Yamaha Easy battery charger wanted.
- Thread starter TS Hat
- Start date
This is probably the same battery as the Yamaha Super of the following two years, a 24 volt NiMh one. Almost no e-bikes use NiMh any more having switched to lithium batteries long ago, so in consequence suitable chargers are between scarce and not available in the UK.
One company in the USA stil supplies them though and I and others have bought them from there. These e-bike NiMh batteries have to have chargers that match the value of a thermistor in the battery and the US supplied charger does match a common generic value, but that's not a guarantee that it will match your battery's thermistor. If it doesn't, you can change the one in your battery if you're happy to open it and solder a diferent one in. We can give the details on how to do that if necessary. You may also have to change the connector on the supplied charger to match what your battery has.
You'll find the details on buying one of those US supplied chargers on my webpage for a similar e-bike that also uses these batteries, the same part number applies, link here.
But before going further you should also bear in mind that your NiMh battery may well be completely dud at that age, and they are also not available. You could fit a set of 20 new cells but there are few adequate ones available now and that could easily cost up to £200 or even more.
If the battery is dud as well, a better solution can be to buy a new lithium battery and charger direct from China. However it wouldn't fit directly into your bike and you'd have to arrange a different mounting such as on the carrier and arrange connection leads into the bike's battery platform connections.
.
One company in the USA stil supplies them though and I and others have bought them from there. These e-bike NiMh batteries have to have chargers that match the value of a thermistor in the battery and the US supplied charger does match a common generic value, but that's not a guarantee that it will match your battery's thermistor. If it doesn't, you can change the one in your battery if you're happy to open it and solder a diferent one in. We can give the details on how to do that if necessary. You may also have to change the connector on the supplied charger to match what your battery has.
You'll find the details on buying one of those US supplied chargers on my webpage for a similar e-bike that also uses these batteries, the same part number applies, link here.
But before going further you should also bear in mind that your NiMh battery may well be completely dud at that age, and they are also not available. You could fit a set of 20 new cells but there are few adequate ones available now and that could easily cost up to £200 or even more.
If the battery is dud as well, a better solution can be to buy a new lithium battery and charger direct from China. However it wouldn't fit directly into your bike and you'd have to arrange a different mounting such as on the carrier and arrange connection leads into the bike's battery platform connections.
.
Last edited:
Very grateful for the comprehensive advice - thanks, flecc. I'll wait a bit to see if anybody comes up with a second-hand charger; failing that I'll probably order the US one. I'd welcome your tips on how to open the battery casing and access the charging connector in order to replace it, though.
Best regards, TS Hat
Best regards, TS Hat
You won't have to open the battery to change the connector though, if the connection needs changing it will be the one on the charger lead that's changed. We won't know that until you have the charger of course.
I don't know what charging connector your battery has, but if it doesn't match the charger one a photo of your battery connection should enable us to recognise it and advise the right one for the charger lead. It will also be necessary to check the polarity of the connection is right. Hopefully there's a shred of charge left in the battery to enable the polarity to be recognised by a multimeter, if not some lead checking will be necessary which might entail opening the battery case. (Bear in mind that if there is absolutely no charge in the battery to operate the meter reading, it's more likely that the battery will be useless, which could make it worth considering whether to risk buying an NiMh charger.)
Otherwise the battery case will only have to be opened to change the thermistor if the charger doesn't operate properly with your battery. Most use a generic value NTC thermistor so the odds are on your side that it will be ok, but if not we'll cross that bridge when we come to it.
.
I don't know what charging connector your battery has, but if it doesn't match the charger one a photo of your battery connection should enable us to recognise it and advise the right one for the charger lead. It will also be necessary to check the polarity of the connection is right. Hopefully there's a shred of charge left in the battery to enable the polarity to be recognised by a multimeter, if not some lead checking will be necessary which might entail opening the battery case. (Bear in mind that if there is absolutely no charge in the battery to operate the meter reading, it's more likely that the battery will be useless, which could make it worth considering whether to risk buying an NiMh charger.)
Otherwise the battery case will only have to be opened to change the thermistor if the charger doesn't operate properly with your battery. Most use a generic value NTC thermistor so the odds are on your side that it will be ok, but if not we'll cross that bridge when we come to it.
.
Last edited:
Thanks again, flecc. Battery gives about 17V on my multimeter, from both input and output connectors - see photos. I'd be glad to know if there's an appropriate input connector available.
The left hand terminal in both connectors appears to be +ve.No luck on a used charger - looks like I may be contacting the USA!
Attachments
Unfortunately that four blade connector doesn't look like anything standard, a problem we've had with Japanese e-bikes from time to time, so I have no plug on solution for that. You could either rig individual plug-on connectors or more easily arrange a jumper lead to a form of standard connector. Usually only three connectors are necessary.
If you check the battery output terminals from the neutral (thermistor ground) to the other connectors with your meter on a resistance range, you will find another one recording about 10k or more resistance. That will be the other thermistor connector. The charger's thermistor circuit is across it's neutral and third lead, the remaining one positive charge of course.
On the US charger the centre pin of the supplied connector is the thermistor positive. If you do order the US charger, specify an XML connector since it's easy to buy a matching one here for your jump lead into the battery. The standard female connector they fit is a type not used here so matching plugs are difficult to source.
.
If you check the battery output terminals from the neutral (thermistor ground) to the other connectors with your meter on a resistance range, you will find another one recording about 10k or more resistance. That will be the other thermistor connector. The charger's thermistor circuit is across it's neutral and third lead, the remaining one positive charge of course.
On the US charger the centre pin of the supplied connector is the thermistor positive. If you do order the US charger, specify an XML connector since it's easy to buy a matching one here for your jump lead into the battery. The standard female connector they fit is a type not used here so matching plugs are difficult to source.
.
I've been in a similar position: bought a Yamaha Easy on eBay a year ago. It came without a charger. I bought a generic Nimh charger which didn't work so I assumed the battery was dead. But I recently tried charging it with my Imax B8 charger, and it worked! I didn't use any temperature sensing, just charged the battery up to 29.25 volts. I need to do a bit more research into how not to overcharge the battery. I haven't found a solution to the connectors; at the moment I have just used the crocodile clips that came with the charger.
There is a similar, cheaper charger, the Imax B6 which might also do the job.
Before I found the Nimh battery was OK, I also used 2 x12 volt 7Ah batteries successfully, and also a 7 cell Lipo battery from Hobbyking (about £45)
I actually charged it through the output socket of the battery. There seemed to be less chance of shorting. With the 'Warning' label the right way up, positive is on the left, and negative in the middle.
Lithium cells are not tolerant and need special charging conditions, so they need an internal electronic battery management system (BMS). The best way to change is to use the pack content of a lithium battery, but they rarely fit into NiMh cases, so the new battery often has to be mounted elsewhere such as the carrier and wiring to the old connections arranged.
The lithium battery will be 26 volts instead of 24, which won't cause any problem, but you'll also need a new lithium battery charger.
.
Related Articles
-
MTF Enterprises announces acquisition of EMU Electric Bikes- Started by: Pedelecs
-
Wisper 806T folding bike wins Which? ‘Best Buy’- Started by: Pedelecs
-
Sustrans calls for protected cycle lanes- Started by: Pedelecs
-
Amazon launch their first UK e-cargo micromobility hub- Started by: Pedelecs
