Response to Flecc's advice on hill cut out

[musicbooks]

The only thing I have any question with is the li-ion battery on any bike. These do not like sustained high loadings, and you have some wicked hills in the Bath area, both long and steep. The Forte throttle will have to be used judiciously, avoiding long periods on steep hills at full throttle, while making an adequate contribution through the pedals. The temptation to relax on pedalling and wind the throttle fully open for long periods is likely to cause the battery safety cut-out to operate, leaving you without power until you switch off and back on, then setting off much more carefully. If this really is a matter for concern, you could ask if it could be supplied with the NiMh battery and charger instead, this being available with some other eZee models. That type just delivers power without cutting out, but have slightly less capacity and need more attention to the way they are charged.

I have no experience with Powabyke's newly introduced Lithium battery, but it's likely these remarks apply to that as well, it being the technology that has the characteristics, not the manufacture.
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Following advice from Flecc I emailed James at 50 cycles for further clarification. He replied very quickly with some very informative information which I think is worth sharing. Wondered also if anyone would liketo comment?

"The majority of times this happens is with the torq due to the motor in
there being designed for the quando. We have had no reports of the new
fortes and forzas cutting out on hills due to the better gearing and the
smaller wheels and also a higher cut off point on the batteries for the last
two months. I understand from flecc that the nimhs do peform better on hills
than the lithium but have no experience myself of this, we are able to give
the option of both batteries if required, but if you do require nimh let us
know as soon as possible as we only have limited numbers coming over." 50cycles

 

[flecc]

Although it's true that this has been most common on the Torq due to it's high geared motor, the fundamental problem is the failure to deliver enough current at times of high demand, and it has happened at times on my Quando when under high load, and has also been recorded on a Sprint.

The Torq motor's maximum consumption under load is 576 watts, the Forte motor's maximum consumption under load is roughly 680 watts, some 18% higher, so the potential for cutout clearly exists, but that doesn't mean it will happen. The wheel size isn't relevant as a comparison since the two bikes use different motors with different internal gearing, and the change in the cut-out point is another variable.

This cutting out tends to occur as a battery ages, and my experience has been of it occurring after about six months of use. Since the F series haven't been around very long, there's insufficient evidence to know the scale if any of this problem, but if a Forte is used on a long climb of over 10% on full throttle with insufficient pedalling help, the Li-ion battery could cut-out, since it will be unable to deliver 680 watts continuously, despite the claims to the contrary. After all, if it could deliver 680 watts continuous, cut out on the 576 watt maximum Torq would be impossible. However, this is qualified by the fact that the Forte is restricted to the 15.5 mph legal speed, automatically meaning less loading on the motor which could prevent cut-out problems, so it's impossible for me to be definitive, thus I can only warn of a possibility on present evidence.

If used on long and/or steep hills with less than full throttle as I've indicated, accompanied with pedalling help, there could well be no problem with the consumption held at a more reasonable level.

In summary, if in your position I would definitely buy the Forte, but be inclined to play safe with an NiMH battery and charger for your steep hills, based on my experiences with three of these Li-ion batteries and the three NiMh batteries I mainly use now. There would be an almost imperceptible reduction in performance, but the battery would last very much longer and lose less capacity annually. And it would never cut out on a long steep hill.

However, if 50cycles were prepared to guarantee to change the battery and charger to NiMh if problems were experienced within six months, it would be worth trying the Li-ion option.
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[musicbooks]

cut out issue revisited

This cutting out tends to occur as a battery ages, and my experience has been of it occurring after about six months of use. Since the F series haven't been around very long, there's insufficient evidence to know the scale if any of this problem, but if a Forte is used on a long climb of over 10% on full throttle with insufficient pedalling help, the Li-ion battery could cut-out, since it will be unable to deliver 680 watts continuously, despite the claims to the contrary. After all, if it could deliver 680 watts continuous, cut out on the 576 watt maximum Torq would be impossible. However, this is qualified by the fact that the Forte is restricted to the 15.5 mph legal speed, automatically meaning less loading on the motor which could prevent cut-out problems, so it's impossible for me to be definitive, thus I can only warn of a possibility on present evidence.

If used on long and/or steep hills with less than full throttle as I've indicated, accompanied with pedalling help, there could well be no problem with the consumption held at a more reasonable level.

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Thanks for your comments Flecc,
I've had a look at the two sets of hills I would have to negotiate. The first is North Road, Bath 0.30 miles @ 10% 0.20 mile @ 7% 0.15 miles @ 5% Total = 0.70 miles

The second is Snow hill + Fairfield Road 0.15 miles@ 12% + 0.1 miles @ 5%

In between approx 1 mile flat

So, relatively short distances.. Had a look at Bathwick Hill and decided to avoid - 1.5- 2.0 miles @12%!!

Is cut out still an issue on my chosen route?

 

[flecc]

I doubt if there would be a problem on those hills if you made some moderate contribution, especially if you avoided sustained fullly open throttle. In fact on that bike you wouldn't need full throttle on those hills to climb them at a good speed.

Bathwick Hill was the sort of thing I was thinking of with my earlier advice, and the couple of other similarly steep ones close by. You're definitely wise to avoid them. When brand new and with Li-ion battery fully run in, the bike probably could handle Bathwick on near full throttle, but in a few months it could start the cutout problem due to the length and steepness of that climb.

As that's not a problem for you, no reason to hold back now, though the Li-ion life is unlikely to be as long as the NiMh.
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[musicbooks]

Thanks Flecc,
I think I'm getting closer to a decision.. Once again solid advice

Tom
musicbooks

 

[Fat Girl]

Li-ion cut-out on hills

I doubt if there would be a problem on those hills if you made some moderate contribution, especially if you avoided sustained fullly open throttle. In fact on that bike you wouldn't need full throttle on those hills to climb them at a good speed.

Bathwick Hill was the sort of thing I was thinking of with my earlier advice, and the couple of other similarly steep ones close by. You're definitely wise to avoid them. When brand new and with Li-ion battery fully run in, the bike probably could handle Bathwick on near full throttle, but in a few months it could start the cutout problem due to the length and steepness of that climb.

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Flecc, what you describe is exactly my experience with the ezee forte.
I climb up Crawley hill - a 12% for about 3/4 mile and Spring Hill which climbs for 2 miles with 3 short steep sections about 10% each. I found the Li-ion cut out on full throttle with me pedalling. It stays in the amber range when I use partial throttle and pedal in 1st gear. I have to rest once or twice on the way up each way - for me and the motor. I manage speeds of between 4 - 9mph this way.
Taking your advice, I will get a Nimh battery next time

 

[flecc]

That matches my experience on long hills with similarly steep sections, and I've found NiMh to be the only answer. During continuous loading the Li-ion gradually tires and gives less and less current, and after about 3/4 to one mile of climbing with a fairly new battery, it cuts out. A the battery ages, the first cut out happens earlier.

That happens however hard one contributes effort, and I say that as someone who has cycled these same hills for years without assistance and can still climb a fairly short 14% without power on a standard Torq with dead battery.

Obviously the rider's ability determines how much of a problem this is, but it's unavoidable that it is a problem on higher powered bikes.
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[fishingpaul]

i think we sometimes underestimate. just how much battery power a hill can use, when extra energy tested a sprint they acheived 20.8 miles on their mixed route (mainly flat). but just 4.8 miles on their so called mountain route (with hills of just 7% and 8% very quickly draining the battery).if you ride for several miles and then encounter a steepish hill, and are are a little overweight as i am, this will affect distances even more, with even nimh batterys cutting out on hills.but still having enough power to ride on the flat.

 

[flecc]

with even nimh batterys cutting out on hills.but still having enough power to ride on the flat.

They won't cut out in my experience of eZee NiMh batteries. The eZee models and NiMh batteries I've used can be driven to a motor stall standstill on a steep hill without cutting out, even the Torq which is the most demanding of all the models.

If an NiMh battery cuts out, either it's almost empty, or is faulty, or the bike's controller is playing up.
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[Ian]

Like Flecc I have never experienced a cut out with NiMh on either my Sprint or Torq other that with a completely flat battery, even in the most challenging terrain where the motor stalls despite the best efforts of man and machine.

 

[UrbanPuma]

I find when riding in pedal assist mode, using a higher gear such as 4th or 5th to tackle hills, reduces the chance of cut outs under load.

Worth a try for all those experiencing hill cut outs with lithium batteries

 

[nigel]

Nigel

As flecc
and others have said these electric bikes are not mopeds since i had my torq i always pedel. Then you should always then have plenty left for those steep hills