I Zip Skyline problem

[hobgoblin59]

Hi everyone, I just found this forum and hope you can help.

I have a Currie Izip Skyline which is about three years old and has never had any problems until now.
This morning I went out on it, battery fully charged, and found that every time the motor kicks in the bike switches itself off. It won't switch back on with the switch on the handlebar panel, I have to switch the battery key off and back on again, then as soon as I put any load on the motor the same thing happens. I have checked the battery terminals and every connection and fuse I can find.

Any ideas what the problem might be?

Thanks in advance for any help.

 

[flecc]

It's most likely to be the battery at fault, since two to three years is a common life for lithium batteries in this sort of price bracket. The failure is usually like this, the voltage collapsing as soon as a load is applied.

It looks like a fairly standard 24 volt lithium battery but it may only be obtainable from China. If d8veh sees this he may be able to advise the best source.

 

[Deleted member 4366]

Yes, it looks luke a standard battery. Something like £150 to £200 from China.

Can you measure it and post the dimensions?

If you want to find out what's wrong with it, you have to open it up, peel of some of the heat-shrink and measure the cell voltages at the BMS. Sometimes you can get a bit more life out of it by rebalancing the cells.

 

[hobgoblin59]

Hi d8veh

Battery is 380mm long excluding handle, and 85mm square. It has the numberZL07010-F on it if that helps. Can you point me to somewhere I can order one from?
Many thanks.

 

[Deleted member 4366]

You have to do a search for "silver fish battery" on Aliexpress.com. be careful though, they don't always show the correct picture. Read the description and then confirm the size with the seller.

What's the voltage written on the charger? It could be LiFePO4.

 

[Deleted member 4366]

There's a LiFePO4 one on Ebay. Search for 24v/36v LiFePO4.

 

[hobgoblin59]

Thanks for that, I'll have a look.

 

[hobgoblin59]

OK, before I order a new one I would like to open the old one up and check it. What voltage am I looking for across each cell? Is it 24v divided by the number of cells, and if any of them are less than that then the battery is no good?

 

[Deleted member 4366]

When you get to the BMS under the heat-shrink, it has a multipin connector. Put your black probe on the thick black wire that comes from the cell-pack, en probe each pin on that connector, and finally check the thick red one. That makes one reading for each pin plus one.

The difference between them is the cell voltages. The seven cells should be between 4.15 and 4.2 fully charged.

You should do the test again when 5he battery has cut out to see which cells are low.

If when you peel back the heat-shrink, you find swollen cells, that's your problem.

You didn't give us the voltage off the charger!

 

[hobgoblin59]

Sorry i cant give you the voltage off the charger because I am not at home now, I will be back on Monday so I'll have a look then. Thanks very much for the info, much appreciated.

 

[hobgoblin59]

Hi again, the charger says output 29.4v.

 

[Deleted member 4366]

That means that it's a seven cell Li-ion one (I.e. not LiFePO4). You can replace it with a LiFePO4 one if you want, which is better, but a bit heavier and probably more expensive.

I looked at that Ebay advert again and found that it's a bit misleading. It would be best to Email him with your requirement to see if he can help. Any 24v battery of the correct size should fit, although you might have to do a bit of jiggery pokery with the connector at the bottom.

 

[hobgoblin59]

Just tested the old one as you suggested, one cell is only reading 1.8v, so I think it's new battery time.
Thanks very much for all your help.

 

[Deleted member 4366]

If you left it a long time (months) without charging, it might be recoverable by charging the low cell on its own. It's worth a try anyway. You need any 4.2v or 5v charger. An old phone charger, vape stick charger or USB charger should do it. It'll probably take a long time. Keep checking if you use a 5v one because you mustn't charge it past 4.2v. You have to stop it at the right time.