ZX40S Batteries popping like popcorn!
 

Hello All,

I recently got my 'new' 2007 Miles ZX40S, and after driving it 3 miles a battery blew. I stuck Walmart's finest battery in as a replacement (to get the car home), and after driving it about 4 more miles two more batteries blew. These are the huge Chinese batteries that come with the car. I don't know if the batteries are bad or something is causing them to blow. I am working with Miles, who said before they shipped the car that the batteries put in were new, but it is very painful to get them to do anything. Anyone have any suggestions on what to troubleshoot?

Thanks!

Are the cases warped?

Are the terminals good?

Did you drive the car before charging?

That is indeed a very strange occurance, however if those glass mats were dried I do know that they fail by having cells blow apart.

Good Luck

The cases were not warped, nor do the terminals appear to be bad. When I got the car I did drive it about 1/2 mile before charging, and everything seemed fine. I charged it for 6 hours or so, and drove it 2 more times (1-2 miles each), when the first battery blew. I think it 'gassed' (not sure), as each time the the pack voltage dropped by 12-13 volts and the battery whistled like a tea pot. I could smell the vapor in the air.

The dealer said it could be a bad charger, but I don't have enough experience with this to understand how. I don't know if I just had 3 bad batteries or something systemically wrong. Any other suggestions?

Those batteries are normally not very picky about charging, but I do know you need to avoid overcharging, especially if the batteries sit a long period.

When those batteries sit you need to draw them down to roughly 10.5 volts before you charge them then continue to do so and the capacity increases (at least thats how it worked with mine)

If the batteries gas while charging it can be problematic since they are sealed AGMs.

I would definately use the warranty but if your stuck you should check to see what the batteries did.

Good Luck

It probably shorted out, it is possible that you had a bad charger, many times Miles used cheap chinese chargers which are only semi automatic.

Is the charger in this car a 'smart charger'? I don't think I overcharged, nor did I know it was possible with the the charger it comes with! I thought this came with a 2 or 3 phase charger that wouldn't overcharge. I read the manual that came with the car, and I don't remember any over charge warnings, not that it isn't a risk. Anyway, I am trying to get Miles to replace the batteries, as they prepped the car and certified it road ready. However, they don't seem as eager to send me the batteries as they were to take my money when I bought the car. I hope I can get this resolve quickly, but I am not optimistic at this point.

If I can't get Miles to replace these, I thought about replacing all of the batteries with 9 8-volt, 165 AH golf cart batteries. These are wet batteries, not AGM or gel. I don't need much range, 20 miles or so, but I don't know how these batteries would affect performance, which I am concerned about. Do you have any experience with batteries that aren't $350 each? I am sick of spending money on a car I haven't been able to drive yet!

In my car it isn't very smart, although it will shut off after running a specific period on float. The miles chinese chargers are prone to failure so make sure they test the thing.

Also the batteries listed in my manual are $250 each but that shouldn't matter they should be under warranty, let them look it over, let em baulk but if they died in short order there was something wrong out the door.

If you get different batteries the miles charger brings them up to about 15v (on a 12v battery) Which some batteries don't like.

Also those big 150ahr batteries have a LOT of capacity, smaller 8v batteries will likely provide less range than properly working Miles AGM "150ahr" batteries, reason is 150ahr seems to be under load and not a 20hr rate.

Good Luck

Unfortunately I live in South Carolina, about as far away from Miles as I could be in the Continental US! Even the closest service center is ~700 miles away according to their dealer map. So Miles can't troubleshoot this themselves. The dealer I bought it from is trying to help, and suggested I check the charging side of the charger to make sure it isn't pushing more then 72 volts and frying the batteries. I will do that today. Thanks again for the replies, I will update the thread as I get more information.

You are about as far away as I am, in any event you need workable batteries of some sort in the car to test the charger, the charger (if your car is a 72v car) should charge the batteries up to between 84-90 volts NOT 72 volts which is your nominal, Those miles batteries when new sit around 13.3 volts without the charger running when fully charged. Anyway the charge should climb up to 84-90v depending on the temperature then sit there a long time then drop down to the float mode then the charger shuts off, Miles has used different types of chargers so it may vary a bit but not by much

Something else you should check is ARE all the batteries at the same voltage before you charge?

If one is way low and the others are way high you can blow out batteries since the charger will drive them up over 18 volts ea if you have one that isn't coming up correct, so take care.

Good Luck
Ryan

Thanks for all the info, Ryan. I do have a question. If the charger was causing the battery problems, wouldn't they blow on a charge? So far all 3 have blown when driving the car. Once they get hot and blow, the vehicle doesn't run (well maybe 4-5 MPH top speed). I would think I wouldn't get it out of the driveway if the charge was blowing them, unless they cool down and don't have problems until they heat up again.

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

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!

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.

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

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 :D. 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.....

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.

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!

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! :D

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

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?

Actually I would be more hopefull if they were used, these batteries do not SIT well, under use they seem to live long lives so long as they aren't overdischarged or underdischarged and overcharged. After they sit you have to discharge them under a watchfull eye to a specific voltage and then recharged dozens of cycles to possibly bring them back.

He has been selling junk transmissions from the offroad cousing Miles OR70 to get better gearing. Sadly I think he has run out which will mean mega price jump to order from china new. The trouble is only older OR70's had all the gears (but still no linkages), many still only have 2 of the gears which is still better than one gear like the zx40. And if you think you can find an older zx40 that has multiple gears forget about it, only maybe 5 including prototypes had 2 gears instead of one, likely the folks that have them won't give em up easily and I would estimate a few are sitting at Miles Corporate more or less permanently.

There is a motor D&D custom made to fit certain miles vehicles (aka has the really really strange shaft), I am uncertain if it is much better or not.

One issue is that there are 4 motors, the small 48v motor found on old ZX40's like my 05, the small 48v/72v motor found in some "Transitional" zx40s, the big 48v/72v motor found in the newer ZX40's and the older OR70 and the AC drive motor.

Being you have an 07 you probably already have the big motor anyway. Give me the serial and tag model info on your motor to humor me, I will see if its the same or different than my antique.

I somehow believe that my tinker toy 5hp motor is likely not easily upgradable and likely folks with the bigger motor already have one that is as big as will fit making the D&D moderately moot.

Only way to know would be to contact D&D and see what they think.

I am not sure where to find the motor serial and tag, I don't see it on the motor. I wasn't aware that the shaft was so strange, although I am not surprised. Some custom lathe work should be able to solve that hurdle if necessary, although it is costly.

I am still learning with this project, but how wouldn't a bigger motor yield greater performance? For example, the D&D ES-31B is a 72-120 volt motor that is rated at 25 HP continuous, 40 HP Peak. I know range is sacrificed, but wouldn't this motor provide greater speed? Or are my gear ratios restricting too much to make a difference?

Regarding the batteries, I can't tell you what happened to them before I got them, but those 3 appear to still work. I may end up in the midwest sometime in the next 3-6 months, but if we can work out a way to migrate them to you before then I say let us do that!

The shaft and the mount, the motor sits in between sort of a cradle that limits what you can do.

Yes a bigger motor has more power but only if it fits in there, which is questionable.

If your car is like mine, You will be turning around 6300rpm's give or take at 45-50mph. Changing your tire size helps a little but getting out of 2nd into 3rd gear is what makes a hi-speed miles feasable.

Regardless of their condition I am willing to "try" messing with them the way I did on the 05's that came with this car, likely some will come back fully and some will probably die in a few months.

I came across a gentleman who said he replaced the tranny on his ZX40 with a 2001-2005 Perodua Kenari transmission. Here is what he emailed me:

The tranny came from GB. It is Perodua Kenari 2000 to 2005 model. This is
basically the same car like Daihatsu Move, but cheaper and popular in GB.
I bought it just by picture - it fit in the space and the mounts. I needed
to drill 3 additional holes in the adaptor plate and grinded the CV joints
(developed slow transmit ion leak).
The gear stick came from WV Passat - it is with rods (not with cables).

I am going to contact him to try and get pictures. I thought you may be interested in a different potential solution to our speed limitations!

I am MOST CERTAINLY interested, however where is GB, around here that means Green Bay but I doubt that forgetting my foreign abbrev.

Anyway I knew Perodua made clones of Daihatsu vehicles, sadly I knew of no inexpensive way of getting Perodua parts much the same as Getting the transmission from Japan. The shipping is probably more than the transmission.

Anyway if you can find out how much this costs and how to get one, I'm in, especially if that guy does the necessary machining on the flex plate :)

And what in the heck is a Slow Ion leak and how is that fixed by machining?

Cheers
Ryan

Lol, GB is Great Britain I am afraid. And you are right, shipping for him was more than the part. Here is what he sent me last night:

I bought the tranny from Ebay - Perodua Kenari 2000 - 2005. 130 GBP and 200 GBP shipping. It took some additional holes to be drilled on the mounting
plate, but even it's a little bit bigger than the original - it fit. The
joints are slightly different, and I had to work them to fit (I have slow
leak from the tranny seals (where the u-joints go in it).
My setup is clutchless, and I am using mainly 4th and 5th gear. On 4th -
decent acceleration to about 32 mph, 5th - maintains 40 on flat, if you push
- goes 45mph. Max speed slight downhill - 52mph (so far). This is without
field weakening.

He also sent me some pics, if you want I can email them to you or post them somewhere.

You can post them here if you like, I am uncertain why you would want a 5sp transmission when the 4 speed is likely fine, also something important, what voltage was his car?

When I did the calculations for the stock differential and transmission for a daihatsu move (aka 4sp) with my stock 48v motor. I came up with a top theoretical speed of about 52mph in 4th - losses or about 45mph. Apparently a 5sp ends up at about the same final drive ratio as the 4sp. The odd part is his comment about 4th gear, folks with a 72v miles typically can get up to about 40-45mph in 3rd gear of the stock 4sp transmission from china.

I can only guess he has a 48v car and his final drive ratio is the same on the 5sp as on the 4sp apparently.

If you can PM or Email me some pics / info along with this gentlemans contact I would like to speak with him. Oh and make sure he knows,
High gearing + field weakening = disaster. Field weakening is good when you need to rev the motor up to a higher RPM under a moderately light load, under heavy loads its just a bad idea. He would definately need an accurate ammeter to see what is going on, likely 5th is overampping his motor a bit already.

Cheers
Ryan

Ryan,

I will PM the pics. I'm sure he won't mind, but let me ask him if it is OK to forward his information to you, just as a courtesy as he has been very generous in sharing his experience.

On a separate note, I tried a little experiment tonight with the car my friend has. We took my best spare battery, charged it up, and made his car 84-volt. I have heard of others doing this, but I don't know if anyone has done it with field weakening. The car gained 3-5 mph. The road we speed test on is a slight hill, about 3/4 mile long. We got the car about 46 MPH going down, and more impressively it accelerated to 37 MPH going up the hill. Previously it would only do ~33 MPH up that same hill. We don't if we will keep the car like this for a variety of reasons (motor health, charging, looks like hell), but it makes that car move!

Well I took the 7th battery out, at least for now. The charger is only pushing ~87 volts, and it thinks the pack is charged when the batteries aren't fully charged. Also, it just looks like crap. I will have to see how much I miss that extra oomph before I decide if it is worth pursuing long term.

My main concern is that the controller in there is only 72v, going past that usually causes the magic smoke, especially after a fresh charge, AKA bad idea batman.

Field weakening isn't a big deal, you just need to know what the motor is rated at and how much juice you are pressing through if you are running near the ragged edge and then do field weakening things break. Your motor is likely much larger than mine (erm 5hp tinker toy) so it likely will survive where mine won't

Thank You
Ryan

I appreciate the feedback, Ryan. I moved back down to 72-volts. I would rather not destroy the motor, so I can sell it once I finally rip it and the Curtis 1209B out and put a bigger one in its place. Driving this car is like going to a strip club: you buy the goods knowing how far you can get, but once you get there all you think about is getting a little more!

If you do ever get up near wisconsin-ish let me know. I'm not much of a networker so likely no one going between you and me.

Anyway I still wouldn't mind that guys email, I am curious about his specific configuration.

Ryan, here is a link to the photos. I will PM you his email address

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