Yamaha Battery/Charger Problem

RayDevon

Just Joined
Oct 29, 2020
1
1
Houston, we have a problem

Haibike sDuro HardSeven SL 2015 Yamaha

Background to the problem

The plug that locks the charger lead into the Yamaha battery has always to me looked a little fragile.

I am lucky to be able to leave my bike in a room at work where I can also plug in my charger.

Some time ago when I returned to the room to ride home I found that the plastic locking mechanism of the plug had broken, probably by the bike being accidentally knocked over by someone who never made themselves known to me although may not have realized that any damage had been done after righting the bike.

Ironically it was probably the fact that the plug locks in place that made it vulnerable to damage when the bike fell over although if it had been a metal plug I do not think it would have broken. Part of the broken locking cap sheared off and remained lodged in the battery charging socket on the battery and remains there still.

I consider myself very lucky to have a room where I can leave my bike to charge at work and decided not to make a fuss about my broken plug. It did make me realize that the plug is definitely not the most robust design.

Anyway I found that the plug could still be connected and the battery charged although no longer held and it could easily fall out.

I use a neoprene battery cover all of the time and when pushed down to partly cover the charging port this helps to hold the plug in place now. It can occasionally fall out now, but mostly works well enough.

About three months ago at home when I tried to attach the charger I found that I could not. I inspected the battery and found that one of the four pins that the charger plug locates into was slightly bent. I very carefully and gently bent it back so I could attach the plug
and charge the battery.

Anyway on Tuesday night last week I got my battery ready to charge and found that the charger light did not come on. When I inspected the battery and charger I found that the pin that had been bent had totally detached which explained why the charging light had not come on.

A separate issue I had with my charger was that wires from the end that connects to the plug became frayed close to where the cable enters the charger inside the outer casing that led to a short circuit and loud bang and a dead charger. Luckily the fuse protected the charger and I was able to use insulating tape to effect a repair and after replacing the fuse it all worked again.

I carry my charger to work with me in my panniers and the connecting wires are wrapped around the charger to put it in a pannier and unwrapped to charge the battery when I arrive at work and this constant wrapping and unwrapping may not have helped.

Now as I have documented I bought my bike from Martin at Ebike shop in Farnham and have had nothing but top notch after sales customer service when I have required it and found them to be a nice and helpful crowd.

So I dragged out my old B bike (2011 Oxygen Emate City) and used that to get me too and from work for the four shifts I had to do making a note to ring Martin to explain the problem and ask for help. What I expected to be able to do was to give Martin the battery and charger to be sent off to Yamaha to have a new plug connector put on the battery and likewise new leads put on the charger and have to pay a reasonable sum for the repair now that the bike is out of warranty.

What actually happened was that I was told that there was nothing that could be done and I would have to buy a new battery, and that he as a dealer cannot open up the battery and would appear to have no facility to get it repaired.

Now I can understand that Martin may not be able to open up the Yamaha battery but I was taken aback that the battery cannot be sent away to be mended. It just does not sit well that a battery I know to be in good shape and that may have lasted a good deal longer has to be ditched just because it needs a new charging plug fitting.

I have been incredible impressed up to now by the quality of the battery after just over three years usage and just shy of 9000 miles. Right up to the time the plug broke it had performed almost like new although the capacity must have been reducing it was not at all noticeable.

I do not think I am the only person to have had this failure but due to my regular use of the bike to commute to work on might be more vulnerable to this sort of mishap.

Of course I could just slap down the cash and buy a new battery and charger for £800 and carry on, but would be very worried that the plug could break again and in so doing right off potentially both the battery and charger.

That plastic locking plug really worries me now and ironically is not as strong as the metal plug on my oxygen and could fail again.

Martin did say that as the battery is out of warranty there was nothing to stop me effecting a repair myself, but I would be on my own.

So fellow pedalec members, what suggestions would you give me in the position I find myself. Do any of you know of someone or somewhere I could approach to effect a repair? Has one of you been in a similar scrape and got out of it? How did you manage it?

What precautions should I take if I have to open up the battery case?

I am going to take it to a mate of mine tomorrow afternoon who used to be a BT engineer and generally very handy to explain the problem. I have the pin that sheared off. The least intrusive repair is probably best, perhaps as simple as a dab of solder to re-attach the pin.

The battery has about a 60% charge so can last a relatively long time without being charged.

In every other regard up to this point Martin and Ebike shop Farnham have provided excellent service.

Maybe I have an antiquated attitude but it seems just plain wrong to ditch a perfectly good battery and charger that just needs a new plug and lead.
My Stand broke whilst it was charging and I had the same problem. Managed to remove broken off male plug from battery socket by drilling a small hole at an angle across the centre (avoiding the pins) and pulling it out with the drill bit. Found powatechnic on EBay, paid £50, sent them the charger on Monday, received it back with a new plug before 9am Thursday. That’s excellent service at the best of times, incredible for a company in a Covid lockdown Area.
 
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georgehenry

Esteemed Pedelecer
Nov 7, 2015
1,447
1,264
Surrey
Hi all with Yamaha battery/charger connector problems. Update on how mine are doing now almost three years post repair.

I started this thread to document a potential disaster when a small metal pin connector at the battery where the charger plugs in broke, and meant I could not charge the battery. I found that this was a problem that could not be fixed by the shop I bought the bike from, or any other. I was told I would need to buy a new battery and charger.

Luckily with help from a technical able friend we managed to fix the problem and replaced the connectors.

It is now almost three years since my connectors broke and my original charger and 400Wh battery are still working really well and have powered my bike for another year and a further 1,326 miles and a total of 4,202 miles since that battery pin connector broke.

As it continues to perform so well It demonstrates the quality of the Yamaha, battery, battery management system and charger, and how wasteful it would have been to be forced to throw them away for the cost of in my case a pair of connectors bought of ebay for under a tenner.

As I have said previously and at the time, I still find it quite disturbing that if you are unlucky and damage the connectors on your Yamaha battery and/or charger there is no support available to get them fixed. You either have to fix them yourself, like I did, which involved overcoming the defeat bolts and opening up the battery case or find a third party business that could do it for you. The normal recommended battery guru, Jimmy at insat surprisingly said he could not when approached by someone else with the same problem.

Other people who had this problem and found this thread have posted how they fixed it providing useful contacts which might still be useful if you have a similar problem with your own Yamaha battery/charger.

Someone else might know whether Yamaha are still using these connectors on their batteries/chargers or have updated them?
 

spiwrx

Just Joined
Jun 5, 2021
2
6
Just had the same problem, roughly 1000 miles on my bike. I think it got knocked over while charging. I tried gluing it, using a bondo type material, all attempts only got me a few more charge cycle before it broke again. After reading this and several other forums I found a nice connector and plug on Amazon to repair mine. Hopefully this lasts. $14 (usd) fix.

This is roughly the same diameter as the original hirose connector, I had to just clear out a flat spot to mount it and bore the mounting hole a hair. Search Cnlinko M12 4Pin Waterproof Connector if you are interested. If I did it again I might get the next larger size, M16, as the wires on the charger were just a few strand too many to fit in the pins, the battery has smaller wire and worked perfect. Also I went in blind and the M12 mounts with 4 bolts and the M16 looks to mount more like the original. The M16 is obviously larger an I cannot verify it will fit as nicely as the M12. M12 seems to have same pin size as original. Also both have
a nice dust cap and simple locking clip.

Went together surprisingly simple.

I forgot yo mention you need a torx tamper/security bit T10H and T8H to crack this egg....

In case its helpful my (US) charger wire color codes / pinout:

Charger | Battery
Yellow | Blue
Black | Black
Red | Red
Blue | White
 

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Last edited:

wheeliepete

Esteemed Pedelecer
Feb 28, 2016
2,047
757
61
Devon
Looks like a neat repair/upgrade from the poor Yamaha item. I bet this has happened to quite a few owners and makes me wonder how many people have been riped off for new batteries and chargers when they are told by the dealer there is nothing they can do to repair.:(
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,968
8,557
61
West Sx RH
Last edited:

georgehenry

Esteemed Pedelecer
Nov 7, 2015
1,447
1,264
Surrey
I started this thread as I was so taken aback that there was no support to rectify an essentially very simple and cheap problem to fix. The Yamaha plug when I had my problem was impossible to obtain.

The good news is that my original 400Wh battery is still going strong, now 4,456 miles and over 3 years after I fixed it.

The more I read pedelec the more I am put of electric bikes that have bespoke control systems/batteries etc that make them difficult/impossible to fix x years down the road.
 
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Nealh

Esteemed Pedelecer
Aug 7, 2014
20,968
8,557
61
West Sx RH
At least with the Yamaha battery charge socket a repair is possible and workable and at least two examples of a repair.
 
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spiwrx

Just Joined
Jun 5, 2021
2
6
That screw fit option is a great idea for those of you less inclined to solder/de-solder. Nice find.
I might just use some form of locktite / threadlock on the battery due to vibration.

I forgot yo mention you need a torx tamper/security bit T10H and T8H to crack this egg....
 

Brier_John

Just Joined
Sep 8, 2021
1
1
Just had the same problem, roughly 1000 miles on my bike. I think it got knocked over while charging. I tried gluing it, using a bondo type material, all attempts only got me a few more charge cycle before it broke again. After reading this and several other forums I found a nice connector and plug on Amazon to repair mine. Hopefully this lasts. $14 (usd) fix.

This is roughly the same diameter as the original hirose connector, I had to just clear out a flat spot to mount it and bore the mounting hole a hair. Search Cnlinko M12 4Pin Waterproof Connector if you are interested. If I did it again I might get the next larger size, M16, as the wires on the charger were just a few strand too many to fit in the pins, the battery has smaller wire and worked perfect. Also I went in blind and the M12 mounts with 4 bolts and the M16 looks to mount more like the original. The M16 is obviously larger an I cannot verify it will fit as nicely as the M12. M12 seems to have same pin size as original. Also both have
a nice dust cap and simple locking clip.

Went together surprisingly simple.

I forgot yo mention you need a torx tamper/security bit T10H and T8H to crack this egg....

In case its helpful my (US) charger wire color codes / pinout:

Charger | Battery
Yellow | Blue
Black | Black
Red | Red
Blue | White

This color code info is what I have been searching the web for. A previous owner repaired the connector wrong and the color code was wrong. I re-terminated the charger and am now charging the battery.
Thank you for sharing this color map!
 
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soundwave

Esteemed Pedelecer
May 23, 2015
16,985
6,533

jijiz

Just Joined
Dec 23, 2021
1
0
Just had the same problem, roughly 1000 miles on my bike. I think it got knocked over while charging. I tried gluing it, using a bondo type material, all attempts only got me a few more charge cycle before it broke again. After reading this and several other forums I found a nice connector and plug on Amazon to repair mine. Hopefully this lasts. $14 (usd) fix.

This is roughly the same diameter as the original hirose connector, I had to just clear out a flat spot to mount it and bore the mounting hole a hair. Search Cnlinko M12 4Pin Waterproof Connector if you are interested. If I did it again I might get the next larger size, M16, as the wires on the charger were just a few strand too many to fit in the pins, the battery has smaller wire and worked perfect. Also I went in blind and the M12 mounts with 4 bolts and the M16 looks to mount more like the original. The M16 is obviously larger an I cannot verify it will fit as nicely as the M12. M12 seems to have same pin size as original. Also both have
a nice dust cap and simple locking clip.

Went together surprisingly simple.

I forgot yo mention you need a torx tamper/security bit T10H and T8H to crack this egg....

In case its helpful my (US) charger wire color codes / pinout:

Charger | Battery
Yellow | Blue
Black | Black
Red | Red
Blue | White
Hi,

Thanks a lot for this trick, I ordered the M12 at https://fr.aliexpress.com/item/32859998459.html. The M16 looks to fit, it's 28mm large but it looked really tight with no clearance for mounting so I took the M12.

Very disappointed about charger price, impossibility to find the original one. Sometimes I don't understand engineers, the connector is so weak for a bike wich may fall, I just walked on the connector and broked it.
 

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