Most efficient use of battery.

[Gubbins]

As I get older I find I am using more of the battery so am interested in finding the best way to go further. The best savings have to be on the hills, but how best to climb them.
I have found that at a constant speed with slow cadence if I change down a cog and maintain the same speed (which is easier to pedal) then surprisingly my hr goes up a goodly bit! As the bosch drive is amplifying my effort is it using more juice as am I? Am I better on full power and get up there quickly, or at lower power and take my time. It's hard to judge looking at the battery meter..

 

[Artstu]

My bike seems to have upped its game in tour mode, or my perception has changed. Certainly my rides in tour have seen the Bosch system giving me a lot of help on the hills, and I'm amazed to be able to tackle even the steepest hills. It certainly isn't easy to resist thumbing it into turbo though.
My bike gives the most power at a lower cadence than I like, not so easy on the knees.
Never using more than Tour has to be the way to go further, and dropping to Eco or off on the easy bits.

I am going to try a ride on Eco again, I have a feeling it will end up a failure though, being slower than an ordinary bike.

 

[Gubbins]

My bike seems to have upped its game in tour mode, or my perception has changed. Certainly my rides in tour have seen the Bosch system giving me a lot of help on the hills, and I'm amazed to be able to tackle even the steepest hills. It certainly isn't easy to resist thumbing it into turbo though.
My bike gives the most power at a lower cadence than I like, not so easy on the knees.
Never using more than Tour has to be the way to go further, and dropping to Eco or off on the easy bits.

I am going to try a ride on Eco again, I have a feeling it will end up a failure though, being slower than an ordinary bike.

Mine also seems to have more grunt in tour, but I thought it was just me!

 

[Deleted member 4366]

As I get older I find I am using more of the battery so am interested in finding the best way to go further. The best savings have to be on the hills, but how best to climb them.

That's a very good question. I'm going to describe principles; however, the Bosch system is quite complicated, so I'm not sure how the controller affects the torque, plus it's going to be different in the different modes, so let's talk amount the highest mode, where the principles most likely apply.

Crank motors are the same as hub-motors in that the slower they turn, the more torque they can make, which means that you can get more help by pedalling slowly.

There's another effect that means that when the motor slows down, the efficiency goes down with it once it goes below about half of it's maximum speed, so the slower it goes, the more battery it uses. For this reason, to get the most from the battery, you need to keep the crank rotating at a speed above half of its maximum, which i guess means above about 45 rpm.

Your pedalling will have a best efficiency at a certain RPM too, which is probably somewhere between 50 and 70 rpm. You can also get more torque by pedalling a bit slower, so to get up steep hills, you need to pedal a bit slower than normal and the motor needs to go slower than normal, but this wastes energy for both you and the motor.

It's not easy to pedal at 60 RPM up a steep hill, but if you can, that's the answer.

 

[Gubbins]

That's a very good question. I'm going to describe principles; however, the Bosch system is quite complicated, so I'm not sure how the controller affects the torque, plus it's going to be different in the different modes, so let's talk amount the highest mode, where the principles most likely apply.

Crank motors are the same as hub-motors in that the slower they turn, the more torque they can make, which means that you can get more help by pedalling slowly.

There's another effect that means that when the motor slows down, the efficiency goes down with it once it goes below about half of it's maximum speed, so the slower it goes, the more battery it uses. For this reason, to get the most from the battery, you need to keep the crank rotating at a speed above half of its maximum, which i guess means above about 45 rpm.

Your pedalling will have a best efficiency at a certain RPM too, which is probably somewhere between 50 and 70 rpm. You can also get more torque by pedalling a bit slower, so to get up steep hills, you need to pedal a bit slower than normal and the motor needs to go slower than normal, but this wastes energy for both you and the motor.

It's not easy to pedal at 60 RPM up a steep hill, but if you can, that's the answer.

Sounds logical.
Will give it a try nest time out.. The hill in question isnt steep, its just long and uses 2 of my battery segments, so will try it pedaling at over 60 rpms. I think I should fit a cadence sensor if this shows some improvement! Fortunately coming back down doesn't use any!!!
Cheers

 

[Gubbins]

So, tried an economy ride today.. Used eco mode whenever possible and tour on all but the steepest hills. 30 miles, 2800 ft and 2 bars left on the display, although it's probably only 1 and a bit! Did this by changing down a gear to keep the cranks spinning a bit faster and using first gear in tour on the hills (normally use turbo and go up as fast as possible). I don't need statins to make my legs ache!

 

[jackhandy]

It's not easy to pedal at 60 RPM up a steep hill, but if you can, that's the answer.

I find that most people returning to riding tend to try to blast up hills & half-kill themselves in the process.
I find D8veh's methodology is right for me - Settle-in to a comfortable, 60-70, cadence BEFORE the start of the uphill section & keep changing down to maintain that without straining, so that I'm three-parts of the way up before feeling the burn.

I've managed a few 25% hills like that, but have to restrain the urge to "get it over with".