I have a E8010 battery that from one day to the other wont charge anymore. I am using the original Shimano charger. It's currently showing two bars, so it's not completely empty and I can use it in my bike. What's the problem? @Greg Watts
Welcome to the forum,
@noemo! Annoying one this - and unfortunately not uncommon with Shimano STEPS batteries. A few things to check, roughly in order of likelihood:
1. The charger port / connection Give the charging port on the battery a good look - dirt, corrosion or a bent pin will stop it dead. Same for the charger plug itself. Even a tiny bit of crud can break the circuit.
2. The charger LED behaviour What is the charger light doing when you plug it in? Solid, blinking, nothing? That tells you a lot. We've had similar reports on the forum -
@steve_sordy's post describes an EC-E8004 charger that just sat there blinking once every two seconds with no charge going in. In that case it turned out to be the charger rather than the battery.
3. The battery's own protection circuit Shimano batteries have a BMS (battery management system) that can put the battery into a protection state - sometimes triggered by a cell imbalance, temperature, or a previous deep discharge. The fact that you have two bars and can still ride is a reasonable sign, but it doesn't rule out the BMS refusing to accept charge.
4. Try a known-good charger if you can If you know anyone local with the same Shimano charger, swap and test. Narrows it down quickly to charger vs battery.
If none of that sorts it, it's worth taking it to a Shimano-authorised dealer - they can run a proper diagnostic through E-Tube Project and read any fault codes the battery is logging.
