[Noob] Bought an old Guewer ebike, having some trouble

[torco]

Hey. I'm sorry if this is an obnoxious noob question -everyone's pretty knowledgeable here - I mean I've done some reading but I haven't got much hands-on experience with Ebikes: they just sounded like a great idea in theory so I took the risk; we shall see if I'll regret it, but i certainly hope not!

Anyway, thing is I recently got a Guewer ZW-TDF-105Z (link) that was recently upgraded to a 500w DD motor. Yeah, I know, the frame's pretty low but its light, its got disc brakes and in general the bike is decent quality for the price I got it at [about four hundred bucks]; hell, even without the battery I got the original geared 250w engine, the 500w brushed engine plus a decent frame, the controller and all that, so I didn't get *that* shafted: From what I gather 800 bucks is a normal price to pay for a decent ebike, right? plus I get the geared engine if I ever want to fiddle with it.

Its a decent machine and it runs fine <even if the brushed engine does offer some resistance when trying to pedal without power>. I mean, its pretty fun! Thing is the battery is quite spent, like I can only get some four and a half kilometers on the motor alone out of it before the battery dies* and you're left to pedal against the brushed engine, which is not very fun at all. So I'm thinking I'm gonna have to buy a new battery pack.

And here is where I'm kind of lost. The original battery pack <which fits into a rack equipped with some sort of plastic box that has five male pins in a line, while the battery has five female pins in a line and snugly fits inside the rack> is a Phylion XH370-10J(10IMP18/66/133(10)-004) "high energy battery" <for all that's worth> 36v pack. So the thing is that Phylion's page states that the pack is good for 500 cycles [500times(cycle@RT,1C rate,100%DOD), whatever the rest of it means]. That specific part can be found on eBay for something like 400 bucks [picture]... whereas a local supplier in my country** sells batteries for the same price except they claim these are good for 700 to 1000 charge cycles. [this is the pic, for what its worth].

Now, I rather prefer to buy from a local guy and not have to worry about shipping and import taxes and dealing with DHL or some other shipping company. But the thing is, I would have no idea how to make a new battery fit into the bike: ¿would I have to get a controller? the five-pin head looks like it can be screwed off the battery itself; ¿maybe it can be wired into the new battery and have the whole thing work fine?

*note: I assume the matter is that the battery is spent, I mean, I'm riding and the bike suddenly turns off, so I flick the switch off and on again and the lights come alive again only for me to twist the throttle, get half a second's worth of power and have the motor and the lights die again. Which is funny, since the battery meter reads full on the screen, but since it resumes normal operating capacity after plugging in the charger for a few hours I assume what's happening is that the battery is old and spent and can only hold so much power inside it. My conclusion is that the battery has reached its life's end, or very nearly <so the guy sold me the bike with a near-death battery... which, hey, explains why he sold it so cheap so I guess you get what you pay for>.
** oh, yeah, I'm chilean by the way... which somewhat limits my access to spare parts, but these days with international shipping things are good.

Anyway, sorry for the long post but you never know what information could become useful. And thanks in advance for taking the time to read this.

 

[amberwolf]

Sometimes a battery is simply unbalanced, not all cells fully charged, so you might just leave it on the charger for several days, maybe a couple of weeks, and then see if it works any better. If it's really badly out of balance, some BMSs rebalance so slowly that it could tkae weeks to rebalance it that way.

You can look up threads about battery balance and troubleshooting and single cell charging to find out how to check and manually recharge the cells if that's what's wrong.

 

[torco]

I suppose there's really nothing to lose by messing with the battery.
But many thanks, man, I'll try leaving the charger on for as long as I can and check out that battery unbalance thing.
Here's hoping!

EDIT: is it safe to leave a battery charging for an extended period of time? won't it explode or something? 0_o

 

[dogman dan]

It shouldn't be a problem with that kind of cell. The volatile type are the cheap RC toy cells.

The bms requires a lot of time on the charger to do its job, so leaving a battery on the charger overnight at least once in a while is needed. But that doesn't mean do it on a pile of newspaper by the curtains in the babies room.

Replacing your old battery with one that is pretty different is possible. Find one of similar voltage, but you may need a new charger to go with it. The hard part will be finding somebody who knows the wiring of your bike. If you can get a diagram from some website, that would be great.

You will have to take things apart enough to know what prong does what on your plug, or replace the plug entirely with new plugs. Each production bike does things slightly different, often depending on accessories that are not on kit build homemade ebikes. But tracing the wiring harness of your bike and taking good pictures of it may allow one of us to decipher things.

 

[dnmun]

I suppose there's really nothing to lose by messing with the battery.
But many thanks, man, I'll try leaving the charger on for as long as I can and check out that battery unbalance thing.
Here's hoping!

EDIT: is it safe to leave a battery charging for an extended period of time? won't it explode or something? 0_o

you should post up a picture of your battery and the BMS so we can show you where to measure the individual cell voltages in order to examine it.

 

[torco]

Well, I left the charger to charge it up overnight and... the charger died. which is probably the charger's fault, the bike is pretty old.

At any rate, thanks a lot, guys. I'm gonna post pictures as soon as I get home... in the meantime, the bike has a black thing in the rack out of where many cables come out of, including the one that feeds the tail-light, screen, and throttle. Does that mean that the controller is inside the rack?

[what I would imagine is that the battery provides a simple power outlet and from there the controller takes care of coordinating all the other parts].

 

[dogman dan]

Step one, start a new thread in ebike general discussion. Ask if anybody is experienced with the brand of bike you have. Include links to any websites for it you can find.

Buried here in the battery section, only a few of us will read it. You need a person who has had one of these bikes, and taken it apart.

Here in this thread, we might still be able to help you fix your battery. But it's pretty likely it's damaged and unfixable. That does not mean learning about how it's put together is a waste of time though. You need to learn about batteries to get into this kind of vehicle, or you need dad's charge card.

 

[amberwolf]

Rather than starting a new thread, I'll just move this one over there, so all the existing info is in place for reference.

If you like I can change the title of the thread to something like "troubleshooting a Guewer ZW-TDF-105Z ebike".



regarding the charger dying: My guess is that it's fixable if you want to try, but that it could actually be the cause of the battery not having hte range you expect of it: if it never fully charged the batteyr because it was not working right even before dying, the batteyr wouldn't last as long as it should.

Alternately, something wrong with the battery could've killed the charger but that's much less likely.

I would guess that the charger has blown or swollen/leaky capacitors inside, if you open it up. If it has a fan and the fan stopped or didn't move enough air, it would cause it to overheat. But this is all speculation.

 

[torco]

Rather than starting a new thread, I'll just move this one over there, so all the existing info is in place for reference.

If you like I can change the title of the thread to something like "troubleshooting a Guewer ZW-TDF-105Z ebike".



regarding the charger dying: My guess is that it's fixable if you want to try, but that it could actually be the cause of the battery not having hte range you expect of it: if it never fully charged the batteyr because it was not working right even before dying, the batteyr wouldn't last as long as it should.

Alternately, something wrong with the battery could've killed the charger but that's much less likely.

I would guess that the charger has blown or swollen/leaky capacitors inside, if you open it up. If it has a fan and the fan stopped or didn't move enough air, it would cause it to overheat. But this is all speculation.

that's a much better idea, thanks. the charger hasn't got any fans or anything... its actually much lighter than my laptop charger, which strikes me as odd... I'll see if I can't open it up. Come to think of it, the seal is broken so it *has* been opened before. If I do manage to open it I shall post pics too.

 

[d8veh]

All the Phylion batteries that I've had for repair, were totally worn out with very little capacity left in the cells. I could get them nicely balanced at charged, but after 1aH, cells were already reaching LVC. I've never had that with other cell types. Also. they don't seem to last a long when you give them a hard time, so I think that the 500w motor might have expedited their demise. By all means, check yours out, but I think you'll be looking for a new one capable of 500w. Your battery has 5 pins. Normally the outer two are the power lines and two of the middle ones are for a switch that can switch off the BMS. If there's no switch, they might be left disconnected. You need to open te box on the controller side to see what's connected and where the wires go because there's other possibilities.

You can still get any battery regardless of connectors. You only have to run the wires to the controller, and you need to determine if the controller needs an ignition wire via a switch. Post some pictures of the controller's connectors, and we should be able to help with that. Ideally, you need a battery of at least 15aH to get the required current unless you get a high-discharge rate one. You should pull out rhe controller to see how many amps it's rated at. It should be written on it.

 

[torco]

Haven't been able to take the pics cause I decided to leave it to the repairguy so he can check whether its unbalanced or what.
I wouldn't mind getting a new controller, they're not so very expensive after all... but are 36 volts enough for a 500w engine that's pulling a 100 kilo man ? or do I need to get up to a 48v one ?

 

[dnmun]

most repair people have no idea how batteries work. but at least you will get a new battery out of it. just an expensive lesson to learn. depending on others in this hobby can be very expensive.