Bike usage and battery range

[UrbanPuma]

Bike usage and battery range - advice needed

Hi all

I have recently purchased a powacycle puma electric folding bike and would like some advice on preserving the battery range.

In pedelec mode, is there a difference in the amount of work the motor is doing depending on the gear i am riding in? For example, is there more power drawn from the motor in 2nd gear and less power drawn in 5th gear?

In throttle only mode, does using full throttle drain the battery more than at half throttle?

All advice would be much appreciated as i love my bike and want to enjoy it for many years to come.

Thanks

UrbanPuma

 

[flecc]

I have answered your question on the other thread where you entered it first. However, not to worry, here it is copied and pasted across:

The rule on these hub motors is that efficiency rises with revs and on hub motors is independent of whatever gear you are using.

Basically that means you should try to use the upper range of cruising speeds as the motor is most economical then. It's most wasteful at up to 8 mph when hill climbing for example, the wastage then falling as the speed increases.

Therefore the part your gears play in this is that you should use the gear that gives you the best advantage for helping the motor and bike up to speed. Generally speaking, higher cadences, that's the rotation speed of your pedalling, are best for rider efficiency, but use what you feel comfortable with to give the best contribution.

Full throttle drains more, so once up to speed, back it off enough to maintain the speed but give a saving.
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[UrbanPuma]

Thanks for replying flecc,

I'm new to the site and wasnt quite sure how it worked. Your advice is very helpful.

ps.i think this is a great site for people who own electric bikes - very informative.

Kind regards.

UrbanPuma

 

[flecc]

Thanks UrbanPuma, a pleasure to help.

You have the advantage on your bike of Powacycle's very moderate replacement battery price, but there are other things you can do to get the best battery life.

Lithium Ion batteries are best charged at every opportunity, and not run to flat each time. Running them to cut out is likely to give the shortest life. It's also best to avoid hot storage, like leaving the bike parked in direct sunlight for very long periods, as the batteries last best at moderate or low temperatures.

If you ever experience overload cutout on a hill, needing switching off and on to get it going again, it's best in future on climbs like that one to assist by pedalling a bit harder, backing off the twistgrip throttle at the same time to reduce the load on the battery a bit.

 

[UrbanPuma]

Hi again Flecc

My first experience on a hill using the throttle cut out but that was because my battery was very low. However, since charging the battery i have tackled hills in pedelec mode only with no problems.

Should i condition the battery a couple of times by letting the battery run very low before recharging after each use? My reason for this is that i would like to see how much range i can get out of a full charge.

UrbanPuma

 

[Ian]

UrbanPuma, does your Puma have a lithium-polymer (LiPo) or a nickel-metal-hydride (NiMh) battery. The reason for asking is that most Powacycle models are available with either but the optimum treatment differs between the types.

The Puma with LiPo battery is called the Puma LPX and seems to be the only one currently available.

 

[flecc]

Yes, it should have the first two or three as full discharges and charges for conditioning UrbanPuma, but then as I advised. That cutout when the battery is low isn't the problem I referred to. It's only cut out on a battery with a charge due to overload that should be avoided, and clearly yours is ok.

I think the Puma has been LPX only for some while now Ian, but I can't say if any old stock has been around.
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[UrbanPuma]

Hi Ian

I was told my battery was the LPX version, however on the back of the charger it says Lithium Ion. Does the charger need to read Lithium Polymer?

 

[flecc]

Lithium polymer batteries are also Lithium Ion, Urban Puma. The Polymer just refers to a different way of making a Li-ion battery, so your charger is fine.
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[UrbanPuma]

Ok. Thanks for the clarification flecc

Have a good day

 

[KidBriar]

Hi,

I've been reading with interest about the Polymer battery and its charging capacity. I am have a new Salisbury LPX delivered on Friday and am grateful to flecc and Ian for the advice.

I was wondering, after the first few times of fully discharging and then charging, would it harm the battery if it was 'topped up' say after 4 or 5 times? Also, would it cause harm to the battery if it was left on over the suggested charging time, for example if charging over night?

I can't wait until Friday, but any advice in the meantime would be great!

 

[flecc]

No harm will be done by recharging after any use, however small, and as explained, that's always best. However, once recharged that's it, there's no need to top up if it's been standing unused for a while since Li-ion types don't lose charge while standing, even after a year.

Although it's best to disconnect when charge is complete, that's mainly for general electrical safety reasons. Once fully charged, the battery's internal electronics will prevent any further charge. So if you need to leave it a few hours, that's ok as far as the battery is concerned.

The internal electronics in these batteries are extensive and complex. If you use the link I'm giving below, you can see photographs of the innards of a typical one, in this case the eZee 36 volt Li-ion Manganese:

Li-ion
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[KidBriar]

Thanks flecc, as ever your replies are very informative. Being a complete e bike novice, however, I assume your reply means, for example, if my battery is half charged after only 3 or 4 commutes to work, the battery would not be damaged if I put it on to fully recharge if it had half or more/less to go before being fully charged again provided I had fully discharged and charged 2 or 3 times previously?

I'm sorry if everyone thinks the answer is obvious, I really don't mean to be obtuse, but it is new to me!

 

[flecc]

I'm not entirely sure I understand, but once you've done the initial two to four full discharges and charges, just charging after every use is the way to go.

For example. I go to the supermarket and back, 3.6 miles and charge.

Subsequently I go to the DIY and back, 5.7 miles and charge.

Then a trip into Croydon and back, 9 miles and charge.

Then a trip to a local shop and back, 1.3 miles and charge.

You can see what I'm doing, a charge every time I use it, all the way to full charge cut out every time.

What I wouldn't do is use all 19.6 miles and then charge, for that shortens a lithium battery's life. I also wouldn't do any two or three of those trips before charging, because even that shortens the life more than necessary.

The rule is charge at every opportunity. My charger is plugged in and standing by the bike's parking spot all the time.
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[KidBriar]

Thanks flecc, yes I see now. Once the battery has had 2-4 full dishcarges, the rule of thumb is charge after every use even if the battery hasn't run out. I suppose I was thinking along the lines of a cell phone battery where it damages it to keep topping up!

Once I've used my Salisbury for a few different journeys (ie short commutes to work and a ride out at the weekend) I'll post a review.

Once again, thanks for all your help and advice.

 

[flecc]

A pleasure KidBriar.

A review would be very welcome as we haven't got one on the Salisbury at the moment, and new members looking for a bike to buy do value these.
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[UrbanPuma]

Battery range problem

Hi Flecc,

Hope you can help. Since purchasing my bike, i managed a range of 16 miles before it cut out on the hill (dead battery i assumed at the time). I fully charged it and have topped it up a couple of times since then, after doing approximately 5 miles each time.

Yesterday i had a full battery and cycled 16 miles. I was using pedelec mode mostly, only using the throttle to pull away and for short distances at a time. time. I also kept the bike in 2nd gear all the time. On the battery indicator all 4 lights were showing green so i assumed the battery had loads of juice left.

However, as i was cycling up the hill on queenstown road in battersea, the LED indicator lights started to flicker, then it went to 2 green lights and then it cut out and I had to push the bike from there.

My question is....is this normal? The powacycle website states LPX battery should give a range of 26-33 miles.

Does using the bike in 2nd gear - drain the battery more?
Is there anything i can do to get the optimum range or is there a problem with the battery?

Any advice is much appreciated

Thanks

UrbanPuma

 

[flecc]

It's best to use the highest speed you can cycle at, and the rider gear chosen makes no difference. At 8 mph or less, the consumption is highest, at 15 mph it's lowest.

When climbing under load, a sustained climb at around 8 mph or less can lead to a Li-ion battery like your LPX suffering chemical exhaustion, even though the lights look ok. If you get another cutout like that, switch off and pause a moment. Then switch back on and you should find the power returns. Then set off using less throttle and putting in more pedal effort to avoid the cutout repeating immediately. Resting the battery for a longer period allows more recovery.

To avoid cut out in the first place, in addition to keeping up the speed well clear of 8 mph, try using a lower throttle setting all the time. You'll usually find there's almost the same power at a much lower setting, while using less current from the battery.

The other thing that can cause cut-out is poor battery connections, so make sure those are gripping well and clean. Use a solvent to clean the metal faces if necessary to ensure a good current flow.

I wouldn't take too much notice of suppliers ranges, though Powacycle are better than most. Generally they promise the earth but rarely deliver much more then half the claims. Small wheel bikes like yours usually are in the 15 to 22 mile region, but much depends on the rider contribution and hills climbed of course.
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[UrbanPuma]

Hi Flecc,

My cycle computer said i was averaging at 6mph so if i average at 10mph in future, i should get a longer range?

 

[flecc]

Yes definitely, that 6 mph was a very low average, and consumption would be very high at that. Are you sure the computer is properly set for the wheel diameter, since that's an unusually low figure?

Keeping to 10 mph or more will give you a much better range and probably also eliminate cut-out problems.
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