bartel.michiels

I've a new bike with the Shimano Steps system.

The first time I charged the battery 100 % and while riding it discharges gradually percent per percent till it was 0 % after 66 km. That was normal.

The next times I also charged it 100 % and it discharges gradually while riding to 23 %, then it dropped in a second to 4 %, The range was indicating 22 km (at 23 %) and within a second the range indicated 2 km. From the second time I charged the battery this was happening all the times.

I thought it could be a faulty battery so I brought it to a Shimano service center. A few days later they returned me a new battery (without explanation) and I thought the problem was solved. Not.

Today I rode the first time with te new battery and encountered the same problem.

Can there be another reason than the battery for this problem?

( I will return to the Shimano service center of course).


Thx

Bart

drowling23

If it's not the battery, it could be the controller misbehaving.

1nterceptor

From Shimano's manuals; may or may not be your issue:

• If the battery has become completely empty, charge it as
soon as possible. If the battery is left uncharged, it may
cause the battery to deteriorate and become unusable.

• If the battery has been charged in a low temperature
environment (5 °C or below), the maximum riding distance
per full charge becomes shorter. This is due to a
characteristic of the battery. If the battery is charged at
room temperature, the maximum riding distance becomes
normal again.

unterhausen

66km seems a long way on one charge. Lithium batteries are happiest in a fairly narrow range of voltages. Once they get lower than that range, they suffer damage. But also, once they are depleted, the voltage drops precipitously from near normal to unusable. It really depends on the way that shimano has implemented the state of charge indication. Could be they are not trying to estimate the amount of usable charge left, just showing the voltage. It may just be that you need to get used to what the indicator is showing you

Bikewolf

Although you may drain your battery 100% my advice is to avoid that. Charge when you are left with only one marker on the display (about 20%).

Casimere

I know this is an old post, but I’ve just had my identical problem fixed.
Everything ok down to 21%, then sudden jump to 8%, every time. New battery supplied under warranty, but still same problem.
Took bike to shimano service shop where two software updates were needed - one for main computer and other for motor management - problem has now disappeared and power meter works normally!