Answered Focus Jam2 battery charging problem

[steve_sordy]

The bike is a Focus Jam2 2019, only had it a few weeks. Very recently I discovered that the battery needs to be run down until it goes into sleep mode before fully charging.

As per the manual I ran down the integrated battery today. I was on Trail and the range went to zero and a mile or so later, it changed into Eco and the display went to red. I kept going for about another mile and the battery switched itself off. The display was still functioning, but no pedal assist. I switched over to the spare battery from the TEC pack and carried on.

When I got home I removed the spare battery and then put the integrated battery on charge. As expected, the charging light flashed green on/off on a 2 second cycle. But after about 30 seconds it stopped flashing and went out, no charging lights at all.

According to the charger manual, If the battery has less than 25V, then the charging current starts with 500mA for half an hour. When the 25V s reached, the charger will switch to fast charge.

I have left the charger connected and switched on for two hours now. At intervals I have switched off the charger and back on again. The same cycle repeats, ie flashing on/off for a short while and then going dead, ie no lights at all. I removed the charger from the bike and switched on the bike as normal to see if it had been charging anyway, it hadn't.

Prior to this the battery charger had worked as normal. In fact I have just tried charging the spare battery and everything worked as normal.

Any suggestions as to what I can do to fix this. Or have I done something wrong by running the battery past the red until it switched itself off?

 

[DAZ1925]

I have a 2018 model and on a recent ride I've run down the battery until only the display was working as you did. Unfortunately I have no additional battery but I only had short distance to do to complete my ride. afterwards I charged my bike to 4 bars on the display with no issues.

 

[highpeakrider]

I can only see mention of running down the battery in the TEC pack manual.
Can’t see that anywhere for the internal,

This is to perform the learning cycle.

As soon as the battery enters sleep mode press the power button for one second.

Did you do that?
It says perform every 6 months.

Have you tried disconnecting the charger and pressing the power button and looking for an error code?

 

[steve_sordy]

I can only see mention of running down the battery in the TEC pack manual.
Can’t see that anywhere for the internal,

This is to perform the learning cycle.

As soon as the battery enters sleep mode press the power button for one second.

Did you do that?
It says perform every 6 months.

Have you tried disconnecting the charger and pressing the power button and looking for an error code?

Your points in turn:
Nope, I couldn't find it either when I first looked, but I found it today in the "TEC Fur Shimano Steps E800" - "Original User Guide Pedelec". Section 7 Battery, 7.1 Safety Information (which is why I didn't find it the first time ), in the section marked in green as IMPORTANT on page EN-47.
The bike shop (JE James in Sheffield "The Electric Bike Centre") didn't tell me about the learning cycle, I only found out about it when I was reading the TEC pack manual. I am trying to do the learning cycle for the first time!

By "power button", do you mean the blue on/off switch on the top tube? I'll assume that you do.

No, I did not do that when the battery first switched itself off. I'll go have a go now......
Nope, tried it in a variety of ways and with different timings. All same result.

 

[MattyB]

If the charger charges the TEC pack successfully but not the main pack then it must be a battery issue. Don’t worry about it being your fault though - the BMS is designed to protect the battery from damage through overcharging or over-discharge, so if that is the issue it’s a stone cold warranty job (especially given you were following the destructions! ). I guess you just got unlucky.

 

[steve_sordy]

..........especially given you were following the destructions! )............

"Following the destructions". That is how it feels right now.

 

[highpeakrider]

Does it turn on if you connect the TEC pack Steve?

 

[highpeakrider]

Seem to remember I had this with mine but the connection wasn’t seated correctly, if you turn the bike over have you got any dirt on the connectors from using the TEC pack?

 

[bissona]

We had a few issues along these lines in the first few weeks, but came to the conclusion that they were mostly down to washing and a lack of WD/grease in the 'leccy bits. For a while I had to bounce mine on the back wheel repeatedly to get the bloody thing to turn on!

If all else failed it would always work after a night in a warm place, hence the attention to electrics. Since application of the right gunk all has been fine, but very occasionally they give us grief, and the most reliable way to sort it has been repeatedly attach/detach the charger and keep trying the power button at the same time.

 

[Macone]

I use mine for all sorts of riding including long road rides with mates. Commonly run either my integrated battery or Tec pack down to "Full Red" until they cut out, then change to the other battery and carry on (I alternate which battery I start riding on). Have had zero problems charging either battery under these circumstances. about 1700km's so far.

 

[steve_sordy]

Does it turn on if you connect the TEC pack Steve?

I rode the bike for 5 miles with the TEC pack on. After removing the TEC pack, I cleaned the connector area before connecting the charger. The charger powers the TEC pack just fine. The charger just will not function on the integrated battery.

Or did you mean connect the TEC pack to the bike and then try charging? Whether you meant that or not, I'll try it tomorrow morning. Good idea, at least it will rule out something, not sure what yet but I'll know once I've had a night's kip.

 

[steve_sordy]

We had a few issues along these lines in the first few weeks, but came to the conclusion that they were mostly down to washing and a lack of WD/grease in the 'leccy bits. For a while I had to bounce mine on the back wheel repeatedly to get the bloody thing to turn on!

If all else failed it would always work after a night in a warm place, hence the attention to electrics. Since application of the right gunk all has been fine, but very occasionally they give us grief, and the most reliable way to sort it has been repeatedly attach/detach the charger and keep trying the power button at the same time.

Thanks Bissona, I'll check again that the vital bits are all clean. I have not used any water dispersant (spray or grease) yet but I will strongly consider it.

 

[steve_sordy]

I use mine for all sorts of riding including long road rides with mates. Commonly run either my integrated battery or Tec pack down to "Full Red" until they cut out, then change to the other battery and carry on (I alternate which battery I start riding on). Have had zero problems charging either battery under these circumstances. about 1700km's so far.

Well, at least I now know that I wasn't doing anything wrong! Many thanks for that!

 

[steve_sordy]

Does it turn on if you connect the TEC pack Steve?

First job was to check the cleanliness of the charging socket on the frame. I used a high power torch and had a good look. It was spotless, as was the connector on the charger.

I refitted the TEC pack and then connected the charger to the TEC pack. It charged as normal. With the TEC pack still in place, I re-connected the charger to the bike frame. Same old problem.
Another thing I checked was the connection of the charger to the mains. It was firm, and in any case it charged the TEC pack OK (clutching at straws here).

 

[bissona]

Thanks Bissona, I'll check again that the vital bits are all clean. I have not used any water dispersant (spray or grease) yet but I will strongly consider it.

I think part of the problem may be the big air ducts at the top of the downtube. The water floods down there, past all of the connections that sit under the battery. When you slot the battery back into the downtube so have a choice of where to route the cables, and I'm guessing some of them could get flooded during even a relatively light wash.

It's slightly bizarre that I never had an issue while riding, even in torrential rain / through deep puddles, but did get problems after careful washing. Either way, no issues for a few months now following a major WD/grease session. Good luck getting yours sorted.

 

[steve_sordy]

I think part of the problem may be the big air ducts at the top of the downtube. The water floods down there, past all of the connections that sit under the battery. When you slot the battery back into the downtube so have a choice of where to route the cables, and I'm guessing some of them could get flooded during even a relatively light wash.

It's slightly bizarre that I never had an issue while riding, even in torrential rain / through deep puddles, but did get problems after careful washing. Either way, no issues for a few months now following a major WD/grease session. Good luck getting yours sorted.

You correctly identify the air ducts (a uniquely Focus design feature I believe), but there is no "when you slot the battery back into the downtube so have a choice of where to route the cables...." Well not this "you" anyway! It's a major job to remove the battery from a Focus, were you referring to the bike builder or maybe the LBS workshop guy?

Before purchase, I asked the LBS about rain entering the ducts, along with any other crap. He said that the water just runs out of the bottom of the down tube as it is designed to do, so don't cover the slots in the motor cover! At this point the workshop manager chimed in that he removed the motor cover once that had been "sealed" by the owner and a load of mucky water ran out! Once it had all been cleaned and dried out, it worked fine again.

 

[steve_sordy]

Hmmm, no call from the LBS as promised. It must be a harder problem for them to diagnose than they thought. JE James in Sheffield ("The Electric Bike Centre") is where I got the bike. I expected them to be experts on the ebikes they sell, but it seems not. Three times now they have had to ring me back after they "do some research". And if it is so important to battery life, why didn't they tell me about the "Learning Cycle"?

 

[MattyB]

Hmmm, no call from the LBS as promised. It must be a harder problem for them to diagnose than they thought. JE James in Sheffield ("The Electric Bike Centre") is where I got the bike. I expected them to be experts on the ebikes they sell, but it seems not. Three times now they have had to ring me back after they "do some research". And if it is so important to battery life, why didn't they tell me about the "Learning Cycle"?

I doubt very much this learning cycle is important to battery life. How and when you charge and store the battery definitely is, and how hard you discharge it, but this learning cycle stuff... it certainly doean’t align with anything I’ve read about handling lithium batteries. Probably just to keep the BMS in sync with the SOC of the pack after lots of partial charges.

 

[steve_sordy]

I have been thinking.... (it happens from time to time).

Despite the charger not working on the integrated battery but OK on the TEC pack, suggesting that the charger is OK, I'm no longer so sure.

The charger I was supplied with is by a company called BMZ. It is supposed to detect voltages below 23V and trickle charge at 500mA for 30 mins. Only when the voltage is at or above 23V will the full charging current come on. What if the charger has a fault in the low voltage detection and just doesn't come on at all? That way it would work fine on a partially depleted battery but not a fully depleted one. Flashing green lights are evidence of charging taking place, it is not a fault.

Also, the Shimano manual shows a different type of charger (a Shimano one) to the one I've got and it says that a flashing light is evidence of a battery fault.

Which type of charger have you guys got?

It looks like more topics for discussion with JE James.

 

[highpeakrider]

Not sure what mine is not at home, mine just always flashes green with the bike light on.

 

[bissona]

but there is no "when you slot the battery back into the downtube so have a choice of where to route the cables...." Well not this "you" anyway! It's a major job to remove the battery from a Focus, were you referring to the bike builder or maybe the LBS workshop guy?

Simple enough job, takes about 30 mins to drop the motor off / battery out and another 30 to put it back. We've done it twice and, apart from getting the sodding battery in/out of the downtube (there's a very irritating lip in the casting), it's a doddle. Everything is well engineered and you can do the whole job without specialist tools (although a spider tool would speed things up a little).

If you're getting no joy at your LBS then you may have to try further afield. We ended up taking one of ours on holiday in pieces before finding a great French dealer who gave us the battery from his own bike in replacement for one that had suffered a very watery trauma...

 

[bissona]

Which type of charger have you guys got?

One like this:

Battery charger for Shimano integrated batteries E-bike Battery and Charger, E-Bike Charger FOCUS

You may struggle to get an exact answer from anyone on this, knowledge is in short supply no matter where you look. We had a Focus factory electrical engineer on the phone swearing blind that you could ride the bike entirely without an internal battery, just with the TEC pack, but that was proven false when our friendly dealer tried exactly that. There are an additional two wires coming off the internal battery that we have deduced turn the motor on/off, and the section of the loom that goes to the TEC pack / charging point does not have these wires.

Given that you can still ride with the TEC pack, your BMS / bit-that-switches-on-the-motor must still be functioning in the internal battery, so it can't be completely dead. As you say, that would point to something stopping the charger from charging your internal cells from their very-low state.

There are five key components to the whole system;

1. Charger
2. Battery
3. Motor
4. Loom
5. Display (I'm not 100% sure any display is even required to run the system, but it does help to be able to see what's going on!)

If you can try swapping those for ones you know function (anyone close to you with another Focus?) then it shouldn't take long to find the culprit. Getting replacement parts, however, is another thing entirely, but Derby (who own Focus) are reliable if not very speedy. We have a spare loom we could send you, but doesn't sound like that's the issue here.

 

[steve_sordy]

@bissona That is very similar to mine. It has the same charging display but the display is in the centre not off to one side.

It needs confirming, but I still suspect that the charger is switching off when it detects the low battery voltage rather than trickle charging. It would explain what is happening and has the advantage of a quicker and faster fix than having to take my bike back on a 2hrs 40 mins round trip (twice), so I could be biased! I could use someone else's charger just to check, or maybe one at a much nearer Focus dealer.

Who's got a Focus and lives nearer than 40 miles to Grantham?

 

[R120]

The Shimano manual will refer to generic Shimano components - because the Focus uses a different battery ( As you say BMZ, who are a very big company and one of the market leaders, out of Germany) it uses a different charger.

It would seem the issue is with the built in battery, as IIRC the TEC pack plugs into the charging port on the bike, so if you can power the bike with the TEC pack then I would guess that works?

 

[highpeakrider]

Not unless Whaley Bridge is closer, I don’t think so. JE James chesterfield?

 

[steve_sordy]

The Shimano manual will refer to generic Shimano components - because the Focus uses a different battery ( As you say BMZ, who are a very big company and one of the market leaders, out of Germany) it uses a different charger.

It would seem the issue is with the built in battery, as IIRC the TEC pack plugs into the charging port on the bike, so if you can power the bike with the TEC pack then I would guess that works?

Yep, the bike works with the TEC pack plugged into the same port as the charger plugs into. I agree that at first sight it must be the integrated battery that has the problem because the charger works fine on the TEC pack. That may indeed be the problem, but an alternative explanation is that the low voltage sensor on the charger may be faulty. I can rule that out by using another charger. I will attempt to locate one and try charging the integrated battery.

 

[steve_sordy]

Finally, an answer!

I phoned Rutland Cycling, my nearest Focus dealer and asked them if I could bring my bike in and borrow one of their chargers for five mins. They said yes and off I went.

Their charger started charging the frame battery and carried on doing so. The workshop guy suggested I go for a wander around the store while the bike charged. 15 mins later the bike was still charging and was up to two bars on the bike display. Success! Oh happy day!

The charger looked identical to mine, so I don't know why I checked but the model number was slightly different (ending in 000, whereas mine ended in 500). In addition the max charging current was 4.0A, whereas mine is 4.5A. I have no idea whether this difference is significant, or that I just have a faulty battery. When I got home I plugged in my charger and it is happily charging away, now the frame battery is not completely discharged.

I contacted JE James, who had been busy trying to find reports of a similar fault (without success). I gave them the good new-bad news routine. "Good news, it's not the frame battery, bad news it is the charger." I told them about the different model numbers and left them to sort out a warranty claim. When they get a new charger in they will post it to me. There is a good chance they won't want the current one returned.

PS: Big thanks to Rutland Cycles who gave me their time willingly and without charge.

 

[steve_sordy]

To continue this story. I decided to run down the TEC pack today, but not all the way like I did the frame battery. I just ran it down until the 1st bar went red. Previously I had run down the frame battery until it switched itself off (and it then wouldn't charge up).
Not enough caution! The TEC pack battery would not charge either. I know the charger is at fault and that it will be replaced under warranty, but it seems that it is even less tolerant of a low battery than I thought.

 

[jonnie brads]

When do you get your new charger?

To continue this story. I decided to run down the TEC pack today, but not all the way like I did the frame battery. I just ran it down until the 1st bar went red. Previously I had run down the frame battery until it switched itself off (and it then wouldn't charge up).
Not enough caution! The TEC pack battery would not charge either. I know the charger is at fault and that it will be replaced under warranty, but it seems that it is even less tolerant of a low battery than I thought.

When does the new charger come ? I have not depleted the battery yet so have not come across the problem (hopefully I dont) but trying to avoid it would you suggest not depleting the battery till it stops ? Or wait till your new charger comes and see if the serial number is the same as mine and not worry about it. I'm new to the ebike scene so excuse the noon questions. Thanks ?

 

[steve_sordy]

When do you get your new charger?

.........I have not depleted the battery yet so have not come across the problem (hopefully I dont) but trying to avoid it would you suggest not depleting the battery till it stops ? ..........

If you have a charger with the same fault as mine, then the sooner you find out the better! Sooner or later you will deplete your battery, whether by design or default. Then what will you do