Focus Jam/Sam Battery Life query

[Bri-72]

Wondering what others experiences of the stock 378ah battery is. And also comparisons with other systems.

Most of my riding is steep up and descents. Finding about 3000 feet of ascent total and 10-20 miles is about the limit. 2 hours riding and battery done.

Not unhappy with that, and realise the battery is 25% smaller than other bikes. But I then see reviews of Levos doing all day rides and 40 miles rides. Is that for real? Or only on very flat terrain?

 

[steve_sordy]

I have ordered Focus Jam 2 so I am interested in this thread. Out of interest, are you a heavy rider and do you use boost a lot? I'm 14.5 stone in my riding kit (203 lbs and 92kg).

 

[Bri-72]

It’s the Jam 2 plus Ive got. Fairly recently so only 5 or 6 rides so far. I’m 15 stone and it’s fitted with 2.8 magic Mary tyres which are very draggy. So realise none of that helps.

Don’t use boost find its more power than I’d ever need. Eco mainly and use trail mode sparingly only on real steep ‘granny ring’ style climbs. I mainly use it for a enduro type downhill trails rather than long xc stuff.

So it does the 2hour runs I need and bought it for. Just a bit disappointed even when less ascent involved, range at best I might eeek out to 3 hours/25 Miles.

 

[steve_sordy]

I would hazard an uniformed guess that using up the battery almost completely each time and then fully recharging will extend its life, or at least get the most miles out of the number of charges you will be "allowed" to do.

 

[Bri-72]

Still really like the bike and in terms of spec I couldnt justify near twice the price for a levo. Hope you enjoy yours when it comes.

 

[MattyB]

I would hazard an uniformed guess that using up the battery almost completely each time and then fully recharging will extend its life, or at least get the most miles out of the number of charges you will be "allowed" to do.

Not really. There is no negative to partial charging, and no memory effect associated with Lithium based cells. However storing them at an elevated state of charge (above 80% capacity for lengthy periods) will increase internal resistance and decrease cycle life. Best recommendation is to charge to 50% after a ride, then top up the night before you go for a full ride.

 

[Bri-72]

I follow what you’ve said, which follows the shimano advice to not store fully charged. but does that not then mean twice the number of charging cycles to achieve full charge? Which itself is detrimental to battery life.

 

[MattyB]

I follow what you’ve said, which follows the shimano advice to not store fully charged. but does that not then mean twice the number of charging cycles to achieve full charge? Which itself is detrimental to battery life.

No, a charging cycle is from fully flat (well, as flat as the onboard battery management circuit will let it get anyway) to fully charged. Following the regimen above still results in one full cycle; you are just doing it in two halves, one after your ride and the second just before the next.

 

[bissona]

We've found range is hugely impacted by so many variables that even theoretically-comparable stats are largely meaningless. Weight, temperature (of ride, and of bike before ride), climb, tyre pressures, modes/aggression, etc, all play a huge part.

Ultimately, the battery capacity is undoubtedly as claimed, and there is no reason why the efficiency of the Shimano system should any different in Focus than in any other brand, so range should be similar to other Shimano-based bikes. How that compares to other drivetrains is open to discussion, but I'm not hearing about any of the manufacturers using drastically different technology, so would be surprised by big differences in efficiency.

We tend to keep the JAMs warm before a ride (I sometimes move mine into the hall the night before) and give the battery a last-minute top-up (a variation on the MattyB 50/50 process above) to ensure its truly full. As we have two near-identical ones I can confirm that range is spookily similar on both, even with differences in style. This has been the case across at least 30 rides this autumn.

Did about 35 miles of aggressive-but-70%-flatish terrain in cold temps on Sunday and saw the whole display go red (just after range hit 0km) about 50m from home. Turned it off and dragged her the last few metres!

 

[Bri-72]

Thanks for feedback. Temperature may be a factor too, not but much above zero for past week or two.

 

[steve_sordy]

When I was at the Rutland Cycling demo day earlier this month, a lot of riders there were trying eBike for the first time. Consequently there were a lot of questions being asked. Predictably, one was "how many times can I recharge the battery and doesn't it degrade?" etc. One reply given by the Giant rep was on the lines of.... "These batteries don't have a hysteresis lag, so you can charge it as little or as much as you like, partially or fully without affecting the battery life. However, the contacts have a life and they degrade by a tiny amount each time they are used, so it's better to give fewer but larger charges."

OK, that will not be verbatim, but I've got the sense of it. It became my turn for a bike, so I never heard any more. But I'm not sure what to think about the contacts degrading bit. It sort of has the ring of truth about it, but how critical is it - a little bit, not much at all, complete bllx....?

 

[MattyB]

My view is that the rep in question does not know a lot about lithium batteries...

When I was at the Rutland Cycling demo day earlier this month, a lot of riders there were trying eBike for the first time. Consequently there were a lot of questions being asked. Predictably, one was "how many times can I recharge the battery and doesn't it degrade?" etc. One reply given by the Giant rep was on the lines of.... "These batteries don't have a hysteresis lag, so you can charge it as little or as much as you like, partially or fully without affecting the battery life.
All batteries have a useful life that is determined by how the pack is charged, stored (including state of charge and temperature) and discharged. They are right in that charging from charging from 0-50% and then 50-100% won't make any difference in terms of charge cycles the battery can sustain, but leaving it at 100% for an extended period absolutely will kill capacity and reduce it's useful cycle life. Nissan know all about this from the issues experienced with the Leaf initially.

https://batteryuniversity.com/learn/article/what_causes_lithium_ion_to_die

Battery Capacity Loss – Electric Vehicle Wiki

However, the contacts have a life and they degrade by a tiny amount each time they are used, so it's better to give fewer but larger charges."
Twaddle. The contacts on your ebike should last far beyond the life of the battery providing you keep them clean and dry. Degradation through charging is going to be tiny compared even a relatively short period with water/dirt present. Basically keep those contacts clean and you will be absolutely fine.

OK, that will not be verbatim, but I've got the sense of it. It became my turn for a bike, so I never heard any more. But I'm not sure what to think about the contacts degrading bit. It sort of has the ring of truth about it, but how critical is it - a little bit, not much at all, complete bllx....?

 

[Lad]

I get a red bar on battery in around 60km distance mark -> 70% ECO, 25% TRAIL, 5% BOOST. Shifting a lot to keep cadence at 80 +/-5 where my personal sweet spot is. Not an aggressive rides but not just cruising either. Not bad for 375W battery IMO.

 

[Bri-72]

What sort of ascent over that distance? As that’s an impressive distance.

 

[Macone]

42km, approx. 500m ascent, 116kg (plus the bike), Sealed surface, all in trail mode (unmolested), then got full "red" and lost power. (I then changed to my second battery and carried on). Don't know if that helps or not but that's what I got out of the first battery.

 

[Lad]

What sort of ascent over that distance? As that’s an impressive distance.

One of the locals trails, 3 laps, max delta elevation ~120m. 85kg fully kitted rider, bike (Bold) is 18.3 kg with pedals, fair bit lighter than alu Jam/Sam.

I think it would be doable for Shimano to include in the firmware a percentage of use for each mode. Memory is there, could be just three numbers, or more fancier bar or pie chart (blue, green, yellow).
I personally don't care much about max and average speed. For me, a Cadence display is on most of the time.

 

[highpeakrider]

Took mine out today, sat all night in unheated garage, charged in the morning and did my usual 16 mile ride.
It’s about 0 degrees with a bit of snow, saw no change in the battery usage at this temp.

 

[steve_sordy]

Very recent buyer of a Focus Jam2 9.6 NINE. Bike weight 20.4kg, my riding weight 92kg. Had it about a fortnight. (Note for non Focus riders, the battery is 378Whr).

On Friday I read the manual that came with the TEC pack it said that the battery needs to be ridden until it is flat first and then fully charged. And then that this must be repeated at six month intervals. Interesting, as this is not mentioned in the battery section in the manual that comes with the bike! Because I'm sure that they are both the same battery, just different shapes, why the different advice? So I rang the dealer. He told me that a) I was the first person to have ever asked him this question, and b) he had no idea. He rang me back an hour later to say that he'd read up on it and that it seemed like sensible advice from Focus for both batteries.

So today, I went out with the intention of fully flattening the integrated battery. I carried the spare to get me home. I failed to flatten the battery, didn’t even come close!!
The air temperature was between 3-5 degC for the duration of the ride.

Before setting off, the Range was 40miles in Eco, 30m in Trail and 20 in Boost. The route was mainly tarmac, but took me up the steepest hills around here, which admittedly are not steep but go on for a mile or so. About 8 miles of the route is an old railway bed with part of it in a cutting. Twice I rode up the sides of the cutting to see what was there which required Boost. I left the tyres at 16psi front and 18psi rear; why help reduce rolling resistance? I wore my normal kit.

I set off in Boost, with the intention of keeping it there to drain the battery as fast as possible. The first "problem" I noticed was that I was perfectly capable of keeping the bike above the cut off speed without any pedal assist, so no battery drain going on there! I reverted to Eco, so at least I could see when the pedal assist was kicking in, even if I couldn't feel it. I noticed that although I couldn't feel the pedal assist, it must have been helping me because I didn't expect to be able to maintain that speed on a bike of that weight with those soft tyres (Maxxis Rekon 3C 29x2.6 front and rear). But whenever I came to a hill that took me below 16mph, I engaged Boost. Once or twice, when I was in Eco and above the cut off speed, I switched the motor off and I couldn’t feel any drag. My speed did not change until I came to an up incline, upon which I engaged Eco again, felt a brief kick and settled in again at just above the cut off speed.

I haven’t done this ride for years because it’s mostly boring tarmac, but my concentration on the “e” aspects converted it a ride of interest. I started off wanting to flatten the battery, but part way through I started to wonder just how far I could go on this bike!

I did 20 miles and ended up with range figures of 22m in Eco, 16m in Trail, and 11m in Boost. So they were all better than half the range forecast at the start, despite doing exactly half the initial forecast Eco range.

I confess to being puzzled by these figures. For a lot of the ride I was above the cut off speed, so I was expecting the range figures to be higher than I ended up with. The use of Boost must be penal on the battery life.

My main out take from this is an increase in confidence about how far I can go on the battery. The lack of drag of the Shimano Steps motor that I experienced on the test ride is well and truly confirmed. Either “off”, or “on” but after the cut off, the lack of drag is the same.

 

[bissona]

Before setting off, the Range was 40miles in Eco, 30m in Trail and 20 in Boost

We've found that the range forecasts can be fairly heavily skewed by recent activity, but they settle down after a few mins of steady pace. Short steep hills are the worst, have caused a few moments when close to the 'red-zone'!

That said, range forecasts from the moment you turn it on should be pretty accurate. It would be good to know the sampling period (cue another evening of googling...).

 

[OldBean]

After 6 months of riding gentle Suffolk rolling hills I easily get 35miles out of my Jam 2 ltd , I am 65kg and ride in eco and off where appropriate. With Trail and Boost as necessary.However do try to,keep off road where-ever possible (75%) Recently just got back to base in the Red with 34 miles on the clock...not bad on the small battery.
I find I want to ride further each outing so now need the expensive TEC pack
Be interesting to see what the cold snap will do to range as my Focus is kept,in unheated garage....STMBO would frown should I bring it inside ....well as long as she does not throw something its worth it!
Have fun. ..PS dont like riding this icy stuff with knobbly tyres! Feels distinctly dangerous .

 

[MartinW148]

Wondering what others experiences of the stock 378ah battery is. And also comparisons with other systems.

Most of my riding is steep up and descents. Finding about 3000 feet of ascent total and 10-20 miles is about the limit. 2 hours riding and battery done.

Not unhappy with that, and realise the battery is 25% smaller than other bikes. But I then see reviews of Levos doing all day rides and 40 miles rides. Is that for real? Or only on very flat terrain?

I can get 40 miles out a flat ride on my Jam2. Most of that is still offroad terrain but low power modes needed only.

BTW I weigh about 70kg so there is a definite weight benefit I guess

 

[MartinW148]

After 6 months of riding gentle Suffolk rolling hills I easily get 35miles out of my Jam 2 ltd , I am 65kg and ride in eco and off where appropriate. With Trail and Boost as necessary.However do try to,keep off road where-ever possible (75%) Recently just got back to base in the Red with 34 miles on the clock...not bad on the small battery.
I find I want to ride further each outing so now need the expensive TEC pack
Be interesting to see what the cold snap will do to range as my Focus is kept,in unheated garage....STMBO would frown should I bring it inside ....well as long as she does not throw something its worth it!
Have fun. ..PS dont like riding this icy stuff with knobbly tyres! Feeld distinctly dangerous .

Will be interested to see how the battery fares.

Mine too lives in an unheated garage, but I have wrapped the frame in a blanket just in case.

 

[Gutch]

I weigh 200#. Have a Jam 29er Pro. I can do 25miles in ECO only with 3k ft elevation climb and the battery is toast.

 

[ricardowight]

I have a Jam 2 Ltd Plus.
I weigh 89kgs (14 stone in old money!).
I've managed 35 miles (56km) with 2558ft (780m) climbing out of a full charge.
That was split over a 17.7 mile night ride, after which the battery indicator was showing three bars of juice left, so I didn't bother charging up. Went for another ride the next day and did the other 17.3 miles. By the time I got home the indicator was red, so the battery was pretty much done I reckon!
The second ride had a bit more climbing than the first one.
I rode pretty much in Eco and Off, with only the odd burst of Trail mode for steep bits.
Used Boost for about 100 metres uphill, just to show my mate on a normal bike how crazy it is.
Needless to say he's got a Jam2 now too!!!!
I live on the Isle of Wight so there are plenty of hills (nothing too tech though). I'm really delighted with the Jam2, can't keep off it!
Happy days.

 

[steve_sordy]

The second half of my attempt to flatten the battery on my Focus Jam2.

The first half started with Range at 40miles in Eco, 30m in Trail and 20 in Boost and after 20 miles ended with figures of 22m in Eco, 16m in Trail, and 11m in Boost.

Today I went to Sherwood Pines trail centre. It has a relatively easy red, but the off-piste sections can be a bit more challenging. I determined to flatten the battery by going everywhere in Trail with the Boost as and when. I sought out every hill and set my route to do the longer ones several times. Warm for the time of year, about 9degC.

After about 9 miles, the Range fell to zero and shortly afterwards, the display switched to Eco but in red instead of blue. The pedal assist continued for another mile and then the motor switched off. The display continued, but in "off" mode. It would not switch back on. I switched over to the TEC pack battery and finished the ride. I still have to flatten that one.

The problem was that when I got home the charger would not charge the flat battery (separate thread in the Q&A section). I've got the LBS working on that. They did confirm that I had not done anything wrong by draining the battery until it switched itself off.

Summary:
The battery did better than I thought in the first 20 miles, but I was pedalling above the cut-off speed for some of that. But in the second part, I went through the forecast 16m Trail in 9m. I was using Boost now and then and I was seeking out hills and steep climbs (although they were short).

So far, I believe that the forecast ranges are pretty accurate. I like the way the display turns to red. The spare battery fits nicely into my Camelbak (the spare battery looks a bit of a wart when fitted) and although the pack feels heavy in my hand, I just don't notice the extra weight when it's on my back. The battery weighs 2.30 kg (5lbs), including the connecting cable and the rubber bump strips.

Apart from the battery charging problem, very happy so far.

 

[highpeakrider]

Why would you carry the spare battery in a camelback?
The bike provides a mount and cable storage, why would you risk back damage if you have an heavy fall?

 

[steve_sordy]

Why would you carry the spare battery in a camelback?
The bike provides a mount and cable storage, why would you risk back damage if you have an heavy fall?

I am aware of that, I just don't like the look of the bike with the spare battery on it. The battery is nice and flat and the bladder is between me and it, plus the padded frame of the backpack. To be honest although I have fallen onto my back pack many, many times, I have never ever hurt myself even though there is all sorts of hard stuff in there. But you are correct to sound a cautionary note, I have never carried anything quite so big and lumpy in my pack before. For sure, I won't be able to get my windproof in there if the weather warms up! I guess that it will be a passing phase!