Jam2 Battery Life?

[BammBamm]

I've had my Jam2 for around 18 months now. When I first got it I seemed to get decent mileage out of it, maybe up to 35km before the battery was down to last bar (in trail mode). Lately I've been getting around 16km out of it... I've tried checking the e-tube and stunlocker apps but the info is saying battery health 100% and 0 cycles.

Has anyone else experienced similar with their Jam2?

 

[steve_sordy]

I will assume that you are doing a fair comparison on the trails and not just distance travelled.

I have a couple of possible explanations for you to consider. I am not suggesting that they are "the answer".

Are you riding harder and faster?
Have you put weight on, or carrying more kit?
Have you fitted fatter and/or stickier tyres, maybe with lower pressure?
Are you using Eco less?

I'm sure that other riders will be able to add a few more.

 

[BammBamm]

Thanks steve, you make some good points that I hadn't considered. Have put on a few kegs since I first got the bike so maybe that's it.

 

[BBear]

My Jam2 is also 18 Months old and gets used on average once a week typically using up all the battery and then recharged. I haven’t noticed any significant reduction in battery life so far.
If you’re down by 50% then I would agree it’s likely down to external factors, eg terrain, tyres, weight etc

 

[stiv674]

Is it still taking the same time to charge? If it's charging quicker then it might be a faulty cell.

 

[Blauhassinger]

Hi everybody.
I'm new to the forum, please apologize missing introduction.
I have a Sam2 (almost same bike than Jam2)
After 8000km and 15month my battery need to be replaced.
Trouble started around December 2019.
Noted that 1st bar of the battery indicator vanished much sooner than before.
(I always ride same way to work and back)
At first blamed low temperatures, but end of February couldn't switch on the bike (after charging)
Used ST Unlocker and Emax App.
Both showed 93% battery health.

In the German Pedelec forum you will find some more riders of the Jam/ Sam with similar problems.
I recommend to contact your dealer
Hope this helps.
Stefan

 

[Shy Ted]

I just think that Focus cut a corner on the battery; I’ve been in discussion for months with my dealer regarding range delivered. I took it to a local focus dealer and they said the problem is that the shimano diagnostics won’t work because it’s not a shimano battery i.e. they can’t test the battery element of the system.

 

[BammBamm]

Well that would be really disappointing. After looking at other bikes I settled on the Focus largely because of the Shimano motor. I had trepidation that other brands with their proprietary motors might not be supported into the future.

I like the look of those booz batteries but held off since people already had big delays and now with everything going on... Half tempted to sell the focus while I can and get something with a bigger battery

 

[steve_sordy]

I just think that Focus cut a corner on the battery; I’ve been in discussion for months with my dealer regarding range delivered. I took it to a local focus dealer and they said the problem is that the shimano diagnostics won’t work because it’s not a shimano battery i.e. they can’t test the battery element of the system.

It might not be a Shimano battery, but its a battery fitted by Focus, so the Focus dealer should be more sympathetic. more than that, if the bike is still under warranty, they have an obligation to sort it out.

 

[Winryn]

I would let focus take a look. Doesn’t sound right. I’ve been been riding 37km with 2500ft of climbing consistently ever other day for the past couple of weeks. I’ve been considering a tec pack but I’m unlikely to ever need it tbh as I’m only riding so far due to having to start exercise from home

 

[Blauhassinger]

Hi, the battery is made / manufactured by BMZ a German company ( although I think in reality the battery pack for the focus is made in China).
Whatever, BMZ is also manufacturer for HV battery for the automotive industry. Thus should have good reliability.
On the other side I'm now waiting since 4 weeks for replacement battery.
Hope this helps.
Homepage of BMZ:
HOME

Update: not sure, but I think they also supply the battery for the Specialized Levo models.

 

[Jollyjoiner]

Well where do I start with this one, here goes. I've had my bike nearly 2 years now and done 3200miles on it. I have the tec pack too for those longer rides which I do about once a week. Two or three months ago on a usual route I was losing one bar after 2 miles instead of getting 5 or 6 miles. I took bike to shop for them to do a diagnostic on it and motor fine but the shimano software will not read the focus battery. So after many a email to Focus, and even a phone call to them in Germany the only way to test the battery is to send it back to them and if they think it's fine then they will charge you 100 euro.
I downloaded Stuntlocker free app and when linked to the bike it will just read the battery state and when mine is showing fully charged it is only holding 90% charge so I've lost 10%. I emailed Focus again asking if this was an acceptable amount of battery degradation and they basically said YES.
This is a copy of one of their emails to me. . The battery is to be considered a wearing part, which does not last indefinitely. A loss of capacity due to use and calendar aging cannot be avoided. How long a battery lasts depends on various factors. Depending on care and usage behaviour and battery ageing of the battery, the service life may vary. The so-called cell aging is composed of the calendar life and the cycle life. The calendar life takes into account the fact that the battery gradually loses part of its capacity through storage alone. The exact value depends on the cell chemistry and the average temperature. An average temperature increase of 10 degrees Celsius per year doubles the rate of decomposition and dissolution, resulting in a halving of the service life.

Since there is currently no standardized range determination and numerous criteria influence the range of an electric bike, it is very difficult to make binding statements.

The following factors have a strong influence on the expected range of the e-bike:
- Battery capacity
- Driver weight
- Outdoor temperature
- Wind conditions
- Support mode
- Motor system
- Bicycle type and weight
- Tyre pressure
All these criteria play a role in the possible range and differ on every ride.

Since every system works differently, you can never compare two different systems. Also, each person has a different and individual use of the bike.

If you think that the battery is defective, please contact your bicycle dealer, he can claim the battery and send it directly to the battery manufacturer for inspection.

I hope this make some sense to you, it's took me weeks to find all this info out. .

 

[Blauhassinger]

Hi Jolyjoiner, thanks for your post.
Your story is similar to mine.
Except that my battery is dead now.
It's a shame that the battery from BMZ has such bad performance.
It should be a well engineered product (developed in Germany) but I'm afraid it isn't
On the other side, it seems normal that you loose a certain degree of capacity in the beginning (similar to my experience with electric cars).
But capacity should not fall much below 90%.
Could you please report recently about your battery health
Thanks
Stefan

 

[Jollyjoiner]

Hi Jolyjoiner, thanks for your post.
Your story is similar to mine.
Except that my battery is dead now.
It's a shame that the battery from BMZ has such bad performance.
It should be a well engineered product (developed in Germany) but I'm afraid it isn't
On the other side, it seems normal that you loose a certain degree of capacity in the beginning (similar to my experience with electric cars).
But capacity should not fall much below 90%.
Could you please report recently about your battery health
Thanks
Stefan

Hi ,Stefan
My battery is still charging the 88 to 89%
I'll post up on here if it drops anymore than that. I did manage to get a replacement tech pack battery under warranty as that had an intermittent fault where it would charge but only show one blue light which was the 80% light, think that means some sort of code so that got replaced. Trouble with the internal battery is that it also has lights on it but you can't ever see them.

 

[OldBean]

Is there any more info on this subject ..My internal battery has been showing 4 bars for several months and will only cover 1-2 miles before dropping to 3 bars. when it gets to 2 bars ....it shortly switched to red and will cover approx 2-3 miles. before switching off......Total miles approx 20 with little climbing.
is this new battery time ??..just so happens dealer has one available !! not telling where lbs is