Torq battery dilemma

[carpetbagger]

i might take you up on that when my battery dies

 

[fcurran]

reading between the lines is it possible that the same problem could arise on the powabyke lithium ?

So far tests have not shown any signs of cutting out. Powabyke have been doing Lithium batteries now for over 12 months and feedback has been fantastic. I use a 24 speed commuter with lithium and confess to being very lazy when it comes to charging the battery itself. Living in Bath (for those who haven't had the pleasure of visiting this beautiful city!) it is situated in the middle of a valley so wherever you go you will encounter hills of various lengths and inclines. I weigh 15 stone and have had no problems with the battery cutting out at all on any of the hills. I use the power at all times but admit I enjoy pedalling so I do take some of the strain off the battery. I have cycled up North road to the university and also Bathwick Hill to the same destination. Now these hills are steep and circa 1 mile long.

I would be interested to know if anyone has had cutout on a Powabyke Lithium battery.

I hope this puts your mind at ease Carpetbagger!

Regards

Frank
Powabyke Ltd

 

[flecc]

Thanks for the quick response Frank. If you can climb those wicked hills up to the university, I'm reassured that there's nothing wrong with those batteries and their management.
.

 

[gkilner]

That is good to know Frank. I would like a lithium battery but the price is still too hard to swallow!

Off topic(Sorry) Frank, have you ever had the need to use your bottom 16 gears on your 24 speed commuter? I only ever use the top 5 gears - and I encounter many long and steap hills. The 24 gears seem a complete overkill. Although, if the battery ran out, I could see the advantage of them then.

 

[fcurran]

That is good to know Frank. I would like a lithium battery but the price is still too hard to swallow!

How far do you travel on a single charge? We now have a Lithium Lite battery which does about 10 miles unassisted or 15 assisted which cost £200. Weight is just 2.5kg.

Off topic(Sorry) Frank, have you ever had the need to use your bottom 16 gears on your 24 speed commuter? I only ever use the top 5 gears - and I encounter many long and steap hills. The 24 gears seem a complete overkill. Although, if the battery ran out, I could see the advantage of them then.

Ha! I have to admit, even with the hills of Bath I have used probably just 3 of the 24 gears!

 

[fcurran]

Sorry, Im still getting used to posting messages on here! I meant to ask ...

How far do you travel on a single charge? We now have a Lithium Lite battery which does about 10 miles unassisted or 15 assisted which cost £200. Weight is just 2.5kg

 

[frank9755]

That lithium battery performance is impressive, Frank. It shows that the technology can be made to work in an electric bike application. I guess Powabyke, being based in one of the hillier parts of the country, might be expected to put a bit more emphasis on this than others.

On my Powabyke I also just use the top three or four gears - apart from a couple of occasions when the battery has been close to empty. On those occasions I have appreciated the full gear range. Despite its weight (and I have the full fat, steel and lead acid 39kg version, with 21 gears), that megarange + small chainwheel means I've been able to pedal it up some very steep hills, albeit at sub-walking pace.

I've tended to look on the Powabyke as having 3 or 4 gears for normal use and 17 or 18 'get me home' gears!

Powabykes have not necessarily been the most fashionable of electric bikes but I've always felt they are not only practical, but well-designed to meet the needs of a particular customer segment at a keen price-point, as well as well marketed and supported.

Frank

 

[fcurran]

That lithium battery performance is impressive, Frank. It shows that the technology can be made to work in an electric bike application. I guess Powabyke, being based in one of the hillier parts of the country, might be expected to put a bit more emphasis on this than others.


Powabykes have not necessarily been the most fashionable of electric bikes but I've always felt they are not only practical, but well-designed to meet the needs of a particular customer segment at a keen price-point, as well as well marketed and supported.

Frank

Ha! I must admit they won't win any awards for style! but as you state they are well built with strong motors and indeed do the job with minimal fuss. Now that we have a good, reliable lithium battery we are in the process of designing 2 new bikes built specifically for a lithium battery which will hopefully be available early next year.

 

[gkilner]

Sorry, Im still getting used to posting messages on here! I meant to ask ...

How far do you travel on a single charge? We now have a Lithium Lite battery which does about 10 miles unassisted or 15 assisted which cost £200. Weight is just 2.5kg

I travel approx 13 miles each day so the light version might struggle to last the distance, especially if the capacity drops off over the months.

I've just thought though, with it only been 2.5KG's I could easily carry it to my office for a charge before riding home.

 

[fcurran]

That is always an option for you especially as the charger is probably 1/3rd of the size of the current lead acid chargers and fits in the panniers with plenty of room for your sandwiches!

 

[Tiberius]

Hi Guys,

Thanks for all the useful posts. The strong message coming over here is that the eZee Lithium batteries are not very good, but that other manufacturers are supplying good Lithium batteries. Is that a fair summary?

We have plenty of reports posted here about the eZee failings. We have one report that the eZee batteries are wonderful, but that comes from the manufacturer.

So just to be fair and scientific about this, I should ask just how good is the evidence that Powerbyke, Whisper and others are doing it better. Does anyone have any quantitative data or test reports? Has anyone had problems with them?

Nick

 

[HarryB]

Hi Harry,

I take it your new battery is a Li Ion. You say the sooner you get NiMH the better, but surely what we would really prefer is a Lithium that was actually reliable.

What's not clear to me at the moment is whether all Lithium batteries have turned out to be a disappointment on e bikes or just some of them.

Anyway, I have just fitted a Cycle Analyst from ebikes.ca so that I can get some quantitative measurements of current voltage and Ampere-hrs rather than the more subjective observations on distance and gradient.

Nick

I actually don't mind what it is or even how much is costs to buy (within reason of course). I want a battery that lasts at least two years (at my usage) and costs not more that £100 a year when averaged over its lifespan. When it starts to deteriorate I want it to gradually lose range not become a useless hill climber because of the constant cut outs. As I have an Ezee bike it seems the only battery that will work for me is NiMH. If it turns out other manufacturers do not have this problem because a. they use better cells and b. they have a better BMS then Ezee will be taken off my short list when I come to replace my bike. I am sure there will be others who will feel the same when they realise that the battery has only 100 charge cycles before it becomes unbearable to use on hills (rather than a claimed 500). Ezee and 50 cycles may want to take note of this. The guarantee says it all - they cannot even guarantee it for a year at 80% depth of discharge.


PS One caveat to this - if you use your electric bike locally and never go more than a mile before re-charging then the li-ion will last a long time. But this wouldn't suit me.

 

[carpetbagger]

Thanks for the reply frank powabyke,i have just put some more pennies in my piggybank !. I know powabykes claims for the lead acid were correct as i have achieved 32 miles which included some hills,so i was just after some real feedback on the lithium.As for the gears,on my 6sp euro the lowest i have ever used is 2nd on one mega steep hill....there are lots of them up north !
thanks again

 

[flecc]

So just to be fair and scientific about this, I should ask just how good is the evidence that Powerbyke, Whisper and others are doing it better. Does anyone have any quantitative data or test reports? Has anyone had problems with them?

Nick

I don't think it's the case that the eZee battery is necessarily dud, and the much longer life I got from the very efficient Q bike over the Torq is a clue to that.

The problem is mainly that eZee have some of the most powerful motors in e-biking, and at full throttle they give the battery a pounding, something that no-ones Li-ion enjoys. Some suppliers openly acknowledge the unsuitability of lithium with high power demand by only supplying NiMh with their most powerful motors, Cyclone being one such supplier.

There is an answer in part by using the techniques that the most successful with Li-ion like Panasonic and BionX use, more software control to keep the power demand in strict check, but that would compromise the high power appeal and remove some of the point of the eZee models.

That this rigid control is the answer though is well illustrated by the satellite use I've referred to before. Perfectly ordinary Li-ion cobalt batteries are launched to do a 10 year duty cycle with over 3600 charges. How? They only use one seventh of their capacity once each 24 hours, and that usage is identical every day. They also have identical recharge of that one seventh every 24 hours, and each of those at exactly the same time in each day. In those chemically ideal conditions, long life is made easily possible.

On a powerful throttle controlled bike with low level software control, the rider can and does provide the complete opposite, huge variations that both overload and give the chemistry little chance of settling. Clearly the rider needs to be taken out of the equation more with these batteries, something better software control can do.

A larger capacity/larger cathode eZee battery would help a lot, a route that Wisper took with the 14 Ah battery, since they too had cut out incidences on their most powerful bike at the time, the 905e. To get that larger capacity within the same space demands the reuse of cobalt cathodes, very unpopular after all the publicity over fires in these. Wisper's supplier, Lishen, got round this in part by using a hybrid Manganese Cobalt cathode, but as we've heard from David of Wisper, they're now returning to the lower capacity 10 Ah size, but with improved battery management, exactly as I recommend above.

I would have liked to have seen a slower transition from NiMh to lithium, but the latter proved so good in small applications that there seemed little reason not to switch.
.

 

[Tiberius]

Thank flecc, that is very useful info and background. I think it is important there to get an idea here of how eZee are doing relative to others. As Harry says I hope they and 50 cycles are taking note of this; it would be nice to get some dialogue with them too.

Now I've got the Analyst on my Torq I can see what the power and current being delivered are, and yes they are pretty high. Another thing with the Torq particularly is that when hill climbing the motor is bound to fall below its optimum speed and the current will therefore be larger than necessary.

Maybe you are right that we shouldn't criticise the eZee Lithium battery as being worse than other Lithiums, but then perhaps we should be saying it was bad engineering design to put that battery on that bike.

Nick

 

[flecc]

You've got it dead on Nick.

The Quando 20" wheel motor in the Torq's 28" wheel is too high geared for it's own good, with many riders spending half it's life at or below 12 mph, which doesn't give the battery a chance being so much of the time on maximum drain.

Of course all the eZee models except the F series were designed for NiMh and in one case, SLA (Rider, later Liv model). It was on the promises of the battery manufacturers that they optimistically adopted Li-ion, only to be stung by the outcome. The trouble is that it takes many months for the problems to emerge, by which time the situation can be committed in this fast growing market.
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