Torq with battery mod storms up hills

[Tiberius]

Hi James,

Unfortunately, I don't have accurate info on the Li battery's actual performance before the mod. Reports based on mileage, cut outs and which LEDs are showing can be subjective.

It would be nice if the experiment could show that it also stopped the loss of life of the Li battery, but to show that properly would require doing it on a group of batteries and also having a control. That's a bit beyond the scope of this experiment for now. But if eZee or 50 cycles want to co-operate.......

Nick

 

[flecc]

While not stopping loss of life, there's every indication that this technique could extend life due to the destressing effect of the support. Li-ion batteries which are regularly part charge-cycled throughout their life can last for many years, and this supporting system is a move towards a similar low stress climate for the Li-ion cells.
.

 

[Cyclezee]

Has anyone thought of trying to replace an Ezee Phylion with a Wisper Lishen 14Amp battery, don't know how technically difficult this would be.
I have owned and ridden an Ezee Torq and 905se (Including the Torq now owned by Tiberius). In my opinion the 905se is much better at hill climbing with none of the cut outs experienced on the Torq.

John

 

[flecc]

I have queried this John, but haven't been able to get the dimensions needed to see whether the cells and circuitry would fit in an eZee case.

The potential is there, but there's no guarantee that cut-out wouldn't occur, the motor and battery cut-out characteristics might not match. Probably best if just the cells were transferred onto the eZee battery circuitry, no mean task though.
.

 

[Cyclezee]

I have queried this John, but haven't been able to get the dimensions needed to see whether the cells and circuitry would fit in an eZee case.

The potential is there, but there's no guarantee that cut-out wouldn't occur, the motor and battery cut-out characteristics might not match. Probably best if just the cells were transferred onto the eZee battery circuitry, no mean task though.
.

Didn't think this would be easy, but I'm pretty sure Tiberius could do it if anybody could.
Another alternative solution could be to adapt a Torq to take the Lishen battery case.

John

 

[Tiberius]

It could always be done, if it is a 36V battery, the question is more whether it could be done neatly.

What's the cost and availability of the other battery?

Nick

 

[flecc]

Still not listed Nick. They sell battery and charger paired, the 10 Ah one at £285, so I assume about £350 to £370 for the 14 Ah.

Similar 3.7 volt cells, and the electronics are transferrable ok as you'll see on my site here, but just a very fiddly job.

The cell size is likely to be a stumbling block though. If they are much fatter, the eZee frame aperture might not take them.
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[Tiberius]

I don't think I'd want to take on re-packaging the cells, so it would be an inelegant solution, such as the new battery on the rack. Anyway, I have other problems to deal with.......

I tried another long test ride, but immediately had problems. It went to a red light quickly and then started a series of cut outs. The bike had been charged but then left in the dry for a week and a half while I had visitors over the holiday period. I wondered if the batteries had lost some of their charge.

The cut outs were followed by 8 flashes of the controller LED (Hall sensor problem). After 3 Ah and 9 miles I gave up.

Back in the workshop the 8 flashes had changed to 12 (controller broken). I opened up the indicator box on the handlebars and the wiring to the throttle and the motor, cleaned and dried these and it behaved again, so I think the main problem was spray off the wheels. But the Li battery took over 3 hours to charge, which doesn't seem right. I don't think any of this is related to the battery mods, but in case it is, rather than start a new thread, I will ask the questions here:

Is the bike wiring really that sensitive to water?
Can that be normal for a Li battery?
Where do I get some mudguards? Is it better to try to get the manufacturers ones (50 cycles haven't replied to requests) or ones from a local bike shop (there is no LBS here, so mail order recommendations would be useful)?

Nick

 

[HarryB]

Is the bike wiring really that sensitive to water?
Can that be normal for a Li battery?
Where do I get some mudguards? Is it better to try to get the manufacturers ones (50 cycles haven't replied to requests) or ones from a local bike shop (there is no LBS here, so mail order recommendations would be useful)?

Nick

Yes I am afraid it is quite sensitive to water ingress particularly the meter circuit board. Shows up as brake lever cutout problem but I have long since removed those brake levers, but apparently it can apply to other parts of the wiring system as well. I have had a couple of disrupted journeys with that one. I sprayed some WD40 into the case as a last resort which has cured the problem but is not an elegant solution. It did show the problem was with the damp circuit board rather than the wiring itself.

The controller can be sensitive to the wiring to/from the hall sensors - any sort of dirt on the contact can cause the 8 flashes in my experience. Doesn't happen very often and I have never had 12 flashes which would scare me.

SKS do some good full mudguard - easy to fit and available from Wiggle. SKS Chromoplastic Mudguard Set for £23.99 | SKS Mudguards | Cycle | Wiggle Plenty of self amalgamating tape would be useful as well!

 

[Tiberius]

Thanks Harry,

Interesting that that circuit board is so sensitive. I should have some special coating around that I can try on it. I have used self amalgamating tape on some joints already, and I also use adhesive lined heat shrink tubing if a joint has to be remade. Looks like a wiggle order coming up.

Nick

PS 12 flashes is difficult to count. Could be 13 which is more scary.

Update: Display circuit board sealed with conformal coating, joints sealed, and it all seems to be working again.

 

[JamesC]

Details of the Mods.


So I took the view that the answer was not to change the battery type - Lithium offers the best energy/weight ratio of the types available - but to try to deal differently with the peak current demands.

I set up a system that augments the 10 Ah Lithium battery with a smaller auxiliary battery. The idea is that they will share the peak currents, but because the auxiliary is only required to contribute to the peaks, it can be a much smaller battery.

Two or more battery packs can be readily combined with Schottky diodes - this allows either or both to power the motor according to the state of charge, and prevents cross currents between the batteries. With a Schottky combiner, the main and aux batteries can be different types, so the obvious type for the aux is NiMH, which can give high currents from a small size - such as AA.

This solution with the small auxilliary NiMH packs is very effective for getting the maximum from the Li-ion battery.

For longer rides using Li-ion on the Torq, I am in the habit of taking a spare Li-ion battery along in a saddle bag, and changing to the fresh battery when the first begins to tail off

Does it make more sense to simply use the two Li-ion batteries wired in parallel, if the use of the bike is more for longer distance touring (including hills) ?


If so, I have been wondering whether the main internal wiring in the Ezee Li-ion battery already travels down the full height of the battery from the fuse area down to the power outlet connector at the base.

This might enable an auxilliary socket to be added at the top of the battery for connection to a second battery in the saddle bag when required.

What are the pros and cons of this approach ?

James

 

[flecc]

The internal wiring is from the top, and using two in parallel should overcome any cutting out problems and lead to longer battery life as well, stressing the cells less.

The natural aging of li-ions would offset that life gain though, so I doubt if there'd be any economic benefit.
.

 

[Ian]

I'd reccomend paralleling the batteries through schottky barrier diodes as the batteries internal management electronics may not take kindly to a voltage from another battery on the output side. The battery wiring is easily accessible behind the bottom bracket with the bike inverted and this would be a good place to tap in with diodes, the connections to the seccond battery could be made with pins from an old 13A plug.

 

[Tiberius]

Does it make more sense to simply use the two Li-ion batteries wired in parallel, if the use of the bike is more for longer distance touring (including hills) ?
James

Hi James,

This is exactly what I would do. It is the obvious thing to do and I was going to post that in due course. At the moment though, it is only a theory that this is better for the batteries in the long term - there is no experimental confirmation yet.

But it is clear that it makes the bike better to ride, and I can see no downside. Even if it isn't remarkably better for the batteries, it can certainly be no worse. So, if you are carrying a spare battery, then, yes, it would be better to wire the two batteries in together rather than use one at a time and swap them over.

It should be done with a Schottky combiner so there is no problem with charging them separately, or even using different types. As for implementing the wiring inside the battery case, I am doubtful. It would be better to leave then batteries as they were and do the wiring on the bike.

Nick

 

[JamesC]

Many thanks for the advice.

Please would you suggest a type and source for the appropriate Schottky diodes. Given the type of weather they will get down by the bottom bracket, do they need to be encased ?

I can see the good sense in isolating the two batteries with diodes, but I guess that it always comes at the cost of half a volt or so due to the forward voltage drop across the diodes.
Is the half volt drop in performance due to diodes a small penalty compared with the overall issues with a single battery ? I guess so.

James

 

[flecc]

At the moment though, it is only a theory that this is better for the batteries in the long term - there is no experimental confirmation yet.

Nick

I have to differ on this Nick, since there are years of evidence in usage in space and e-bikes.

The newest evidence in this forum and via the odd PM is that 18 months of Torq operation shows that higher discharges equal shorter life, ranging from my worst case of derestricted Torq usage in a very hilly area producing failure at around 60 full charges in two batteries, to East Coast flat area users with typically one quarter of maximum discharge rates achieving the highest number. Between those have been cases of around 100 charges and some at well over that, all correlating to the territory and type of use.

Panasonics much longer experience of Li-ion in their own bikes with low to moderate discharge rates prompts them to offer a two year warranty, while satellite Li-ion usage over many years at low discharge rates produces 500 and more full charges, reaching and surpassing the theoretical maximum figure.

So there's a clear correlation between discharge rate and life. Since using parallel batteries doubles capacity and therefore halves the per cell discharge rate, longer life will result, up to a maximum of around or above the theoretical limit of 500 charges.
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[Tiberius]

So there's a clear correlation between discharge rate and life. Since using parallel batteries doubles capacity and therefore halves the per cell discharge rate, longer life will result, up to a maximum of around or above the theoretical limit of 500 charges.
.

Hi flecc,

I meant there is no experimental confirmation with this particular battery and bike. I was being cautious, but from what you say, I am perhaps being too cautious. There is every reason to believe it will help the battery life and no theory or evidence to suggest it will harm it. But 60 charges is so far off the 500 predicted that I wouldn't like to claim it will fix that problem without seeing it happen.

Can we say we are both right. I'd love to see a group of people doubling up batteries and reporting the results.

James, I used the 30CPQ100GPBF, a dual diode here from RS
They (I used 2 to allow for 4 batteries) are fixed to a small aluminium plate and then sealed with heatshrink tube and hot melt glue.

Nick

 

[flecc]

On this model bike, certainly 18 months is too short to be definitive Nick.

I've a strong feeling that the answer for e-bikes will lie in battery improvements well before we can get enough people to use parallel batteries over time though.

That's why I'm not doing any more experimental work in this direction, since I'm sure developments are going to defeat any purpose.
.

 

[JamesC]

James, I used the 30CPQ100GPBF, a dual diode here from RS
They (I used 2 to allow for 4 batteries) are fixed to a small aluminium plate and then sealed with heatshrink tube and hot melt glue.

Thanks again. I will get the bits together and report back.

James

 

[Tiberius]

James,

You could get 15 to 20 W dissipated in the diodes, so you need to fix them to some kind of small heatsink. Those particular devices in this application also need their central body part insulated.

Nick