Do E-bike riders get more exercise than regular cyclists ?

[stodd]

Last week, I decided not to charge my battery even though it was down to 20%. I wanted to see what the actual range was; the estimate on the control bears little relation to reality. I got 108 miles from the 400w battery, and the lights still worked even though the motor didn't. The upshot of this was that I climbed a hill with a bike weighing 25kg. Surely that's more exercise than I'd get with a normal bike!

I've never been brave enough to try that; even though we have the advantage that home is near the bottom of the (smallish) local hills, not near the top.

Oddly enough, it felt easier than the same hill on my 10kg Brompton. Perhaps the tyres?

or the gears?

[hemo]

Going low is ok for a range finder test but generally will start to stress the battery if done regularly, it is ok as an occassional get me home if you happen to end up on along ride. The real damage that can occur is when voltage sag comes in to play and cuts power, if you wait sag will rebound then you can carry on but it is a sign to stop stressing the cells. 40- 80% is the best range to keep the battery in when not in use.

[Phil Fouracre]

Just seen this reply - can I ask a couple of questions that have been interesting me as a keen ebiker! how long is defined as ‘not in use’ re batteries, and is there a practical/accurate way to check charge % level?

[hemo]

Just seen this reply - can I ask a couple of questions that have been interesting me as a keen ebiker! how long is defined as ‘not in use’ re batteries, and is there a practical/accurate way to check charge % level?

I tend to class as not in use more then a couple of days, a fully charged battery lessens the life span as it will cause cells to age early by loss of capacity. Left fully charged the ions interact and small nano particles are deposited on cell Anode/Cathodes, the deposits cause voltage flow to suffer and in turn cause cells to heat up (internal resistance). IR is a major cause of voltage sag .
In the short term damage is minimal but longer term 2- 3 weeks or months on end the aging will hasten.

A battery down on capacity will still be useable for several years but range is somewhat affected and voltage sag becomes more prevalent ( another sign of aging ), where as a battery looked after a bit more carefully will keep it's capacity and voltage drop will be more linear. Voltage sag is a sign of higher internal resistance though all battery's suffer sag as this is normal when a load is applied, an aged battery with higher IR will suffer more so and will cut out if too high a load is asked of it. When a higher load is applied voltage will readily collapse then bounce back as if all is ok.

Ideally charging to only 4.1v would be better as the top 10% of the voltage holds very little mah/capacity and is often depleted very quickly with in the first couple km's of use. However all generically used BMS are set for 4.2v for balance charging, trying to only charge to 4.1v or less with one fitted cause more issues then it solves so it's not worth the bother. Instead it is better to manage the battery charging so that you only charge approx. 6 - 12hrs before use.
If I go out on a long ride on return I only charge partly if the voltage is below 3.6v per cell/group and stop the charge at between 3.75 - 3.85v, I then leave the battery and fully charge up several hours before I need it again.

You can buy for £'s a simple battery voltage gauge that will give three readings, a battery segment bar, voltage readout and a % readout. A battery's bms has bottom end voltage cut off (known as LVC), this is normally 3.2v (0 -10%) per cell /group. The top end we know is 4.2v (100%) per cell/group, although not 100% linear you can allow 10% for each 0.1v decrease.
https://www.ebay.co.uk/itm/12V-24V-36V- ... 516d1dccb4
Half the price on Aliexpress, I always add one to my batteries that I build.

[Grandad]

My understanding of this explanation is that after a ride it's better to leave recharging the battery until immediately before the next ride. This assumes that it has not completely discharged on the ride.

Is this correct?

[hemo]

My understanding of this explanation is that after a ride it's better to leave recharging the battery until immediately before the next ride. This assumes that it has not completely discharged on the ride.

Is this correct?

Yes.

[hemo]

If leaving a battery for some time often over winter as some don't venture out much then leave the battery at approx. 38v a storage charge. Once a month check the voltage to make sure it hasn't drained any voltage.

The issue with lithium batteries is no one who sells them actually know how to look after them (well not many) , they just tell you to charge them up. It is good business to tell people to keep them charged all the time because they will be back for another one when it[s knackered. With the price of batteries it's an expense you don't need to fork out for every 2 or 3 years, there are probably hundreds of ebikes abandoned in sheds/garages because the batteries are knackered. Stories are told now of then of some one who has an ebike and then for some reason wasn't able to ride it for months and months or even a year or so and wonder why the bike doesn't work. Lithium likes to be used left to idly stand they deteriorate due to aging.

I have a pair of 5 yo 522wh/14.5ah batteries and both still give me up to 35 miles range which is about 65 - 70% of their original capacity, in the early years of owning them I abused them a bit with too much current and the cells suffered.

[horizon]

there are probably hundreds of ebikes abandoned in sheds/garages because the batteries are knackered.

Hmm. I think this was sort of predicted as consequence of the novelty aspect of e-bikes. People often say to me how much they would like an e-bike and I know they would have no intention whatsoever of cycling anywhere (which doesn't negate the usefulness of e-bikes to those who do actually ride them).

However, what it might also mean is that there are a lot of bargains to be had for the price of a new battery, assuming that technology hasn't left the other parts too far behind. Am I right?

[Cyril Haearn]

Yes but people hoard stuff, many do not bother selling, when they die in a few decades and the garages are cleared the ebikes shall not be much use