Extending Battery Life

[High Plains Rider]

I am preparing for a couple of bike ride events both have days which will include 50 mile treks. My Rad Rover battery should last for approximately 30 miles. However, today I went 25 miles and stayed mostly on PA 1 and 2. My first bar went away after 21 miles. Does this mean I could potentially go 80 miles if I stay on PA 1 and 2. Does anyone have any experience in extending battery life?

 

[JRA]

Calculating the amount of wh/mi you can use to achieve your 50 mile goal is easy. Take the wh's of your battery and divide it by the distance desired. How you get to that figure is up to you but in general the more you pedal and using a lesser assist level will yield the greatest mileage.

One thing to keep in mind that many don't factor in is that a fully charged battery at full voltage will have the best possible power and thus the ability to go the furthest per wh. But as you proceed the voltage will sag and there will be less power so in effect you are constantly going towards lesser mileage capability as the battery wears down. In other words if you can now go 21 miles and lose only one bar you can't say that all the bars will yield 21 miles.

 

[DDBB]

Don't forget to factor in headwinds.

 

[Mr. Coffee]

Hyper-mailing tips:

• Go slow. Peak efficiency is going to be achieved at speeds under 15mph. Above that speed a lot of the watt-hours you consume will be used to push air. Much depends on the bike but usually the sweet spot is 12-15mph.
• Ride with as high a tire pressure as you can get away with.
• If you are riding on pavement use smooth tires or at least a hybrid tire.
• Ride on the very best pavement you can find. Gravel or chip-seal or even old concrete will produce a higher rolling resistance and thus fewer miles on a charge.

What I'd say is that with a hub drive and a ~700wh battery 50 miles is very possible as long as the ride is flat or in very gentle terrain. Significant elevation changes can easily cut your range in half.

 

[DDBB]

Going slow is huge.

 

[Berserker26]

Hyper-mailing tips:

• Ride with as high a tire pressure as you can get away with..

This bodes true if you're on perfectly paved roads. If you are on anything else with crappy pavement etc.. then lower the pressure a bit. The higher pressure can sap momentum if you are constantly hitting little bumps. If you lower the pressure it'll just eat up those bumps. Not to mention a far comfy ride.

 

[rich c]

More hyper miling techniques;
Accelerate slowly
Find the optimum cadence for your highest motor efficiency
Shift a lot to stay at efficient cadence
Anticipate slowdowns and coast as much as possible

 

[6zfshdb]

Some are better than others but most battery bar gauges are not linear. Each bar represents a progressively smaller number of watt hours.

The only way to know what the gauge is actually telling you is to do a test. Find a place where you can ride in a consistent manner and note your mileage as each bar disappears. This will give you a rough idea of what each bar represents. Of course this will vary as you change PAS levels or use a throttle if your bike is so equipped.

 

[PaD]

Many good tips in the answers above.
I can confirm that speed is really a big part of it. I get very good range from the 600Wh battery on my Vado and I’m sure the main reason is it’s a EU bike with power cut off at 15.5mph ( well actually a little bit higher after corrected wheel circumference) and staying in Eco mode most of the time. ( There are 3 support levels on a Vado. Eco, Sport and Turbo)
I choose a 40tooth crankwheel instead of the standard 48 for the Vado 5.0 as I think it’s better for EU speed limit and my preference for a little higher cadence.
I’m not really sure what cadence is the most efficient for the Brose motor but using the gears and keeping the pedals spinning in Eco mode feels good. But I do occasionally use Sport mode for inclines or if the headwind is strong.
Anticipate slowdowns is a great tip from @rich c . Facing a strong headwind I would definitely accept a lower speed to make the battery last all the way to the day’s destination. I usually let speed go down on inclines but It is fun to go into Sport or Turbo and sprint up a hill

 

[ilanarama]

What about gearing? I usually use my higher assist levels only for going up hills, and I've wondered, is it better (for battery life) to use a lower gear, which makes the battery work less but for a longer time as it's slower going, or a higher gear, which gets me to the top of the hill (and back into a lower assist level) more quickly, but presumably makes the battery work harder? Or does it all come out in the wash?

 

[nublar]

I went from 15 watt-hr/mile to 12 watt-hr/mile @ 20 mph by using the add-on drop bars

 

[Mr. Coffee]

This bodes true if you're on perfectly paved roads. If you are on anything else with crappy pavement etc.. then lower the pressure a bit. The higher pressure can sap momentum if you are constantly hitting little bumps. If you lower the pressure it'll just eat up those bumps. Not to mention a far comfy ride.

True, but if you are riding on a poor surface you won't be hyper-miling that day.

With 1000wh of batteries I can easily cover 70 miles in a day on reasonably good pavement with modest elevation gain. With the same terrain on gravel or dirt roads I would be extremely lucky to make much more than 50 miles.

 

[TAZMANIMAN]

We generally get the most out of our first bar and then average about 8 miles or so a bar after. Our record was 54 miles on Erie Canal trail so, some paved some not but mostly level.
Something we really like on our display is that it has 5 bars of motor usage, the less it lights up the more you are doing, as well so it becomes a challenge to use less motor power especially when you can directly see the results!

 

[TAZMANIMAN]

I should add our batteries are 48v 10.4 ah

 

[MarkF]

Which bike and display do you have Taz? I like the idea of motor usage and the challenge to use less.

 

[DDBB]

My Yamaha display also has the power meter showing how much the motor is working in five or six bars, I forget which. I get great range if I keep it to two bars of power out showing and try not to go above that

 

[TAZMANIMAN]

We have 2 Xtreme Sedona models. We have been super pleased and even bought second batteries this year. Now our possibilities are broadening. We can go farther than our butts can handle now!

Which bike and display do you have Taz? I like the idea of motor usage and the challenge to use less.

 

[DDBB]

We also thought we'd want/need extra batteries but have decided 50mi. rides (if that) is about all our butts can handle. Unless we want to do overnight camping trips with the bikes we don't need more range.

 

[AHicks]

What about gearing? I usually use my higher assist levels only for going up hills, and I've wondered, is it better (for battery life) to use a lower gear, which makes the battery work less but for a longer time as it's slower going, or a higher gear, which gets me to the top of the hill (and back into a lower assist level) more quickly, but presumably makes the battery work harder? Or does it all come out in the wash?

My vote-
I'm assuming we're talking mid drive here? The lower/slower gear will be pulling less wattage of course, but you'll also have less wind resistance. So without other data, my vote for least amount of power used to climb the hill would be the one running at lower speed/wind resistance.

 

[GregGritton]

My vote-
I'm assuming we're talking mid drive here? The lower/slower gear will be pulling less wattage of course, but you'll also have less wind resistance. So without other data, my vote for least amount of power used to climb the hill would be the one running at lower speed/wind resistance.

If you are talking about a hub motor you probably want the opposite. Hub motors are inefficient at low speeds. Thus, I would bump the PAS level up and try to take the hill at a similar speed to the rest of the ride.

Even with a mid-drive, due to the squared nature of wind resistance, you would probably gaine range slowing your overall speed slightly (i.e. using a lower assistance level in the non-hill portion) than you would slowing the hill signicantly.