Focus Jam2 (e8000) power problem

Andy.M

Member
Nov 25, 2020
151
90
Rochester UK
Hi guys, not been on for some time but got a major problem today!

Jam2 2019 Shimano E8000 with built in 378W battery.

Went out for a potentially longer ride today. Started off using the TEC external battery. All was well. Eventually the display was flashing red and I made one last assent. At the top of the hill I unplugged the TEC pack and restarted the system on the frame battery. The display worked but showing no bars in the battery. (It is fully charged). After a couple of on and offs tried connecting the TEC pack again. The same thing, the display is on but no (flashing red) bar on the battery charge indicator.

The display still works, speed milage etc and you get beeps when clicking the controller.

Once at home plugged the charger in to see what happens and only get the blue lamp coming on in the switch.

Have not had one issue in three years of owning this bike.

Any ideas???
 
Last edited:

steve_sordy

Wedding Crasher
Nov 5, 2018
8,429
8,668
Lincolnshire, UK
It might be nothing to do with the TEC pack or that fact that you switched batteries. Check the basics, like the connections that you can see. A simple one to check is the connectors at the back of the display. I had one of those get dislodged by a twig when I leaned against a tree. The connector was not loose, just moved enough out of the connection point to have an effect, ie no power! Good luck!
 

Andy.M

Member
Nov 25, 2020
151
90
Rochester UK
It might be nothing to do with the TEC pack or that fact that you switched batteries. Check the basics, like the connections that you can see. A simple one to check is the connectors at the back of the display. I had one of those get dislodged by a twig when I leaned against a tree. The connector was not loose, just moved enough out of the connection point to have an effect, ie no power! Good luck!
Thanks Steve.

The connectors in the back of the display seem fine.

I've taken the 4amp charger out to the garage and it seems like its charging.
Took the 4.5amp charger indoors and connected to TEC pack and it won't charge. So I'll give both a while and see what's happening.
 

steve_sordy

Wedding Crasher
Nov 5, 2018
8,429
8,668
Lincolnshire, UK
How cold is it in your garage? Therre was a problem with some chargers not charging the battery when either (or was it both?) were below 10degC and the level of charge was low.

Warm chargers and or battery worked. So, bring both into the house for a test. Let them warm up.
 

Andy.M

Member
Nov 25, 2020
151
90
Rochester UK
How cold is it in your garage? Therre was a problem with some chargers not charging the battery when either (or was it both?) were below 10degC and the level of charge was low.
Yes its cold today. Only had a non charging problem once but I always wait for the click and the green flashing light before leaving it. Years ago I bought a spare 4amp charger (the better one) in case of any future problems. It appears to be charging out there so I'll give it a while and go have a look, fingers crossed.
 

Andy.M

Member
Nov 25, 2020
151
90
Rochester UK
Update for anyone stumbling upon this thread.
It was definitely a faulty charger, the replacement one charges the batteries just fine.

Wonder if I can get it repaired?
 

Tooks

Well-known member
Subscriber
Mar 29, 2020
427
516
Lincs UK
Update for anyone stumbling upon this thread.
It was definitely a faulty charger, the replacement one charges the batteries just fine.

Wonder if I can get it repaired?

My original 4.5A charger failed after only a few weeks from new, whilst I was awaiting a warranty replacement I purchased another from an online shop. It was a 4A one that turned up, and I’ve been using that one ever since and it’s been fine in over 3 years. I’ve still got the replacement 4.5A one as a backup but have used it on and off without issue.

Derby Cycle did seem to have a problem with some of the chargers early on.
 

Peaky Rider

E*POWAH Master
Feb 9, 2019
824
521
Derbyshire Dales
Would a faulty charger cause all the symptoms you describe in your opening post? Why didn't your internal battery connect when switching from your TEC battery whilst out on your ride? I doubt that, even if the internal battery had not fully charged when you thought it had, that it would be completely empty.

I ask because I have the same bike as you. Unlike you, I have not had years of trouble free riding, in fact quite the opposite and have a real love hate relationship with my Focus.

After resuscitating my Focus many times following power failures it finally died the death of all deaths and needed a new battery to bring it back to life. Everything seemed perfect with the new battery fitted until I connect the TEC battery and then everything dies so a new wiring loom might now be needed.

The battery and wiring are definitely the week point with this bike and, in my experience, can play all sorts of silly games to spoil your ride.. I would love to hear how you get on from now.
 

Andy.M

Member
Nov 25, 2020
151
90
Rochester UK
Would a faulty charger cause all the symptoms you describe in your opening post? Why didn't your internal battery connect when switching from your TEC battery whilst out on your ride? I doubt that, even if the internal battery had not fully charged when you thought it had, that it would be completely empty.

I ask because I have the same bike as you. Unlike you, I have not had years of trouble free riding, in fact quite the opposite and have a real love hate relationship with my Focus.

After resuscitating my Focus many times following power failures it finally died the death of all deaths and needed a new battery to bring it back to life. Everything seemed perfect with the new battery fitted until I connect the TEC battery and then everything dies so a new wiring loom might now be needed.

The battery and wiring are definitely the week point with this bike and, in my experience, can play all sorts of silly games to spoil your ride.. I would love to hear how you get on from now.
The charger is definitely junk. The spare one has charged both batteries.
I think I have now worked out what happened.
Every time I get back from a ride, usually using the frame battery, the bike is left in the garage plugged in to the original charger that is kept in the garage.
I always wait a few seconds for a click and the flashing green light indicating charging is taking place. Then leave it until the next day usually.

So two rides ago I get back home with the last red bar showing on the display so I plugged it in, wait for green light and leave the bike. The next morning I look in the garage and the charger has switched off as usual after fully charging. Only this time I suspect that the charger had decided to break. So unbeknown to me the battery is still (almost) empty.

Next ride I think I'm going on a longer ride so fit the TEC battery that I keep indoors and had charged it ready using the spare charger indoors. I start the ride with the TEC plugged in thinking I will switch to the frame battery when required.
The TEC battery made it to a flashing red bar, so I unplugged it then.

I press the start button and the display lights up but with empty battery indicator. Everything seems to be there including beeps when you click the controller but no power mode can be selected.
I then plug the TEC back in and get the same thing, empty battery display, no power.
Cycling along and the speedo and odo are still working.

My assumption is that there is enough juice left just to power the display only, but not enough voltage for the bikes ecu to fire up any form of pedal assist power. As both batteries were in the red zone I assume thats why nothing worked for both of them at that point.

Hope that all makes sense. If anything else occurs I will update you.

I realise I may have been lucky with my bike. Had it for 3 years now, 1800 miles, and the only issue I can think of is after I washed the bike once, the connectors must have been wet and the charger did throw up a red error lamp. Drying the connectors off cured it and I've never had a repeat of that.
 

Peaky Rider

E*POWAH Master
Feb 9, 2019
824
521
Derbyshire Dales
That's a mysterious chain of events and whilst one of your chargers might be cream crackered I think you may have identified the real problem in your last paragraph, washing your bike.

My Focus hated water, especially from a hose pipe. I know people will say 'don't use a hose pipe' but sometimes it is the only way.

Hope your luck holds but maybe plug those stupid great vents where the cables enter the downtube, I have.
 

EMTB Forums

Since 2018

The World's largest electric mountain bike community.

523K
Messages
25,822
Members
Join Our Community

Latest articles


Top