortunately, I was watching it and caught it right at the moment that one cell jumped from 3.79 to 4.25 and shut things down. It appears 3.70 is about max on these cells without bad things happening.

Just to give me a number to work with, what would any of you with this kit be willing to invest in a well built charger that regulates the cells individually?
This will let me know whether it will be a project for my kit only or something I could maybe buy the parts in quantity and supply them for sell to other owners.

[Daox]

Over time do you see these cells stop being so picky, or do they always stay this way?

I recommend you start your own thread on your charger topic.

[rgathright]

Originally Posted by hybriddriveguy

Yes, they will stay balanced once you get them there. The trick is for them to stay balanced while charging and discharging. Having a static balance, although it is nice, will not always mean they will stay that way when charging or discharging. We are looking for a balance while charging or under load. I had all mine balanced below .001 and connected the charger and within an hour had one cell over 4.25 while others had not risen above 3.20.
Fortunately, I was watching it and caught it right at the moment that one cell jumped from 3.79 to 4.25 and shut things down. It appears 3.70 is about max on these cells without bad things happening.

Just to give me a number to work with, what would any of you with this kit be willing to invest in a well built charger that regulates the cells individually?
This will let me know whether it will be a project for my kit only or something I could maybe buy the parts in quantity and supply them for sell to other owners.

Thanks for your help here.

Do you have any estimates for how far you can travel with the 8Kw pack?

Could an 10Kw system be possible and still allow 4 passengers?

[mrbigh]

In this case, what's the advantage of buying an "inexpensive" KIT of this kind that is showing so many disadvantages.
If I were you, I will buy the empty case, better batteries than the Motcell and the no name brand DC-DC converter and expend serious money in a decent Battery Management System that will furnish an extended battery assembly life and a very well made charger.
Of course, we are talking already to an almost 3 times the price of the current promotional Enginer kit.
I'm no bashing the Enginer products, but you have to look at what you had purchase, a very basic kit.
The products that I have sold and installed, were meticulously checked for functionality and operation as part of my professional install charges; any modules I found out of spec's were exchanged.

[Daox]

Guys, keep the charger talk out of this thread please.

I just got a reply from Jack again. I need to take apart the charger and adjust the potentiometer inside it to increase the charger shut off voltage.