ZX40S Batteries popping like popcorn!

[rmay635703]

Originally Posted by stou0220

I checked the charging side of the charger and it is pushing about 80-81 volts. I also checked each battery, and they vary from 12.3-13.3 after 2 hours of charging. The exception is one of the temp batteries I put in, a deep cycle from Wal-Mart that is at 15.5 volts. Should I be worried about this battery? BTW the bad batteries that I pulled out are also showing a 12.5 or so volt reading. I will forward this info to the deal to see what he says.

It is best to avoid charging a battery for extended periods above 15 volts except maybe during an equalize charge.

Try to run a load test on one of the bad batteries and you will see it can't put out but maybe a volt under any load. those batteries have blown interconnects or plate material blew, which on an AGM is fatal to the battery.

It is possible they were overcharged after sitting which can dry the plate then you get tons of heat and break connections or it is also possible they are just plain junk from the factory, extreme jarring can do that as well.

Good Luck

[stou0220]

I found a number imprinted into the top of the batteries that includes the date. The three batteries that blew all were manufactured on 10/03/2006, so they were all 3 years old! The others were 2 years old. The ZX40S manual itself says the batteries should be replaced if older than 24 months. I was told they were putting new batteries in the car when I bought them, so clearly somebody didn't do what they were supposed to.

Anyway I escalated the issue to upper management, and they responded that they are going to send me new batteries, so hopefully this is resolved. These batteries were simply very old, and should have been replaced in processing. Thanks for all the info and I will keep you informed of my progress!

[MetroMPG]

Sounds to me like a classic "unbalanced pack" problem.

The old batteries had a much lower capacity than the others, so they were depleting faster than the newer ones. When they "blew", I suspect that was the result of a cell reversal - the voltage in an individual weak cell was drawn down to zero, at which point it reversed and started being charged by the neighbouring cells. ... At 100+ amps, or whatever the current was while you were driving!! That much current will generate a lot of heat and gas, and a BANG! isn't out of the question.

I'm a firm believer that all EV's need pack monitors: either passive (by computer, with appropriate warning methods) or active (some kind of array of gauges the driver can keep tabs on).

The battery pack is usually the most expensive component in the car, so it just makes sense to monitor it in a more sophisticated way than a single "state of charge" voltage gauge.

EG see: http://ecomodder.com/forum/showthrea...raph-8216.html

You can also get commercial versions of that: Pak-trakr is one.

[rmay635703]

Sounds like your dealer didn't do its job.

If you would have known there were old batteries you could have followed Miles battery restoration procedure and likely all of them would come back, sadly I found out after it was too late for one of my batteries, but I saved 2 and one is workable but not as good.

If for some reason you get a full pack and can keep some of the batteries I would be willing to throw in a few bucks to get a few of your used ones that are in better shape.

Those batteries are a REAL pain when they sit unused you have to baby them and cycle a bunch charging each battery individually until they come back which can take a dozen cycles or more.

Cheers
Ryan

[stou0220]

Well, after much letter writing to everyone at Miles, I was able to get 6 new batteries and a new charger. I guess making the CEO of the company aware of how his company is mistreating a customer pays off . Anyway, I will be recycling the 3 batteries that blew, but the other 3 appear to be OK, but maybe could be desulfated. All three that blew had a 10/2006 date, while the others are in the middle of 2007 range. I thought about sticking these on eBay but if you are interested in some of them let me know!

BTW, the car runs much better now than it did before I had the battery issue. With field reduction it goes 35-40, and the range is more than enough, as the most I will drive is 8-12 miles round trip. Now if I can just get it to go 45-50 I can would be happy.....

[MetroMPG]

Just out of curiousity, did you consider an EV conversion before getting the Miles?

You likely could have achieved your range & speed goals for the same or less cost.

PS - glad to hear you got the battery situation resolved.

[stou0220]

Hi MetroMPG,

I actually am in the early stages of building an EV with a close friend. It is on pause atm as we decide what kind of vehicle to use. Originally we were going to use a Kia Sportage, but the one we were going to use has a salvage title, and now we are considering something with a clear title. Once we get going on that project I am sure I will be soaking up the knowledge on this board! Anyway, our goal is to have a 4-seater that has ~30 mile range.

I agree the costs of this car rival building an EV that goes faster. However since this is a new (never sold before) ZX40S, the substantial tax credit I should receive next year makes this car a pretty good deal....especially now that it has new batteries and a new charger!

[Christopher Jordan]

Fascinating thread! My batteries do not "pop" or warp or overheat; but I have had similar charging problems over a year (overcharging, reverse cell, many of the same voltage numbers). But I have computer stuff that does not belong in the charging circuit- 4 computer power supplies (3 even charge- sometimes) and 1 start and rapid floor charger. But with dumb luck I got lots of miles. Just not worth repairing- the batteries were new in 2007 so when they go they GO!

[rmay635703]

Originally Posted by stou0220

Well, after much letter writing to everyone at Miles, I was able to get 6 new batteries and a new charger. I guess making the CEO of the company aware of how his company is mistreating a customer pays off . Anyway, I will be recycling the 3 batteries that blew, but the other 3 appear to be OK, but maybe could be desulfated. All three that blew had a 10/2006 date, while the others are in the middle of 2007 range. I thought about sticking these on eBay but if you are interested in some of them let me know!

BTW, the car runs much better now than it did before I had the battery issue. With field reduction it goes 35-40, and the range is more than enough, as the most I will drive is 8-12 miles round trip. Now if I can just get it to go 45-50 I can would be happy.....

You would need to contact a dealer in Ohio if you want to go faster he has transmission parts that are needed to do that.

It is good that you got a full set from miles, make sure you take good care of them. Those batteries like an occasional Deep discharge down to about 11.5 volts followed by a full recharge but no further (that how they are revived after sitting) And NO you can't desulphate those batteries, I have tried and it does not work, makes them worse. You can only cycle them back and forth from approx 11.x volts back to full charge repeatedly at a high charge rate to bring them back.

In any event I am interested in your 3 batteries, that would work perfectly for me but sadly I live in Oshkosh, WI, my folks in Wausau Wisconsin. The shipping to get the batteries here likely would be too much.

The trouble with those batteries is if they are abused even once they go downhill and crash and burn as you observed, they are large and proprietary, shipping could easily be $100 each depending on how they get sent. Two of my original 4 that got abused slightly eventually crashed and burned all shorted out.

If we can figure a way of getting them from you to me using FOF's or folks on the board I would be willing to buy them at the current scrap value.

Not sure how we could ever work that out though. You might have to PM with a phone and see if anyone would be interested in slowly migrating your batteries up to me.

Cheers
Ryan

[stou0220]

Well maybe we can figure out a way to get them up north. These are supposed to be unused batteries, but I am certain this is inaccurate. So much for getting what you were sold these days.

So there is a dealer in Ohio that sells the transmission parts for this car? I heard the 2005-2006 models have the gearing in them while the 2007 and later had them stripped out except the one gear. If this option would provide better hill climbing with costing a fortune then I am definitely interested.

Maybe this is the start of another thread, but the thought had crossed my mind to just replace the motor and controller with something more powerful, something like the D&D ES-31B. Have any ZX40 owners done this that you all have heard of?