378WH Battery/tec pack problem

Peaky Rider

E*POWAH Master
Feb 9, 2019
821
520
Derbyshire Dales
Has anyone sourced one the original Jam2 batteries (378wh) recently? Mines four years old and is throwing a hissy fit.
Not sure Rutland cycles deal in Focus anymore and neither does the dealer I bought the bike from.
I phoned J E James but seemed to be speaking to a guy who new little about Focus bikes.
 

steve_sordy

Wedding Crasher
Nov 5, 2018
8,361
8,587
Lincolnshire, UK
Try JEJames in Sheffield. They have two numbers, go for the electric bike shop. (ends in 3103)
I bought my Focus Jam2 from them and they were always helpful. They were equally helpful when I bought my latest bike a Merida eOne Sixty.
 

Peaky Rider

E*POWAH Master
Feb 9, 2019
821
520
Derbyshire Dales
I finally made a concerted effort to get a new 378 wh internal battery for my old Jam2.
I contacted J E James again but this time dealt with a guy called Josh.
He gave me a price of £555 with an expected delivery wait of two weeks. The only one I found online was with Ridewell in Italy at around £600, but I am not sure what that included.
Phone call from Josh at James'this morning to say that the battery had arrived, after only one week, with a lower price of £530.

As SS has said many times , first class service from J E James. Thanks Josh.

Just have to now work out how I fit it with the wrist I broke going over the bars on Christmas Eve.
 

EMTB Dude

Member
Nov 16, 2021
50
53
West Yorkshire
I finally made a concerted effort to get a new 378 wh internal battery for my old Jam2.
I contacted J E James again but this time dealt with a guy called Josh.
He gave me a price of £555 with an expected delivery wait of two weeks. The only one I found online was with Ridewell in Italy at around £600, but I am not sure what that included.
Phone call from Josh at James'this morning to say that the battery had arrived, after only one week, with a lower price of £530.

As SS has said many times , first class service from J E James. Thanks Josh.

Just have to now work out how I fit it with the wrist I broke going over the bars on Christmas Eve.
That’s a great result. I’ve bought a few bikes from their Rotherham shop, and bought a Focus external battery from them when I was struggling to find one elsewhere. Always had a good reliable service from them. Hope your wrist gets better soon.
 

steve_sordy

Wedding Crasher
Nov 5, 2018
8,361
8,587
Lincolnshire, UK
Excellent outcome!
Why not get an LBS to fit it? I know from first-hand experience that it is very easy to trap at least one of the wires between the battery and the frame. In my case it manifested itself as an intermittent problem with the display cutting out and the rest of the bike with it. Wiggle the bars and it comes on.... or off. The fix was a new control wire (not a stock item), battery out and back in again, only carefully this time.

That way you can get it sorted whilst your wrist heals. :)
 

Peaky Rider

E*POWAH Master
Feb 9, 2019
821
520
Derbyshire Dales
I think I'll manage Steve. I've had the battery in and out a dozen times since I've had this bike as it has been a right PITA in the reliability stakes.
Over time I have developed several 'hacks' to simplify a fiddly job (too many wires and cables getting in the way and a snug fitting battery).
I just need someone to do the heavy lifting but luckily my wife is at home tomorrow.
 

Peaky Rider

E*POWAH Master
Feb 9, 2019
821
520
Derbyshire Dales
New battery connected and all seems well. The bike powers up as it should and takes charge.:D
I haven't installed it yet as the bike is kept in a non heated garage so I will keep the new battery indoors, snug and warm, until this current sub-zero spell has passed.
The old battery had developed cracks radiating from the two bolt channels but when I opened it up I could not see any obvious corrosion or breaks, so it may have been something more sinister hence the general unreliability of the bike.
Hopefully, this new battery will make my old Jam 2 a little more reliable than it was as it is a great bike and just as much fun, if not quite as capable, as my Rail.
 

steve_sordy

Wedding Crasher
Nov 5, 2018
8,361
8,587
Lincolnshire, UK
...................
Hopefully, this new battery will make my old Jam 2 a little more reliable than it was as it is a great bike and just as much fun, if not quite as capable, as my Rail.
I loved my Focus Jam2. I was sorry to see it go, but I got a great price for it..... and it's only a bike (heresy!!!!)
 

Peaky Rider

E*POWAH Master
Feb 9, 2019
821
520
Derbyshire Dales
Okay, fitted the new battery a couple of weeks ago and everything seemed great. The bike powered on and accepted charge just as it should.
Thanks to my broken wrist, I haven't been able to go on a proper ride yet but thought I'd turn out tomorrow on our usual Saturday ride.
The 378 wh battery isn't sufficient for these rides but I have a TEC Pac and a Trailwatts 252 wh extender. Problem is, neither of these will now connect to the bike. In fact, if the bike is turned on, they actually turn it off when connected.
Apart from the obvious, the wiring loom, does anyone know of anything else that could be the cause of my disappointment.
Sometimes, I just hate E-bikes.
 

Manphred

New Member
Dec 19, 2022
3
1
Brisbane
Hello. Did you find out why the bike turns off when connecting the extremal battery. Mine does the same when connecting the tec pack battery and I thought it might be the external battery.
 

Peaky Rider

E*POWAH Master
Feb 9, 2019
821
520
Derbyshire Dales
I have an E-Booz 252 wh extender, a Trailwatts 252 wh extender and a TEC pac 378 wh extender.
Both the E-Booz and Trailwatts will connect to and power the bike although the Trailwatts throws an EO20 error after a few miles, but then it always has done. I haven't used the E-Booz in anger yet. These two batteries have just the two power cables, pos and neg, connecting to the motor

The TEC pac still fails to power up and will actually turn the bike off when connecting so I'm thinking there might be a problem with the wiring loom, in particular the thin data wires which are not present on the other two extenders, which is why they work.

I don't really think it is a fault with the battery in my case, more likely the wiring loom, but ideally another Jam2 (Mk 1) is needed to test it.
 

Tooks

Well-known member
Subscriber
Mar 29, 2020
416
504
Lincs UK
I have an E-Booz 252 wh extender, a Trailwatts 252 wh extender and a TEC pac 378 wh extender.
Both the E-Booz and Trailwatts will connect to and power the bike although the Trailwatts throws an EO20 error after a few miles, but then it always has done. I haven't used the E-Booz in anger yet. These two batteries have just the two power cables, pos and neg, connecting to the motor

The TEC pac still fails to power up and will actually turn the bike off when connecting so I'm thinking there might be a problem with the wiring loom, in particular the thin data wires which are not present on the other two extenders, which is why they work.

I don't really think it is a fault with the battery in my case, more likely the wiring loom, but ideally another Jam2 (Mk 1) is needed to test it.

I sold my TEC-Pac when it was still new, I used to rarely use more than the frame battery on my regular rides.

I do have a Trail Watts 252Wh bottle pack, and a home made extender as well, and both work fine.

My reason for posting was that I understood you need to have the bike turned off when you connect any extender, and then power the extender up and the bike should spring to life?

If I connect the extender when the bike is powered on, then mine turns off as well.
 

Peaky Rider

E*POWAH Master
Feb 9, 2019
821
520
Derbyshire Dales
That is interesting Tooks and definitely how my Trailwatts works.
I used to use my Tec battery very regularly but don't remember adopting any particular regime to get it to power the motor up.
I haven't really used the Focus for a couple of years as I bought a Rail and it is only because I recently fired up the Focus after replacing the internal battery that I have really bothered with it.
I will have another go with the TEC battery when I get home.
Like you, I find the Traiwatts 252 sufficient for a good ride and preferable to the bulky ugly TEC battery.
On the subject of the Trailwatts extender, does yours ever throw up EO20 (battery to motor connection problem) errors or does it empty without issues?
Thanks for your input
 
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Peaky Rider

E*POWAH Master
Feb 9, 2019
821
520
Derbyshire Dales
Well, just got home and the first thing I did was fit the TEC battery to the Jam 2. and connected the Rosenberg cable.
Pressed the 'on' button on the Tec unit whilst the bike was off as suggested and...............NOTHING:cry:

Sorry Tooks, I didn't remember it having specific requirements to make things work in fact, half the time, I didn't even know which battery was actually powering the motor until enough battery had been used to show on one of the gauges.

Looks like I'll be sticking with the 252s.
 
Last edited:

Tooks

Well-known member
Subscriber
Mar 29, 2020
416
504
Lincs UK
Like you, I find the Traiwatts 252 sufficient for a good ride and preferable to the bulky ugly TEC bat
On the subject of the Trailwatts extender, does yours ever throw up EO20 (battery to motor connection problem) errors or does it empty without issues?
Thanks for your input

I just connect the trailwatts pack to the Rosenberg connector, power it on and the bike powers up. It runs to empty with no errors, as does the home made one I have.

The home made pack is 2 x 5000mAh 5S RC Lipo packs connected in series to give a nominal 36v and 180Wh. They’re connected via a series connector to a Rosenberger connector, and inside a soft toolkit bottle mount bag. Similar footprint to the Trailwatts, and fits in my backpack so I can have an 800Wh setup if I carry both extenders along with the frame battery.

I love my old 2019 Focus, it’s never missed a beat, apart from a dead 4.5A charger, although I’ve probably cursed it now! 😂
 

Manphred

New Member
Dec 19, 2022
3
1
Brisbane
Hi all. My TEC pack bms is on the Fritz. There is 30 good lipo cells connected 10 in series with 3 groups in parallel. Going to get a different bms and rewire it. Will let you know how I go.
 

Peaky Rider

E*POWAH Master
Feb 9, 2019
821
520
Derbyshire Dales
Hi all. My TEC pack bms is on the Fritz. There is 30 good lipo cells connected 10 in series with 3 groups in parallel. Going to get a different bms and rewire it. Will let you know how I go.
Interesting. What makes you think it's the TEC bms rather than the wiring loom?
 

jam2fr

New Member
Apr 1, 2023
1
0
France
Hi!
I have a 2019 Jam² (ex-rental) with the original internal battery + a TEC pack.
I have noticed that the internal battery now only charges up to ~80% / 4 bars (out of 5).
The charger starts "clicking" (relay sound) when the battery reaches ~80%.
It clicks in ~ 10 seconds intervals indefinitely, and alternates between the blinking green ("charging") and solid red ("error") LEDs until I unplug it.
This does not occur when charging the TEC pack.
The "eTuning" apps says the battery is at 89% health and 78% charge. And 0 cycles.

The actual range of the battery also seems to have deteriorated.

Has anyone encountered this? Should I replace the battery?
 

Tooks

Well-known member
Subscriber
Mar 29, 2020
416
504
Lincs UK
Hi!
I have a 2019 Jam² (ex-rental) with the original internal battery + a TEC pack.
I have noticed that the internal battery now only charges up to ~80% / 4 bars (out of 5).
The charger starts "clicking" (relay sound) when the battery reaches ~80%.
It clicks in ~ 10 seconds intervals indefinitely, and alternates between the blinking green ("charging") and solid red ("error") LEDs until I unplug it.
This does not occur when charging the TEC pack.
The "eTuning" apps says the battery is at 89% health and 78% charge. And 0 cycles.

The actual range of the battery also seems to have deteriorated.

Has anyone encountered this? Should I replace the battery?

Batteries do degrade with age and charging/discharging cycles.

The charger will be trying to get the pack up to the correct voltage (ie 100%), some of the cells may not be capable of this now due to deterioration and could trigger the behaviour you’re seeing.

If the bike works though, albeit without the range it once had, you could carry on using it until it becomes intolerable.

A new pack would likely fix it though. 👍
 

merlot

Member
Apr 27, 2021
23
7
ES
I just connect the trailwatts pack to the Rosenberg connector, power it on and the bike powers up. It runs to empty with no errors, as does the home made one I have.

The home made pack is 2 x 5000mAh 5S RC Lipo packs connected in series to give a nominal 36v and 180Wh. They’re connected via a series connector to a Rosenberger connector, and inside a soft toolkit bottle mount bag. Similar footprint to the Trailwatts, and fits in my backpack so I can have an 800Wh setup if I carry both extenders along with the frame battery.

I love my old 2019 Focus, it’s never missed a beat, apart from a dead 4.5A charger, although I’ve probably cursed it now!
Which firmware are you using? After my last upgrade in a Shimano jam2 my diy battery has stopped working
 

Tooks

Well-known member
Subscriber
Mar 29, 2020
416
504
Lincs UK
Which firmware are you using? After my last upgrade in a Shimano jam2 my diy battery has stopped working

I’ll check next time I’m in the shed, but I haven’t updated the firmware since about 2020, if it ain’t broke don’t fix it and all that! 👍😂
 

merlot

Member
Apr 27, 2021
23
7
ES
I’ll check next time I’m in the shed, but I haven’t updated the firmware since about 2020, if it ain’t broke don’t fix it and all that!
4.9.4 is mine and it's about 1 year old. So, probably yours will be a previous one.
 

Tooks

Well-known member
Subscriber
Mar 29, 2020
416
504
Lincs UK
4.9.4 is mine and it's about 1 year old. So, probably yours will be a previous one.
Looks like I’m on 4.7.1.

Thanks for the heads up, I’ll not update in case it no longer works with my 2 range extender packs. 👍

IMG_6351.jpeg
 

Oly

Member
Feb 6, 2021
7
0
San Diego
Hi all. My TEC pack bms is on the Fritz. There is 30 good lipo cells connected 10 in series with 3 groups in parallel. Going to get a different bms and rewire it. Will let you know how I go.
Did you ever have any luck with repairing yours? I had sent mine out to be rebuilt but they couldn't get around the proprietary bms and software needed to power it back up. Living here in the U.S. after Focus has left makes it hard to find a reasonably priced battery. I'm having to shell out about $900 which is hard to do for a bike not worth that much and only 378whr. So very currious how you did and if it's possible. Also wondering if one can bypass all the focus specific electrics and wire a 36v power source into the motor. Spoke to Shimano today and seems no one there has a clue.
 

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