Shimano battery issues with EP8 motor

[leftside]

I've already posted this on the Commencal Meta SX Power thread, but wondered if other bikes with the Shimano EP8 motor and battery have seen a similar problem. Basically, the battery level drops from around 30% to 2% extremely quickly.

I also have a YT Decoy with Shimano E8000 motor.

These are real examples that happen all the time on my local mountain.

Decoy with E8000. Garmin shows 30% battery left, 900 meters elevation completed, 20km distance completed and the Garmin estimates I have 10km distance remaining. 2 bars left on the Shimano display. Battery drains consistently from here (i.e. Garmin shows 30%, 29%, 28%, etc) and I end up riding 28km, 1100m elevation and only a few % left on the battery being shown on the Garmin. Shimano display at 1 bar.

Meta Power with EP8. Garmin shows 30% battery left, 900 meters elevation completed, 20km distance completed and the Garmin estimates I have 10km distance remaining (it actually estimates slightly higher as I have a bigger battery in the Meta, but these figures are close enough). 2 bars left on the Shimano display. Battery drains very quickly from here and I end up riding 21km, 950m elevation. Garmin display shows the battery go straight from 30% to 2%. Shimano display goes very quickly from 2 bars to flashing red.

I have all the latest Shimano firmware from using the E-Tube app. I also have the latest software running on the Garmin 1030 Plus. I also have the Shimano SM-PCE02, but Shimano now use smaller ports on the display. So I also needed to order an adapter. Hopefully that adapter will arrive soon and I can plug the bike into the SM-PCE02 and see what is going on.

Commencal have said I can borrow another battery the next time I'm in Squamish (where their outlet store is) and see if the same problem happens. There are a few of us with the Meta/EP8 who are having this problem.

If I didn't already have a Decoy, and didn't have the Garmin connected to the battery I might not have noticed this issue so much. I might simply have scratched my head at the problem rather than going "WTF?!"

 

[Mteam]

The decoy doesn't use a shimano battery does it? Whereas the commencal does use shimano battery. Might just be completely normal behaviour for the shimano battery.

 

[leftside]

The decoy doesn't use a shimano battery does it? Whereas the commencal does use shimano battery. Might just be completely normal behaviour for the shimano battery.

Yes the Decoy uses a customized Shimano battery. I'm not sure it would be normal behavior that the older E8000 motor/540W battery is getting around 20% more range than the newer EP8 motor/630W battery?

 

[Steve38]

Similar behavoir with the EP8 / E8036 Battery combo in my Merida e160
Once you get down to 1 bar / 20% supposedly left if does drop off the cliff very quickly
I just now try to factor this into my rides, but still have been caught short a few times

 

[RustyIron]

Same behavior on my Heckler. Once I'm down to one bar, I'd better be close to the truck.

 

[leftside]

I could live with the behavior of losing the last 20% quickly if the battery from 5 to 1 bars (100% - 20%) was giving me more range overall with the Shimano 630W battery vs the Shimano 540W battery.

It appears some of us are "losing" the last 20% - 30% of range with the EP8/630W combo. The older E8000/540W combo doesn’t exhibit this behaviour and is giving me more range overall.

According to my Garmin, if the EP8/630W stayed consistent I would get about 10% more range than the E8000/540W combo, which is what I would have expected, but then along comes the sudden drop…

I’ll report back when I attach the SM-PCE02 or when I go to Squamish and try a different battery.

 

[lightning]

This is almost certainly a faulty battery, it's the same as when my iphone battery was at the end of its life, it would get to around 20% then suddenly die.

The Shimano battery is poor. Mine is showing 79% "battery health" after only 60 charge cycles and l am about to send it back to the dealer under warranty.

 

[Dan63]

Is the aux power/light function enabled? This can cause this behaviour. You can check/switch it off with stunlocker.

 

[leftside]

Is the aux power/light function enabled? This can cause this behaviour. You can check/switch it off with stunlocker.

I hear what you are saying. The Decoy would shutdown when the battery was at around 10% to preserve some capacity for a light (some sort of regulation?), but I hooked up the SM-PCE02 to turn that setting off and now the Decoy stops at around 4%. I can watch the Decoy battery go down in 1% increments all the way to 4% with the Garmin.

But, unfortunately this doesn't explain the Meta behavior. The Garmin will display anywhere between 20% - 30% before immediately dropping to 2% whether power/light function is enabled or not. I agree with @lightning that it is a faulty battery, as this is the typical behavior of faulty batteries in other devices.

 

[maynard]

It's like the fuel gauge in your car . The first half a tank gets better mileage than the second .

 

[leftside]

It's like the fuel gauge in your car . The first half a tank gets better mileage than the second .

Does your fuel gauge go from being 2/3rds down and then drop immediately into the red?

Imagine being on the motorway/highway and your fuel gauge is telling you there is 1/3 tank left. You look 1 second later and your fuel gauge is in the red and the gas/petrol light comes on.

 

[lightning]

lt means one or more of the cells in the battery has either failed or deteriorated.

The cells are arranged in sets, if the battery management circuit detects one set with a low voltage it will either shut down the battery or reduce the range to around 2%

What happens with mine is, once it is down to 20% if you use "Turbo" the battery will sometimes shut down.

Of course then it won't turn back on, meaning a slow ride home.

l can't return the battery at the moment because the dealer says there are no replacements available, and l don't want to be without the bike for weeks or months while one comes into stock.

 

[Juho]

I think I have this same issue with my 2021 Meta Power 27. EP8 + 630Wh battery. Battery bars are dropping from 2 to red very fast. I am interested to see how this sorts out. Wondering is my battery faulty or is this "normal".

 

[Mteam]

I have a couple of friend with ep8 + shimano 630wh batteries and they havent reported seeing this behaviour, so maybe it is simply a faulty battery .

 

[leftside]

lt means one or more of the cells in the battery has either failed or deteriorated.

The cells are arranged in sets, if the battery management circuit detects one set with a low voltage it will either shut down the battery or reduce the range to around 2%

What happens with mine is, once it is down to 20% if you use "Turbo" the battery will sometimes shut down.

Of course then it won't turn back on, meaning a slow ride home.

l can't return the battery at the moment because the dealer says there are no replacements available, and l don't want to be without the bike for weeks or months while one comes into stock.

That makes total sense. I’ve also noticed it being worse if I have the bike in turbo/boost for a “final quick lap”.

Same deal here as well with no other batteries available for warranty replacement (or purchase). I was told hopefully in the Spring.

 

[Flemming]

On my commencal meta power (EP8 630w) the first 20% (from 100% to 80%) last much much longer than the last 20% from (20% to power cut) and I believe it is down to a stupid battery indicator in the software. I would guess that the first 30% gives as much range as the last 70%.

And why do we only have the shitty 5 bar battery indicator??

I have also experienced that with one bar left, the bike switches to forced eco mode when asked to put down some power, even though I was sure that there was more range left. I would guess that power draw causes the voltage to drop below the minimum charge and the software says "that's it" even though the voltage returns to above the minimum once the power is less or totally gone, but once it has entered forced eco mode there is no going back.

I have read some where that some Li-ion charges do the balancering at the end of the charging process, which I believe is the way Shimano do it. During charging I have unplugged the charge and check both the battery and the bike and both claims 5 bars, but the charger continues for 1 to 2 hours. My guess is that it does that balancing here.

If the battery is not properly balanced you will not get full range, before some of the cells are below the minimum charge and the bike shuts down.

 

[lightning]

Yes l also noticed that the charger continues for an hour or so at the end of the process, and during that time it is nowhere near as hot as during the main charge cycle.

Maybe that's what it's doing.

 

[leftside]

I just want to clarify that their are two behaviors at play here. One is "expected behavior" the other is probably indicative of a problem with the battery.

1) The battery will run down fairly consistently to 1 bar on the bike display/20% on something like a Garmin. The bike/battery will continue running until the battery hits around 10% and then it will stop. This is expected behavior as the battery preserves some juice to meet regulations for a light being attached. But, as very few of us attach a light to the battery, this light setting can be disabled with something like STUnlocker or the SM-PCE02 . I used the SM-PCE02 and now my Decoy battery will go down to 5% before stopping.

2) The battery will run down fairly consistently to 1-2 bars on the bike display/20% - 40% displayed on something like a Garmin. The bike/battery will suddenly stop. Bike display will flash red. Garmin will display 2%. This is unexpected behavior and we are losing a lot of range.

 

[lightning]

That's true, mine came with the lights turned off on the software, my battery when l got it would run down steadily to around 2% before it shut off.

(l've got home with the bike still running and checked the remaining battery reserve on Stunlocker, it's been under 5%)

When it got to 1 bar on the display l could get around 6 more miles.

Now, once it's on 1 bar l've no idea how far l will get, but it's certainly not 6 miles.

That's after 60 charge cycles. Stunlocker says my battery "health" is at 79%

 

[Cyclopath1000]

2018 meta power e8000 motor with 504 batteries.
Batt #1 started doing that after about 1.5 years. About 1500 miles of use. 20% to red and off in a mile or two. Bought a second batt ( not integrated. ) That one is not yet doing that.
Now the connector to the battery mount on batt #1 has cracked at the negative terminal and they don't stock spare parts at Shimano USA and they initially told me it's out of warrenty but now they might be hedging because I've threatened to make it public that Shimano isn't considering that there ARE DURABLE PRODUCTS. A DURABLE PRODUCT LASTS AT LEAST 7 YEARS. I actually asked Shimano USA for Shimano Japan's CEO name and address so I can directly communicate with the main office that Shimano USA is a marketing setup that doesn't have the authority or the expertise to maintain their products and the end game will they will ruin Shimano's name in USA seeing they have staked their future on such advanced technology.
Batt number 3 is being shipped from Europe being bought from a European source on MY dime ( $616).
We need to hold their feet to the fire. Either contract with a batt refurbishment company, or set up their own asap.

There are now 5 or more competitors and why exactly would I either recommend ep8 for others or get a second bike with ep8 when their non existent customer service by people here at Shimano USA let all these issues fester. Shimano Japan needs to hear from us .

Shimano USA is destroying a great companies reputation. They need to receive assistance, parts and replacements asap actually ahead of their supply to bike companies.

I'm pissed. And I promised Shimano USA that I will get all this to the executive suite.

What a sorry excuse for a great industrial company's USA arm.

 

[1oldfart]

I am not an expert but here are my 2 explanations.
Showing very little battery use to a short tester is great marketing.
All the 5 bars are not 20% each.
We cannot empty a battery it would limit the longevity.
Maybe the battery showing empty, the assist stops when 5% is still left in the *tank*.
I just use my watch i know i can ride 4Hrs no problem.
Those lights and numbers are just kids toys, not real.

 

[Cyclopath1000]

@1oldfart: I disagree. Typically one of the packs.of ten 3.something volt batteries in one of 4 stacks of ten isn't holding equivalent voltage as it's soul mates and it triggers that 1/5 of the total battery to be somehow either partially or totally unavailable. The result is now the batt is at best 80% of when all the cells were able to stay within.the specified voltage. A qualified battery service can read each cell ( I think they deconstruct the stacks ) and replace the ones that fail to equilibrate by voltage. Before covid 19 the city of industry rebuilder was quoting several hundred for a.complete redo.

Notice where Shimano went for batteries !! China. That's not their usual place place they farm out production.

Consider that the supplier is basically using poor quality components so as to sandbag a foreign power in their quest for total dominance in ev technology .

 

[Cyclopath1000]

Five stacks of ten not 4.

 

[1oldfart]

Well i read a rider had 2 Shimano Ebikes and 2 Giant Ebikes and from his experience
Shimano was of less quality. I also read a few complaints about early degradation
of Shimano battery. To me it is clear Shimano is using the name marketing the name
and profiting with low quality products. I never bought 1 i do not trust them.