[HPEVS]

Thanks for bringing that up JRP3. Our Scion has the Calb batteries in it, I will have to run a trace and take a look. We have primarily worked with the Voltronix in the past.

[ricklearned]

Originally Posted by HPEVS

Thanks for bringing that up JRP3. Our Scion has the Calb batteries in it, I will have to run a trace and take a look. We have primarily worked with the Voltronix in the past.

Is that the Scion that has the new controller? When I picked up my motor a few weeks ago you told me Bill was having a lot fun testing it. I won't say in a public forum the speed you told me he was getting out of the Scion, but if I was going that fast I would be looking in my rear view mirror a lot. LOL

[Ziggythewiz]

If you're going fast enough you don't need to look behind.

[DIYguy]

Originally Posted by JRP3

CALB cells use lower voltages and they don't recommend going above 3.6V, and there is an obvious beginning of the knee above 3.4V. I've been using an average 3.41V per cell at 20 amps for my 36 CALB 100's for the last three years with no issues. Occasionally I'll charge a bit higher to 3.45 if I want to maximize range.

+1 here. I charge my CALB's to 3.45 and get enough in them to call them full.

I've heard several people say also how you can't tell SOC at all from voltage when inside knee at top and bottom. My experience has been that if rested for a while, and measured to 3 decimals, voltage is actually a pretty good indicator. No, not exact... but definitely not wide open.

Some good info there on the controller. Thanks for that.

[mizlplix]

I have a little concern about the 38 cells though. Keep in mind, this controller is designed for 96 volts nominal, you are running 120 now. I have had some feedback with this combination. The first problem people experience is contactor failure. The controller precharges the capacitor bank inside the controller before it closes the contractor. It closes the contactor when the capacitor voltage is with in 2 volts of the pack voltage read on pin 1 of the controller OR 1 second has expired. When you run higher voltages, it takes longer to charge the capacitors, so the 1 second timeout is in play. When the contactor pulls in and the caps are not fully charge, it can weld the contacts. You will know this has happened if you get a code 39.

Hi HPEVS: Three questions.

1-What is the maximum voltage (cell count) that this system seems to work normally? How many cells do I lose to assure normal, as intended, function?

2-Has anyone simply attached a traditional precharge resistor to assist the curtis controller to perform an adequate precharge? (I assume the 1 second time is the limiting factor.)

3-By accessing the VCL section: Could the 1 second time frame be increased to 1.5 or even 2 seconds to assure a proper precharge?

Thx, Miz

[JRP3]

Most of us run 36 cells with no problems, 120V.
The controller handles precharge and they say specifically not to add any external precharge resistors, but I guess you could try it and see what happens. My guess would be a fault.

[tomofreno]

Originally Posted by JRP3

CALB cells use lower voltages and they don't recommend going above 3.6V, and there is an obvious beginning of the knee above 3.4V. I've been using an average 3.41V per cell at 20 amps for my 36 CALB 100's for the last three years with no issues. Occasionally I'll charge a bit higher to 3.45 if I want to maximize range.

Like this:

Charge Curve.pdf

[tomofreno]

Originally Posted by HPEVS

Hey Miz,
<snip>...When the contactor pulls in and the caps are not fully charge, it can weld the contacts. You will know this has happened if you get a code 39...<snip>Thanks for listening, Brian

I get a code 39 most times I turn my ignition off, for the last 2 1/2 years, unless I turn the key really fast.

[JRP3]

Me too, was told that is normal on shut down, by HPEVS.

[mizlplix]

Thanks, guys:

My plan is to just run the 38 cells. My charger shuts off at 3.45 volts per cell.

They sit and drop a little from there. So, I am comfortable that they are not over charging....Except for one cell...It was at 3.54 after sitting. I put my load tester on it and drained it down to 3.45 to match the others. I will keep a watch on it both before and after charging.

In the short term, I will do weekly cell checks. After I am comfortable with them, I can go to monthly checks, then semi-annual.

This week, I have spent trying to design a regen control pot that works with a steering wheel paddle style lever. It is hard to package a unit that looks well.

A 5K pot hung under the column, OR a lever with a rod along the column to the pot behind the dash board, OR a halls-effect sensor behind the dash operated by a slender rod from the paddle.

Well, still working on it.

Mean time I am getting rid of my aux. Lead acid battery. I am building a brick of Headway cells. 3 strings (parallel) of 4 (in series). 13.5 volts at 30AH with a 40 amp DC/DC feeding it.