Trek Cytronex - First Impressions.

[Mark/Cytronex]

Battery

I have just spoken to John and the problem is as follows:

It is very important to follow the instructions we provide for conditioning the battery which are as follows: The battery must be fully charged the first time, then used continuously until assistance runs out, and this needs to be repeated three times in one go. The battery does not achieve its full potential until this has been done.

John apparently did not charge it the first time, and has used it in bits and pieces since. I think probably the problem was that there was a large gap between my handover and John being able to use the bike because of his hand. We have had heavier and I am sure weaker cyclists than John on our bike and they have achieved 20 miles.

Actually NiMh batteries lose the most charge in the first 24 hours and from then on this slows down to a tiny self discharge, taking 6 months at least to totally self discharge. So to get the maximum range the way to use our battery is to charge it fully just before use and take the bike out at the end of the fast charge. This is why we have a fast charge of only 1 hour 30 minutes for a full charge from empty.

However, the batteries must be conditioned first and it is very important that this is done at the start!

Regards,

Mark

 

[Cyclezee]

If All Else Fail, Read The Instructions

As you can see from his post, I had a conversation with Mark.

It could be me After having spent a few minutes reading the instuctions carefully, it appears that I have not been conditioning the battery properly

In the DO section it states "Recharge the battery fully before first use. The the instructions go on to say "Use the assistance on your bicycle the first 3 times until it expires and then fully recharge the battery each time.
Discharging and fully recharging the battery 3 times in this way will amximise its power and capacity. Please note that you will not experience the full range of the battery until this has been done"

What I did yesterday was just ride it with the charge that was left and got 2 miles. Then I put the battery on to charge and rode for 13.5 miles, with a couple of 5 minute stops to pop into shops, before it expired. Then recharged it when I got home.
Today, I rode it for 6 miles this morning on another shoping trip then came home. this afternoon I went out again and rode 5.5 miles before the battery expired, that made a total of only 11.5 miles.

What I intend to do tomorrow, weather and wife permitting, start the conditioning again by riding continuously until the battery expires. Then do this another 2 times. This should fully condition the battery.

The instructions also state that using the battery just after it has been recharged and still warm will maximise power and range.

Hopefully this will resolve my problem without having caused damage to the battery.

J hn

 

[flecc]

Actually NiMh batteries lose the most charge in the first 24 hours and from then on this slows down to a tiny self discharge, taking 6 months at least to totally self discharge.

Regards,

Mark

We'll see what John reports in due course, but it's extremely unlikely to almost double capacity. Twenty per cent is more likely.

However, what you've said above is somewhat misleading in this context. The loss of charge in the first 24 hours is not sufficient to make any appreciable difference. The peak voltage following the charge is what initially drops rapidly in a matter of hours, the rate dependent on ambient temperature.

The hydrate self discharge drops the remaining battery content to the unusable level well within three months, and the vestige at four to six months is academic.
.

 

[flecc]

P.S. Just saw you post John. You wont have harmed the battery, just delayed getting full capacity.

Using the battery straight after charging when still warm utilises the excess voltage of the cells at that point for a higher performance (speed), not appreciably more range. If that isn't used immediately before cooling, that performance boost is lost.

None of this is different from any other NiMh e-bike. The warm battery straight after charge adds 1 mph to my Q bike when on NiMh, but that's lost in about half a mile. so as you see, no miracles.
.

 

[Cyclezee]

Flecc

I didn't think I would have damaged the battery, but thanks for your reassurance.
As I said in an earlier post, it is really too early for me to give a fair and accurate report on the bike.

J hn

 

[flecc]

Just added another bit above at the same time John. It will improve with a further full charge, though as you've now fully charged it once, it's not going to nearly double capacity.

I've no doubt you'll do better with full fitness returned though.
.

 

[Cyclezee]

Day 3

Went out at 7 this morning, battery already charged from yesterday, so couldn't set of with a warm battery.
Weather, dry and sunny, but quite windy, 15 to 20 mph from the SW.
My route will mean nothing to you but I rode from New Bradwell to MK City Centre, 2.5 miles mainly uphill, then down the road parallel to Campbell Park, hit 27.8 mph, power off on all down hill sections.
Then to Willen Lake South, did 3 circuits of South and North Lakes, from there through Willen Village, Blakelands and Tongwell industrial estates to Giffard Park where I joined the Railway Walk back up to New Bradwell. Still had power left, so kept going up and down the Railway Walk untill it expired at exactly 17 miles.
A significant improvement on yesterday. I stayed in low power all the time, rode without stopping and pedaled continuously except when freewheeling on downhill sections.
I don't think I will be going out again today, the wind is getting even stronger and I don't have the time as I would imagine the range next time might be 20+.

J hn

 

[flecc]

Fair enough John, keeping it on low power all the time and power off at times, 17 miles. I don't realistically see further capacity gain after the full charges/discharges you've done, though there might be a fraction.

It emphasises what I've said before though, primarily a cycling bike with some power assist, and that isn't how the majority of e-bike owners use their bikes.

After all, I've showed the same with the Kalkhoff Agattu. On test on a moderate route and using standard power mode only, switching off when the going was easy, I was able to demonstrate a 50 mile plus range capability. But I didn't then claim that most riders would easily get that as has been done here, instead I forecast a range of around 35 miles for most, detailing circumstances where more might be obtained. Since I'm 72 and the nearest to an athlete I've ever been was taking part in a losing tug o' war team, one would think most would easily equal what I did.

But now we've seen what a number of owners are reporting in here, the majority getting around 30 miles, a couple less and the odd instance of more. That's all I'm asking for, recognism of most e-bike riders abilities and the resultant realism so that prospective buyers aren't misled. For average users, 4 Ah does not equate to an e-bike range of 20 miles, nowhere near.
.

 

[Mark/Cytronex]

Battery use

Cytronex owners will need to follow our guidelines, in order to maximise the range and power from their batteries. In addition to the conditioning phase already mentioned, the Cytronex battery is designed to be charged and used the same day, and this is why we have such a fast charge. Doing this will maximise both power and range.

As already mentioned we are using a different cell to other manufacturers and have developed our pack directly with the cell manufacturer. It packs a large punch in a very small size. You can of course charge the battery whenever you wish but the maximum distance is achieved when using the bike straight after charging.

Our system achieves an excellent range from the size of battery exactly because it is not like other ebikes: it is very light, used on bikes with fast efficient geometry, and has a very efficient motor. Basically it is a whole new concept in electric bikes, and people seem to like it that way!

Regards,

Mark

 

[frank9755]

Mark,
I like your product and have not ruled out buying one at some point in the future but, if you'll forgive me, I feel your previous post was just a little vacuous. NiMH batteries are a fairly mature technology. Their performance characteristics and Energy density and well understood. There are several people on here who have demonstrated that they know much more about it than I will ever know, but I find the assertion that your batteries are in some unsubstantiated way, 'different' to be less than reassuring. You've stated how big your batteries are, in Watt hours, and that, surely, defines what they can deliver?

 

[stokepa31_mk2]

I think the key point here is that you can't argue with the physics. a 4ah battery is not going to cut it for 20 miles with the average ebike rider on that motor. Those people who can keep the bike moving at a high speed will get the 20 as the demand on the battery will be less.

This bike will suit the more athletic rider or those willing to spend the extra on a second battery which is quite reasonably priced or those who want a more fashionable bike looking product.

The charging directly prior to use seems a bit gimmicky to me as this is a natural trait of this cell and may boost power for a short while but will do little to add to the range.

I still think this bike is very nice looking but on closer inspection I fear it may be slightly flawed.

These things tend to evolve and perhaps a higher capacity battery could be needed

 

[Mark/Cytronex]

The "big punch" of our battery is that it uses a high drain cell which can provide a lot of power, and therefore torque, in a very small size. This is the same reason why it can recharge so quickly. Some will like that, some won't. There is not just one type of NiMh cell there are a great many, for different applications.

The big range, as I attempted to explain below, is because our bike is very light compared to other ebikes, does have a very efficient motor and uses a proper bike.

In the end our bike will appeal to some ebike enthusiasts but not others. If you are looking for something more like a moped, you should look elsewhere. It is simply not designed for that.

Our target market is younger than the average ebike user today, as we want to try to persuade the very large number of car only users to do their shorter journeys by bike. To achieve this our product provides all the fun of cycling, without the hard bits. For those who already cycle it means they can get to their destinations faster than ever before.

Hopefully, if we achieve this we can do our bit for climate change. Not everyone wants a 30 mile range and clearly those who do won't be buying our product. For those who have shorter journeys and want a normal bike but would also like help when the going gets tough, Cytronex is ideal.

 

[flecc]

It's very easy to harm your prospects with the wrong type of promotion Mark, and I honestly think you are doing that with the pseudo science about your NiMh battery. As other's have said, content is content, and pixie dust doesn't make it go further. High discharge rate cells just give the opportunity to empty the content more quickly and potentially shorten the range.

I don't like you publicising in this way precisely because I want you to succeed with what is obviously a very fine product for the right user. Your last two paragraphs repeated below have it just right, and if you stick to that no-one can question the publicity. It really is best to leave pseudo science to the likes of L'Oreal and Actimel:

Our target market is younger than the average ebike user today, as we want to try to persuade the very large number of car only users to do their shorter journeys by bike. To achieve this our product provides all the fun of cycling, without the hard bits. For those who already cycle it means they can get to their destinations faster than ever before.

Hopefully, if we achieve this we can do our bit for climate change. Not everyone wants a 30 mile range and clearly those who do won't be buying our product. For those who have shorter journeys and want a normal bike but would also like help when the going gets tough, Cytronex is ideal.

.

 

[Matt]

Regarding the range issue, I think the style of the bike makes it fairly clear what sort of customer it is aimed at. This being people who have used a bike to commute before or have a degree of understanding of what makes a decent road/commuter bike. So I think the majority of people who purchase it are expecting to have to put a fair amount of effort in and will get the stated range no problem. Of course there'll always be people who made an error in purchase and were expecting the bike to do all the work. Therefore I don't think it fair that a supplier would have to declare a range that someone so unsuited by the setup of the bike would get.

I'm personally glad that it only comes with a small battery as my commute is well within it's range and I would hate to have to pay £300 for a huge lithium battery that I'm only going to use a fraction of the capacity of and that would need replacing in a couple of years almost guranteed.

What makes this setup super cool is that they could create a whole range of bikes using this kit without the huge R&D costs of building a bike from scratch.

 

[john]

As already mentioned we are using a different cell to other manufacturers and have developed our pack directly with the cell manufacturer. It packs a large punch in a very small size.

I guessed that the cells are a little different to others given what you said before. It should be noted that 4Ah of capacity from one battery may not deliver the same amount of energy (watt-hours) to a bike motor as 4Ah from another battery. It may be that your battery is providing more than typical in this respect.

 

[flecc]

I guessed that the cells are a little different to others given what you said before. It should be noted that 4Ah of capacity from one battery may not deliver the same amount of energy (watt-hours) to a bike motor as 4Ah from another battery. It may be that your battery is providing more than typical in this respect.

Noted, but what I've posted refers to the best product available, not comparing with inferior cells.
.

 

[fishingpaul]

Is the stated range using low power mode or high power mode.

 

[Mark/Cytronex]

Spot on again Matt and as it happens I have just been out testing our second model, which is the Trek 7300 (which has suspension forks and hybrid tyres), will have some pictures soon.

Although I generally like road speed, I must say that it is extremely comfortable to ride and on a Sunny (but windy) Sunday afternoon, cruising along effortlessly was just wonderful.

Just seen John's post which is clearly a very good point. When we were deciding which cells to use we tested a number of different makes and models. The first NiMh cell we tested had a higher capacity rating but delivered 1/4 less range. When we looked into this we found that many cells never deliver their actual capacity because they can only do this at lower currents. When discharged at high currents (on hills) their capacity suffers greatly. We also tested a finished 9Ah Lithium Ion ebike pack which delivered an average of only 23 miles on the bike, compared to 20 on ours.

 

[Mark/Cytronex]

The range is based on an average from a variety of different routes and using low speed on steep hills and high speed everywhere else, except when the bike is naturally going faster than the maximum assisted speed (e.g. downhill).

Regards,

Mark

 

[Chris_Bike]

Well I've been at a bike race all today so have missed the foregoing debate. We took only Lynne's bike as we didn't have room for two.

The race was at Haworth (Tom Simpson Memorial Race to any who might remember him). Lynne rode around the circuit several times, which included some decent hills and, most significantly today, 40 mph head winds in places. She completed 17.2 miles and the battery was still going. I don't know how much it had left in it - I considered taking it out again to run it down but opted for a glass of wine instead! Jack finished 13th.