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Answered Focus Jam2 battery charging problem

steve_sordy

Wedding Crasher
Nov 5, 2018
8,936
9,281
Lincolnshire, UK
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?
 

Andy A

Well-known member
Patreon
Jan 13, 2019
493
283
North Yorkshire
Well I had my first ride on my Jam2 today but I will run the battery down completely as it does say to do this, then I will know if mine works when it is flat do I need to check any numbers on my charger?
 

steve_sordy

Wedding Crasher
Nov 5, 2018
8,936
9,281
Lincolnshire, UK
Well I had my first ride on my Jam2 today but I will run the battery down completely as it does say to do this, then I will know if mine works when it is flat do I need to check any numbers on my charger?

There are no numbers on the charger. If the green light is flashing, then it is charging. When the battery is fully charged, the green light stays on continuously. If the flashing stops after 15-20 second and the charger switches itself off, then you have the same fault as mine does. Still waiting for a return call from JE James in Sheffield ("The Electric Bike Centre"). I think I'll chase them up right now.
 

mtbphysics

New Member
Mar 13, 2019
8
0
Georgia, USA
I'm glad to have found y'all. I recently purchased a Focus Jam 2 Plus (my first ebike) and have enjoyed it when I can get it charged up enough to ride! I am having the same problem with my charger(s). The first time it happened, the bike shop sent me a replacement charger and it worked one time. Same situation...ran the battery down to red line, went to charge it and charger cycled, clicked a couple of times and nothing. I am leaning toward the thought that the charger can't deal with the battery being run down to red. I initially thought water might be the culprit, but 2 chargers doing the same thing leads me to think the chargers are faulty. Both of my chargers are 4.5v and end in 500 as mentioned. How did your problem get resolved? Any help would be appreciated.
 

mtbphysics

New Member
Mar 13, 2019
8
0
Georgia, USA
My problems seem very similar to those mentioned by Steve_Sordy. Right now, my bike is charging. After taking one of the chargers apart and fumbling with it a bit, it started working again (strange) and I charged the bike. I rode it yesterday but this time brought it home with ~40% battery and when plugged in, took a charge. Same riding conditions (wet, greasy), just a shorter ride. I do not have a TEC pack battery so when charging the internal battery is dodgy, I am out of ebike options. Good thing I still have conventional mtb's!:)
 

stiv674

E*POWAH Elite
Mar 4, 2019
777
600
Wiltshire
Just for reference, my charger ends in 000 and charging output is 4.0A. I've run the integrated battery right down a couple of times with no issues (touch wood ;)) but haven't completely discharged the TEC pack battery yet.
 

Gspot

Active member
Jul 28, 2019
134
22
NW
Just bought a FOCUS BOLD2 with no charger? It was a deal and assumed my shimano charger would work. I could remove the motor and integrated battery to charge with the shimano charger?Does the TEC Pack include a charger? Anyone try a LEVO charger on a FOCUS? Possible?
 

steve_sordy

Wedding Crasher
Nov 5, 2018
8,936
9,281
Lincolnshire, UK
Just bought a FOCUS BOLD2 with no charger? It was a deal and assumed my shimano charger would work. I could remove the motor and integrated battery to charge with the shimano charger?Does the TEC Pack include a charger? Anyone try a LEVO charger on a FOCUS? Possible?
The TEC pack does not come with a charger, but you can buy a charger separately.
The connector on my Focus Jam2 is a Rosenberger connector, like this:
https://www.rosenberger.com/0_documents/de/catalogs/ba_automotive/AUTO_RoPD_Flyer_2016.pdf

If the Levo uses them , you are probably in business. I'd look out for the voltage and current limitations.
 

steve_sordy

Wedding Crasher
Nov 5, 2018
8,936
9,281
Lincolnshire, UK
I can only tell you what is on the charger I have for my Focus Jam2.
I used to have the 4.5A charger, but it gave problems in cold weather, so I switched to a 4A. Here's a pic. The key info is the input and output figures.
Focus Charger 4A.jpg
 

stiv674

E*POWAH Elite
Mar 4, 2019
777
600
Wiltshire
The only physical difference I can see is the Focus charger has two small pins whereas the Levo only has one...

I haven't actually tried either charger on a different bike :eek:
 

JonnyM

Member
Oct 15, 2019
21
9
Cambridge, UK
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 :giggle:), 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. :)
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

Dammit, had by bike 2 days and done 2 rides taking the battery down to 2 bars both times. Now it's not charging, just green light flashes a few times and then stops :(
I left the charger connected with 'no' light for 3 hours (after a call to Rutland Cycles told me it;s not a problem if the light goes out...) and it didn't charge the battery anymore, it was on 2 bars since finishing my ride this morning.
Did a replacement charger sort it out fo you?
* I don't have a TEC pack, just the internal battery.
Thanks :)
 

steve_sordy

Wedding Crasher
Nov 5, 2018
8,936
9,281
Lincolnshire, UK
@JonnyM There is a lot on this forum (Focus section) about this problem, from many perspectives and countries. To answer your final question:

Yes, the 4Amp charger instead of the 4.5Amp sorted the problem, in my opinion. All the evidence said the 4.5Amp charger was the problem. I won't have 100% proof until the cold weather returns.

Despite the urgings of the dealer and the evidence from us both, Focus insisted on changing the frame battery (£600 ish) instead of just swapping the charger (£60 ish). Despite me losing the bike for two weeks, I went along with it to avoid them refusing any further cooperation this coming winter.
I had the same problem with the TEC pack when I let that get cold and low charge, but Focus never offered to replace it. The fact that I had problems with both said to me that it was the charger that was the problem. That and other evidence.
 

Gspot

Active member
Jul 28, 2019
134
22
NW
I would assume no light equals no power. It would 'click' on and then off after a few seconds and then the light would go out a few seconds later. I have a second charger inside and plugged it in. No problem.
 

steve_sordy

Wedding Crasher
Nov 5, 2018
8,936
9,281
Lincolnshire, UK
The charger does not like the cold. Make sure you are charging in a warm environment. Not sure why but I recently had this problem.

Nobody with a 4Amp charger reported any problems, even in really low temperature locations.

The problem is confined to some 4.5Amp chargers, not all. This suggests a batch problem of manufacture, not software. The combination of below 11degC and low battery charge manifests the problem. Keep the battery and the charger above 11degC and the battery above red bars and the refusal to charge does not occur.
But it is still a problem! :mad:
 

steve_sordy

Wedding Crasher
Nov 5, 2018
8,936
9,281
Lincolnshire, UK
I would assume no light equals no power. It would 'click' on and then off after a few seconds and then the light would go out a few seconds later. I have a second charger inside and plugged it in. No problem.

If both chargers are 4.5Amp, it reinforces my view that it is a batch problem, ie some work, some don't. If the charger that works is 4Amp and the one that doesn't is 4.5Amp, it reinforces the view that the 4.5Amp chargers are where the problem is.
 

steve_sordy

Wedding Crasher
Nov 5, 2018
8,936
9,281
Lincolnshire, UK
I am using the 4.5A charger. I did find a 4.0A euro model which is rated 230v. Could I swap the power cord to use in the US?

I believe that your mains voltage is 110V, correct?
In which case the power input will be low by 110/230V, or less than half. So charging will take more than twice as long.
Any electricians amongst you, please correct or confirm. :)

If you have access to a 3-phase supply at 415V, you could tap into two of the phases and get 240V. But you really need to know what you are doing to do that. Health warning!!!
 

Gspot

Active member
Jul 28, 2019
134
22
NW
No, both of my chargers are 4.5A. The first one worked fine until the temps recently dropped. I will swap them to see if the temp is the problem next time I charge. Just received the 4.0A today and will test that as well if it will work with US voltage.
 

Gspot

Active member
Jul 28, 2019
134
22
NW
Yes I believe I would have to tap into an appliance plug. Will need to do my homework. I bought the 4.0A charger in case I started having problems.
 

Damo81

New Member
Sep 8, 2020
5
0
Melbourne Au
I have a Focus Whistler 2 im having a simalar problem after running my battery dead im going to contact the dealer tomorrow and see if i can charge my battery at his store I think my charger is the issue aswell... my battery says its full the bike says its empty... i press the power button on the bike it does its startup thing then flashes on 1 blue dot when i remove the battery from the tube and press the power button on the battery itself it says the battery is full (4 blue dots) the battery charges for about 1 minute then shuts off wtf lol?
 

Damo81

New Member
Sep 8, 2020
5
0
Melbourne Au
I have a Focus Whistler 2 im having a simalar problem after running my battery dead im going to contact the dealer tomorrow and see if i can charge my battery at his store I think my charger is the issue aswell... my battery says its full the bike says its empty... i press the power button on the bike it does its startup thing then flashes on 1 blue dot when i remove the battery from the tube and press the power button on the battery itself it says the battery is full (4 blue dots) the battery charges for about 1 minute then shuts off wtf lol?
 

steve_sordy

Wedding Crasher
Nov 5, 2018
8,936
9,281
Lincolnshire, UK
Take your charger to the dealer and show him. The Law of Sod being what it is, If you use their charger it will work first time.

Use your charger first to demo the problem, then switch to their charger. That will demonstrate that it is the charger.

Or maybe not! I was having my problems in the winter and temperature was an issue. With the 4.5Amp charger when the battery charge was low and the temperature was 10degC or below, the charger would not work. Change any one of those three things and charging began. My problem was eventually fixed by swapping out the charger for a 4Amp version.

When I had taken my bike and charger in to the dealer, they were both below 10degC. The dealer's charger was identical to mine and was at about 20degC. It worked. So frustrating!!!!
 

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