Lost 25% battery very quickly.

[outerlimits]

Done a group ride of 25km and 500m elevation yesterday. Had 50% left when my mate asked toward the end of the ride.
Rode up a 200m long climb in turbo, then bombed down about 1km back to the car. It then said I had just 25% left.
Realy find it hard to believe I chewed through 25% battery in just 1.2km with only a small climb and the rest down hill.
I did crash coming down, nothing major.
Any ideas as to why it said I used 25% power so quickly ?

 

[Rob Rides EMTB]

Hmm that is strange. I know that Turbo does rinse the battery quickly but you said it was just a short amount that you used.

 

[outerlimits]

After another ride today after recharging, all seems normal.

 

[knut7]

Is it getting cold in Australia yet?? Here's one possible explaination. If you start off with a indoor-temperature battery and ride in low temperatures, the battery's ability to deliver high currents is reduced. Also, as the state of charge (SOC) is falling, the battery needs to deliver more amps to maintain the power output. A battery with 90% SOC will need to deliver 12,2A to produce 500W. A battery with 40% SOC will need to deliver 13,9A. If the battery is cold enough, it may struggle to deliver the power needed. What happens then is a massive drop of battery voltage, and the battery soon empties. When riding in cold conditions you should try to avoid using the high assistance levels when you're down to like 2/5 bars of battery. Depending on how much more you plan to ride.

 

[outerlimits]

Is it getting cold in Australia yet?? Here's one possible explaination. If you start off with a indoor-temperature battery and ride in low temperatures, the battery's ability to deliver high currents is reduced. Also, as the state of charge (SOC) is falling, the battery needs to deliver more amps to maintain the power output. A battery with 90% SOC will need to deliver 12,2A to produce 500W. A battery with 40% SOC will need to deliver 13,9A. If the battery is cold enough, it may struggle to deliver the power needed. What happens then is a massive drop of battery voltage, and the battery soon empties. When riding in cold conditions you should try to avoid using the high assistance levels when you're down to like 2/5 bars of battery. Depending on how much more you plan to ride.

Yeah it’s cooling down here a little bit @ 29deg C or 84F. Should be good for 18-25c right through winter.

 

[knut7]

18-25*C sounds like very good conditions for the battery. It could still be that the battery was forced to deliver more power than it was able to in that situation. This is more common in temperatures of 10*C and less, as the temperature ads limitation to the battery. I guess battery overload could still be an explaination to what you experienced. If rode uphill on max assistance with a low cadence, and a backpack full of beers.

It could be you reached the limit of the system, or there could be something wrong with the battery. I would just keep riding and see if it happens again.