PHEV mod under way, Bristol, UK.

[Flying White Dutchman]

Originally Posted by aminorjourney

Aaaaah - I think they have given you only the usual data then!

You're quite right - an NG3 in standard setup will kill a NiMH battery and in a worse-case, set fire to it. However, the UK agents for Zivan have worked with the Italian head office to develop a charger profile for NiMH batteries. Unlike the standard charger profile this one will cut off the voltage at an approrpiate level to prevent overcharging and doesn't have a 'gassing' phase to the charge cycle that the normal Zivan has. It is the charger's gassing phase which is most dangerous to NiMH batteries.

As for the temperature sensor - this is actually an accessory. I don't want or need one with mine. In fact I'm going to use a external temperature sensor and microcontroller arrangement to ensure that the Zivan does not charge at high current if the battery pack temperature is too high.

More on that to follow. I hope it makes sense!


Nikki.

i have been the guy in contact with them for a long time now to get a NG3 for NIMH prismatic oem prius battery packs !

and after a while ty told me there was a UK lady also intressed! So that was you

Thats the charge curve you also talk about!

but still stated that this charger is not made for NIMH but for lead acid and that the charger got internal options like temp controlled voltage adjustents that will not work with Nimh but only for lead because thats where its build for.
and also told me to monitor or use a external temp sensor to simple shutoff the charger and no voltage adjustments.

You will go with a low current and not to high charge voltage to be on the save side!
But when you start charging the pack when its nog fully down to 20% the NG3 charger wil still keep charging for 10h. only stopping it because the prius pack gets to hot when you have a external temp sensor shutoff..
if not the pack wil become hot....and it wil not shuttoff and not adjust current or voltage because that option is only for lead acid!

so be carfull.

[aminorjourney]

This is really strange now because I've been told there can be a voltage cutoff at 238V - When my pack gets to that voltage then everything shuts off... :/

Anyway - If not I will of course use a voltage cutoff - 238V then Click!

[dmckinstry]

Originally Posted by aminorjourney

This is really strange now because I've been told there can be a voltage cutoff at 238V - When my pack gets to that voltage then everything shuts off... :/

Anyway - If not I will of course use a voltage cutoff - 238V then Click!

Norm (CAN-View) told me that you can set the Zivan NG3 at 238 V. I've been trying to get a Zivan charger, but they don't seem to know the charging curve at Electric Conversions (zivanusa). I have everything in my conversion set up, but no charger. Norm said at first to use a C7 curve. They didn't seem to have that. Norm gave me a TIF file with the SX curve, which he thought might be better than the C7 and I sent a copy of that to them, but there still seems to be confusion.

Anyone here using an NG3 with NiMH? Do you know what the best charging curve is? I want to set it up with a cutoff of 238 V with charging current of 4 A. I have two added traction batteries in parallel with it and am hooked up to Norm's BMS+. I've driven about 1000 miles, but the only charging I've done is by coming down a 17 mile long mountain pass.

Any knowledge would be appreciated.

Dave M.

[aminorjourney]

Hi Dave,

The UK Zivan agent does know about the SX curve. IT's something that the head office in Italy are developing for use with NiMH batteries. It may be worth contacting the UK distributor, Zapi UK, or perhaps the head office in Italy.

I've just officially placed my order, so I'll let you know how I get on!

Regards,

Nikki.

P.S. There's also someone who can modify a Zivan in the US to produce the correct curve - I'll see if I can dig out some more info...

[dmckinstry]

Originally Posted by aminorjourney

Hi Dave,

The UK Zivan agent does know about the SX curve. IT's something that the head office in Italy are developing for use with NiMH batteries. It may be worth contacting the UK distributor, Zapi UK, or perhaps the head office in Italy.

I've just officially placed my order, so I'll let you know how I get on!

Regards,

Nikki.

P.S. There's also someone who can modify a Zivan in the US to produce the correct curve - I'll see if I can dig out some more info...

Although there was some confusion at Electric Conversions, I think it was misconmunications, as I was asking them two questions at the same time, and they were probably replying to the second question. They do have the SX curve, and it's a curve with only a slight increase in slope on the voltage up to the target voltage, maintained at constant voltage with linear decrease in current to a target current (I guess I'm interpretting it correctly) and then a sudden drop in current to zero. The person I talked to on the phone did say it would turn off suddenly.

I'm going to call them again on Monday morning and see if I can get the charger that day.

If I do, I'll report after I've charged a few times.

Thanks for getting back to me. I'm assuming you are saying that the SX curve is correct (or at least ok) for the Prius prismatic cells.

Dave M.

[aminorjourney]

Originally Posted by dmckinstry

Although there was some confusion at Electric Conversions, I think it was misconmunications, as I was asking them two questions at the same time, and they were probably replying to the second question. They do have the SX curve, and it's a curve with only a slight increase in slope on the voltage up to the target voltage, maintained at constant voltage with linear decrease in current to a target current (I guess I'm interpretting it correctly) and then a sudden drop in current to zero. The person I talked to on the phone did say it would turn off suddenly.

I'm going to call them again on Monday morning and see if I can get the charger that day.

If I do, I'll report after I've charged a few times.

Thanks for getting back to me. I'm assuming you are saying that the SX curve is correct (or at least ok) for the Prius prismatic cells.

Dave M.

Hi Dave,

I am of course not an electrical engineer, nor am I an EV tech but according to what I've been told combined with what I've learnt about charging the SX curve seems to be the best. However, you'll need a way to turn off the charger immediately once 238V is reached and you'll need to build some circuit to make sure the batteries stay cool. Probably best there to talk to Norm about the charge safe device.

I'll be impressed if you can get a charger that fast. I've been quoted 6 weeks!

Nikki.

[Flying White Dutchman]

but ami
your getting the C7 curve or the SX?

[dmckinstry]

Originally Posted by aminorjourney

Hi Dave,

I am of course not an electrical engineer, nor am I an EV tech but according to what I've been told combined with what I've learnt about charging the SX curve seems to be the best. However, you'll need a way to turn off the charger immediately once 238V is reached and you'll need to build some circuit to make sure the batteries stay cool. Probably best there to talk to Norm about the charge safe device.

I'll be impressed if you can get a charger that fast. I've been quoted 6 weeks!

Nikki.

They already had it in stock. Greg (of ElCon) just had to tweak the current and voltage. I haven't had a chance to try it yet. I had to hook up a plug (AC 115) and wire up a connect. I didn't realize until I saw the unit that it came with an Anderson SB50 on it already. I just got the other SB50 (grey) from them.
It got dark before I could connect to the batteries in car. I'm away from home, so I'm going to have to go get a trouble light or good high power flashlight.

Oh. I almost forgot to mention, I'm using the C7 curve. The curve was for lead acid, but Greg set it up for 4 A, 238 V.

Dave M.

[ken1784]

I believe an absolute voltage (238V) on the NiMH batteries does mean nothing.
The voltage varies on many conditions, such as temperature, current, internal resistance and so on.

Also, please remember that Toyota limits the upper SOC to 80% to extend the cycle life.
We saw up to 84% SOC, and it'll be acceptable to charge it up to 90% SOC, maybe.
Anyway, we have to monitor/calc/control the SOC to see the reasonable cycle life.

Ken@Japan

[Flying White Dutchman]

Originally Posted by ken1784

I believe an absolute voltage (238V) on the NiMH batteries does mean nothing.
The voltage varies on many conditions, such as temperature, current, internal resistance and so on.

Also, please remember that Toyota limits the upper SOC to 80% to extend the cycle life.
We saw up to 84% SOC, and it'll be acceptable to charge it up to 90% SOC, maybe.
Anyway, we have to monitor/calc/control the SOC to see the reasonable cycle life.

Ken@Japan

so bottomline to your "238b means nothing" if you set the charger to 238volt max is not that simple?