Can you advise a clueless newbie please

[twyfordbridge]

Hi,

Sorry to bother you (I feel like a first day schoolboy walking into a sixth form classroom).

I recently bought (dont laugh please) a 250 watt hub conversion kit with a 24volt 6.8Ahr Li-ion battery pack for my Mountain-bike, more like a gentle incline-bike really !

Performance is sad..... no, tearful is more appropriate, especially having spent hours watching Knoxie zooming around his home town at speeds of up to 27 mph. Mind you, I do leave OAPs in their invalid carriages behind, just about.

Anyway, my query. I often take the bike away at weekends to places where I am unable to recharge the battery (sad caravanner as well).

I was thinking of buying a second battery pack (SLAs) cos I cant afford the Li-ons. I know nothing about electronics and having been slightly conned once about the supposed performance and range of my conversion kit, thought I'd ask you guys for some advice (not "just sell the kit" please)

There is a battery company close to my home (Power-Sonic) in Wickford, Essex who advertise two different 12 volt packs at under £20 each. I was hoping that of them (X2) would be suitable as a back up supply should the Li-ons run out and be unable to be recharged.

Both the replacement options are about 4 kilos each and should not be a problem as I only weigh 10 stone and the rear carrier is quite strong.

I completely baffled by the tech spec and wondered whether one of your members could take a look at the specs and say whether you think one is better than the other for my purposes. One is listed as 12Ahr and the other is 14Ahr.

I will now try and link the spec pages I saved - if they dont appear (cos I'm useless with computers too) the website is http://www.power-sonic.co.uk and the batteries/specs are listed in their dropdown boxes marked Power Sonic and 10 year life batteries.

Thanks very much for a useful forum. (wish I understood half of it !!)

 

[TylerDurden]

Hi,

If you take your car on weekends, you might consider an inverter to run your bike's charger. It could be useful other ways too.

250W is not that bad. It gets me around town fine. Not fast, but fine.

Please tell us more about your bike/kit. Pics would be great.

SLAs are low cost up front, but cost more in the long-run. The last PS battery I got only worked for 9 months.



YMMV...

 

[Ypedal]

If you are looking for batteries to use when you CANOT recharge them after a ride.. avoid SLA... go Nicad or Nimh or ...

But SLA needs to be kept fully charged at all times for long life.

Your lithiums don't care if left un-charged..

 

[xyster]

Performance is sad..... no, tearful is more appropriate, especially having spent hours watching Knoxie zooming around his home town at speeds of up to 27 mph.
...
I was hoping that of them (X2) would be suitable as a back up supply should the Li-ons run out and be unable to be recharged.

Welcome to the humble Endless Spheroid. Are you seeking mainly higher top speed, more hill climbing power, or longer range? You can have all three, like Knoxie, but it gets a lot more costly and/or heavy. Your priorities make a big difference as to your best and most affordable battery upgrade/addition options. And so does your motor and controller's specifications -- which kit did you get?

I agree with ypedal that unless you can recharge right away, you should avoid lead (SLA) batteries.

250W is not that bad. It gets me around town fine. Not fast, but fine.

If that's your Currie, TD, it's really 840 watts (24v 35a) no matter the manufacturer's motor rating -- probably a lot peppier than the 24V 15A kits out there (which I'm wondering if twyfordbridge's is).

 

[twyfordbridge]

Hiya all,

Thanks for your replies and advice. It had not even occurred to me to use the caravans inverter to charge the battery.I will just have to wait till the wife drops off to sleep to unplug it from her TV!.

Seriously though, I dont think I explained my problem clearly. While I am away with the caravan I like to make long trips out on the bike. I have some serious hip problems (osteoporosis) which make heavy pedalling quite painful. The Li-ion pack is good for about 10 miles or so but I am always worried I wont be able to make it back after a trip around the countryside. A second battery pack would alleviate that fear. As I said, I cant afford a lightweight pack so SLAs seemed my only option. It was my intention to carry the SLAs on my rear rack as well as carrying the Li-on.
That way I could simply unplug one pack and change over should the need arise. Now you have pointed out about using my inverter, immediate recharging should not be a problem.

Would the 12Ahr or 14Ahr SLAs, as I mentioned in my original post, give me much of a greater range than the 6.8Ahr Li-on I already have ?
And are the SLAs I mentioned the right type for the job.

Sorry I was not able to post the printed spec sheets. I saved them as PDFs but when I tried to paste them into my original post it just came out with their links to attachments!!!

You asked what type of kit it was. I havent got a clue!
I have just emailed the provider and asked him to send me spec details for the hub and controller.

Here are a couple of pics. Looks pretty mild in comparison to your beasts.

I hope to have the spec details some time tomorrow.

Thanks again for all your help

 

[Ypedal]

The 12 ah sla's are pretty standard, the 14's would provide slightly more range.. but add weight... i think the 12's would do the job for you, with a 250w system they should hold up well... expect similar range from a 12ah sla as your current Lithium pack. Using both packs you double your range.

Can you get B&B brand in your area ? if you can and the price is not too much more.. they are a good brand.. so is Hawker / Odyssey . Not sure what's available in the Uk tho.

You need to know if your lithium is 24v, or 36v, because you will need either 2 or 3 of the bricks to match the voltage. Does the Lithium battery conect to the controller with a special conector ? or regular trailer hitch conector ? this might be a hurdle to overcome.

Do you have a volt-meter ? know how to use it ?

Btw : Nice bike ! .. looks light-weight !... in comparison.. my Chaos weighs 80 lbs !! lol..

 

[xyster]

Would the 12Ahr or 14Ahr SLAs, as I mentioned in my original post, give me much of a greater range than the 6.8Ahr Li-on I already have ?

Maybe a little better, maybe about the same. The li-ion pack should give ~80% of it's rated capacity before your low voltage cut-off terminates the ride -- 5.5ah or so. Under typical ebike use, ebike-sized SLA's like those you posted give about half their rated capacity -- so 6 or 7 real-life amp-hours.

And are the SLAs I mentioned the right type for the job.

Look good to me.

 

[patrick_mahoney]

I'll basically agree with the experts above me. You should expect similar range with a 12Ah SLA as with the lithium-ion pack - perhaps a bit better. Despite the fact that you will be expecting it, the weight will likely surprise you. 2 x 12V 12Ah cells will weigh about 20lbs (9kg). If you want to cut back a bit on the weight (and the range) you could consider 7Ah SLA's. You'd be down in the 12lbs range (for 24V, 7Ah) and would get about 3.5-4Ah out of them.

And I'd also complement you on a very nice e-bicycle. It looks elegant and tidy.

 

[Johnbear]

Nice clean bike, looks great!

 

[knoxie]

Hello

Yes nice set-up you have there! shame you didn't contact me I could have sorted you out with something a little quicker! ha ha, well it looks like a Tonx motor you have there, they are geared brushless hub motors but at only 250W they are a little anaemic, however it should be possible to double the power and still keep it reliable.

If you could take some more pictures of the motor and the controller and post them up I will be able to advise you some more. Stay away from the Powersonic batteries they are cheap and wont give you many cycles, go for Yuasa batteries if you are going Lead Acid, they are by far the best in the UK, and if its only a backup pack you could use a 6AH pack which will be much lighter and should be enough to get you home if all else fails.

I get a lot of mail re my high speed video! seems a lot of people have watched that! I was using Lead Acid batteries then but haven't for about a year now as they don't last at the sort of amps I drain from them, I have been using NIMH packs which are a lot lighter and last 3 times as long, I also have Lipo packs as well but don't use them on that bike.

If you are underwhelmed by your bikes performance though there are options, the Puma motor which is a geared brushless hub motor is really powerful and although not strictly road legal would give you the level of performance that you are after, I am currently running trials on them at power levels of 1,500 watts and they are performing great as you would expect however they are in no way road legal, although they can be made so by the simple flick of a switch if you catch my drift!

Post up some pictures in detail of your bike, but as far as the batteries go I would go for 2 x 12V 6AH Yuasa batteries, you could use the 12AH ones but they are heavy, you can get these batteries from Maplin but they tend to keep old stock, RS is a much better bet as they float charge all their lead acid batteries, you wont find B&B batteries in the UK I have tried its almost impossible, Yuasa are the best ones that are available for a reasonable price.

The RS part number is 320-4508 go to rswww.com and search for them they cost 20 pounds each and weigh 2kg each, they are only 5AH but would get you home no problem, a cheap scooter charger from ebay would charge them in series no problem or look here http://www.powerscoots.co.uk/acatalog/24V_SLA_Battery_Chargers.html as they do some reasonable 24V chargers, a 1 amp charger would charge the pack in 5 hours the soneil chargers are great but cost a lot more.

The UK law of 250W is so stupid, most people find bikes to be disappointing at 250W you need 400W and up to start to feel anything, esp. in a hub motor, if you are ever in the area drop me a line as you are welcome to try a Puma powered bike, http://www.teamhybrid.co.uk sell the Puma motors and controllers and can do road legal through to off road mud spitting motor, what ever you like!

Good luck

Knoxie

 

[geoff57]

Hi all
twyfordbridge how much have you got to spend and how far do you want to go, we might be able to help you on what alternatives to sla you could afford. The NiMh packs Knoxie uses now and are also my choice, can be got hold of at resonable prices if you know where to look.

 

[safe]

The UK law of 250W is so stupid, most people find bikes to be disappointing at 250W you need 400W and up to start to feel anything, esp. in a hub motor

History is going to show that since America has signed an electric bike law that specifies 750 watts as the standard (rather than Europes 250 watts) that a whole new frontier of options will open up as a result.

America has always been the "last frontier" and we are again...

And we've even got our "outlaws" that scare old ladies with their overpowered, overvolted hub motors... it's what gives us the reputation as reckless cowboys. :wink:

 

[knoxie]

yes but you guys have to wait till you are 21 before you can drink, we can do it at 18!! :wink:

Nearly all of the UK kits I know for sale are illegal to the letter of the law as all the motors do produce more than 250W continuous.

750W is still too light for me, I need 1500 max! 8)

Cheers

Josey (the Outlaw)

 

[gardener]

Hello Twyfordbridge

If I'm not mistaken what you have there is a kit from electricbikesales.co.uk, if so, then you're right about performance being sad. I have their 350W kit but with that battery it's not much better. The battery is exactly the same as mine (though I have begun to suspect that
the 6.8Ah claim is being economical with the truth), and the controller looks the same too.

The good news is, thanks to the guys on this forum helping me in this thread http://endless-sphere.com/forums/viewtopic.php?t=1026 I have been running the kit at 36V. Performance is greatly improved. The kit will do 24-25mph on the flat, and can maintain 19-20mph up the sort of hills in my area (say 5-8% and mostly less than 200 yards long. Also the kit will actually accelerate up hills unlike when you run it at 24V. At 24V the kit is very much a pedal-assist bike, at 36V it becomes capable ebike. These speeds are with slick tires by the way.

The kit is further crippled by the lithium battery which really doesn't have the oomph. I bought a 24V 8Ah Nimh battery and charger from powacycle.co.uk for £140. This battery is far better though it weighs about 3.5Kg (against 1.5Kg for the li-ion you have) and is larger so you'll need a bigger trunk bag (or stick it in a side pannier low down for better weight distribution). You'll need to do something about the connector as the battery is for a powacycle bike. I followed advice from the pedelecs.co.uk forum (I'll post the link when I find it) and use a couple of American style plugs, one in each hole (-ve top hole, +ve middle hole on the powacycle battery) from maplin - about £2 each, but you could easily open the case and put whatever connector you want on it. I get more than 16.5 miles from mine which is my journey to work. It's still got some juice left after this but since I charge at work before making the return trip I don't know how much. At 24V Nimh the bike will cruise at 15-17mph without peddling and up to 18mph with a bit of help. My local hills cut it to 11-13mph. The Nimh at all times feels (and is) much more capable than the li-ion battery. The Nimh will slowly reduce in max speed as you run it down whereas the li-ion will go full pelt until it suddenly cuts out (probably prematurely when you go up a long hill)

As a temporary solution I'm running it at 36V using the 24V 8Ah Nimh wired in series with a 12V 7Ah SLA which I got for free from a UPS (Uninterruptible Power Supply) from an old computer at work. It's only good for 6 miles till the SLA gives up the ghost, but it's been useful to see the sort of performance 36V gives.

The controller heats up more at 36V but so far it's ok with the extra volts. You need to improve airflow to help keep it cool, it may get too hot in that bag. It's worth opening up the controller cover and check that the components are the same as mine, e.g. 50V capacitors, 60V MOSFETs to ensure you can put 36V through it.

I don't know what makes your kit 250W and mine 350W though. It may be something to do with the potentiometer setting on the controller. If you look at the controller there are two blue wires (and perhaps another one, I can't remember offhand) going to a little orange dial thing (it's probably covered in some shrinkwrap black insulating stuff which you'll have to cut off). This is a potentiometer which controls the speed the wheel turns at. I'm not sure exactly how it does this, whether by limiting current or voltage or limiting max motor revs. Anyway, if you turn it fully clockwise the bike will go faster. (Make a note of where it was set originally - mine was about the 1/2 way point). You may want to increase the setting incrementally to find the best setting for you. I just went to max and I've been fine but I haven't been running the li-ion very often. The reason is, it's my opinion that the li-ion battery is undersized for this kit and already struggles to put out enough power to be useful. Potentially the li-ion will suffer if you max out this setting. My li-ion suffered quite a lot from cutting out when going up hills for any length of time. Hills put the battery under stress and it gets chemically exhausted quite quickly. My advice to you is to buy a Nimh battery, or even SLA if you can put up with the extra weight and can charge them immediately after use (important or you'll damage them). You can then use the li-ion as an interesting paperweight / doorstop, or if you must, carry it as a spare range extender battery in case the Nimh runs out (not likely). My first li-ion battery from the shop shorted out internally and burnt a little bit though thankfully shut down the cell before turning into a raging inferno. This reminds me, DON'T LEAVE THAT LI-ION BATTERY CHARGING UNATTENDED! I was told my failed battery was a 1 in 10000 event but for me it was a 1 in 1 event (now 1 in 2 as I'm on the second battery...) I sent the first one back and the shop apparently sent it back to the manufaturer for tests (not heard back yet).

Your bike looks very neat, much more so than mine. Did you have to bend the frame to get the motor in? How many gears on your rear sprocket? I could only get a 5 speed on mine. If you do upgrade to 36V and heavier / more batteries then I think you'll need some better brakes as I don't think your current ones will be up to the job. I've just bought some shimano deore v brakes for £20 which are a vast improvement on my previous cheapo v-brakes which came with my £79 bike.

Paul

 

[twyfordbridge]

Hi Paul (and all you other helpful members)



I first looked at the Curry Electrodrive (after seeing my first knoxie video). I had to rule it out for 3 reasons.
1) My bike is only 18" frame and trinagular frame is probably too small.
2) It looked too much like an add on for my liking (no disrespect guys)
3) It is conspicuous and the local yobs round here would soon notice it and target it for theft.

I then looked at the 250 watt hub kits on the same site (Malborough based I think). These seemed good but were offered with SLA batts which I thought (at that time) would be too heavy.

I checked out ebay and ruled out all their off the shelf "baragains" as cheap and nasty with probably cheapo components.

Then I found another site. They seemed to offer virtually the same kit as the marlborough based website where knoxies videos were shown but with Li-ion instead of SLAs. Their site said they had upgraded the batteries to 6.8amphr from the previos 4.5 ahr at no extra charge. This would give speed of >15 mph and range of 22 miles supposedly.

I spoke with them on phone and by email (mostly about worries over poss fire risks etc). They p[ut my mind at rest. So I ordered the kit £400.

The battey pack was supposed to fit the saddle stem but was far too wide so I put it in an old wash/shaving kit bag and fitted it with removable velcro straps, no problem.

Thye controller was mounted in a black pastic box which was supposed to mount on the water bottle fittings on the bike frame. Problem was there were dozens of wires (only half of which were to be connected) hanging out the bottom which had to be taped up. That didnt seem too weather proof to me so I bought a cheap frame bag and put it all inside that. I was pleased with the look. But then tried it for performance.
I could not get anywhere near the quoted guide.
On the flat on motor only it would only reach 9.5 to 10 mph. Even with pedalling the battery seemed to be almost exhasted in about 11 miles.

Anyway, I have taken these photos of the label and of the controller.

I really wish that I had found this forum before having made a decision to buy.

 

[Ypedal]

Controller looks like a " YinYan " brand..

sticker says

24v controller
20.8v i assume is LVC ( Low voltage cut-off )
1-4v is the throttle Hall type
15A is the maximum amps

No, i don't read chinese.. lol.. but the numbers would relate.

 

[fechter]

Good transration.
That's what I would guess too.

The motor appears to be 200 watts.

 

[xyster]

As I suspected from your description of the kit's pitiful performance, the controller is 24 volts, 15 amps (360 watts).

From gardener's experience it sounds that, like many other 24 volt controllers and motors, these handle 36 volts just fine. That extra 50% voltage should increase your bike's top speed by 50% too -- from 10 mph to 15 mph it sounds like -- and with more hill-climbing power.

So...if this was my kit and I wanted to keep it, I'd return or sell those unusually pathetic lithium batteries and buy an 8-18 AH 36 volt NiMH pack.

 

[gardener]

Hello again

My kit is exactly the same. I bought it for pretty much exactly the same reasons + the light weight of the kit. The electricbikesales (EBS from now on) website even had the kit fitted to a marin (which I wanted it for) so I too went ahead and bought. If my kit is exactly the same as yours then I was suckered into paying £400 for the 350W when I could have got the 250W for £325 at the time.

I asked EBS about the battery and motor and they told me:
> The battery is made by Lishen and the motor by BMG. Both are well
respected Chinese specialist manufacturers. Lishen make batteries for IBM laptops and BMG motors for Boeing and Airbus.

I too couldn't fit the battery pack on the saddle stem. My controller cover would fit the water bottle holes either.

I don't believe the battery pack is 6.8Ah either. I opened mine up (due to seeing that the plastic cover had melted on one corner!) and while it looks well enough put together all the writing is in Chinese so that's no help.

All the extra wires are for things we don't have, like brakes that cut the power when pressed, pedelec sensors and so on. It's not a problem to have the wires but like you said you'll need to waterproof them / cut them back a bit.

9.5 to 10mph is pathetic. 11 miles sounds about right for the range though, but that's at 15-16mph and not at your speed. Check for the potentiometer (I'll post a pic later today) and see where it's set. I can make my bike as gutless as yours if I set it really low. Since you weigh only 10 stone you should get much better from this kit.

It is possible that your battery is failing. Get a multimeter and read the voltage across the terminals. After a full charge this should read approx 29V. Does it? Is the charger putting out 29.4V like it says it should? My first battery failed, whether due to the battery or charger I don't know. Be very careful if the battery is suspect, they can cause awful fires. This almost always happens during charging so please never leave it charging alone / anywhere you don't mind a large fire happening.

Check inside the controller too for the same components as mine to see if it'll run at 36V. Believe me, if you run it at 36V the kit is great. It is also much improved running 24V if you use Nimh - I can happily run around without peddling with that battery (except on hills of course - 24V will not get you up hills unaided). I suspect it was meant to be run at 36V but was downgraded to 24V to make it cheaper (and useless).

By the way, do all the lights on your throttle light up? Using only 24V only the min light comes on. At 36V they all come on and work as they should.

One of the EBS staff I spoke to didn't seem to have too much experience of bikes and told me a few untruths (out of sheer ignorance not malice though). The bit about CEM making them is nonsense as clearly the motors are Chinese, along with just about every other hub motor in the world.

Overall I think the motor and controller are pretty good, but are let down badly by the rubbish battery. Overall I have so far spent about £700 getting this kit to work well (and still need to buy a 36V Nimh and charger which will be approx £250) When all is said and done I would have been better to buy an Eeze Torq or similar and had a lot less hassle, but that would have been no fun.

To make the kit useful you're going to have to invest in better batteries I'm afraid.

Paul :lol:

 

[twyfordbridge]

Hi again,
Thanks for your prompt replies. I dont know whether to laugh or cry.
I will answereach reply separately.

Cheers Ypedal, the sound of a "Yin Yan" controller really inspires confidence.

Fechter, if you're right about the motor being 200 watt, does this mean I cannot upgrade the battery to 36v ?

Xyster, Although I am quite peed off with my purchase,I think I am stuck with it. However, if it could be made to give performance like gardener has got, then I'd be more than happy to stick with it.

Gardener, Thanksfor your post. I am keping my fingers crossed that we have got the same kit - at least your project has shown that all is not lost.
Is there anway that we can be sure we have the same bits in the kit? EBS say n their site that the motor is 250 watt. I dont suppose there is still a little sticker on your hub?

Also, does the controller look the same as mine? - I would hate to try and upgrade to 36v if something in the setup is not up to it and it all goes up in smoke!
My controller wouldnt fit bottle holder - holes drilled at wrong spacing.

What the hells a potenti-thingy ?????

Battery reads charging slowly in inrcrements only up to 26.2 then the red light changes to green and the battery (while still connected to charger) reads 29.3. Even leaving it at the this 29.3, the battery will only read 26.2-3 when disconnecting from charger.

I will open up the controller and check it against your pictures (hope it goes back together again!!)

Re the throttle lights: There are 3 on mine - Power, Full and Empty. Power and Full show most of the time but after only a few minutes use the Empty light comes on when I push the beast to its 10mph limit. Drop the throttle to about 8 or 9 mph and the empty light goes out. (I will have to try this with the voltmenter fitted to see at what stage its happening)

Right now, one of my main concerns is that it appears the controller may be up to taking the extra 12 volts - but what about the motor itself. I did notice that the larger three power wires from the controller were noticeably far heavier than the wires they connect to on the hub. But then again, I know nothing about electronics. (I have been reading other members analogies of water tanks pipes and water flow - its kept me awake at night for hours afraid to drop off in case I wet the bed with all that water!!)

Anyway Thank you all again for your help so far - please please stick around.

 

[knoxie]

Hello Twfordbridge!

Dont worry!! your controller can be replaced very cheaply for a better one should it go wrong and your motor would most likely take 600W without overheating, there is no difference 250-350W, those little motors can take a lot more.

Does your throttle have any led indication? you may have to be careful over volting it if it does as they sense the battery volts, it sounds like you should be ok as the other poster has done it already.

I cant see why 600W would be easily within the scope of those little motors.

Cheers

Knoxie

 

[gardener]

Hi again,
Gardener, Thanksfor your post. I am keping my fingers crossed that we have got the same kit - at least your project has shown that all is not lost.
Is there anway that we can be sure we have the same bits in the kit? EBS say n their site that the motor is 250 watt. I dont suppose there is still a little sticker on your hub?

Also, does the controller look the same as mine? - I would hate to try and upgrade to 36v if something in the setup is not up to it and it all goes up in smoke!
My controller wouldnt fit bottle holder - holes drilled at wrong spacing.

It looks exactly like mine.

What the hells a potenti-thingy ?????

The one on my controller looks like a little dial mounted on a square block. It's about 5mm square and should be on the end of two blue wires coming out of your controller. It's probably taped up to stop people fiddling with it. I'll take a picture when I get home.

Battery reads charging slowly in inrcrements only up to 26.2 then the red light changes to green and the battery (while still connected to charger) reads 29.3. Even leaving it at the this 29.3, the battery will only read 26.2-3 when disconnecting from charger.

Hmm. My first battery always read 29V after charging (when disconnected from the charger). The one I have now started out at 29V and after about 20 cycles has settled at 28.4V. I get 29.2-29.3V when connected. I think your battery is not healthy. Perhaps one of the 7 cells is not accepting charge. Have you tried getting a refund / replacement on the battery under warranty?

Re the throttle lights: There are 3 on mine - Power, Full and Empty. Power and Full show most of the time but after only a few minutes use the Empty light comes on when I push the beast to its 10mph limit. Drop the throttle to about 8 or 9 mph and the empty light goes out. (I will have to try this with the voltmenter fitted to see at what stage its happening)

Well done on getting all the lights at 24V

Right now, one of my main concerns is that it appears the controller may be up to taking the extra 12 volts - but what about the motor itself. I did notice that the larger three power wires from the controller were noticeably far heavier than the wires they connect to on the hub. But then again, I know nothing about electronics. (I have been reading other members analogies of water tanks pipes and water flow - its kept me awake at night for hours afraid to drop off in case I wet the bed with all that water!!)

I reckon the motor will be fine. Does it get hot after a 11 mile thrashing at 10mph? (If you have the patience to perform such an awesome task, do it at night so you don't attract shouts of "Do you want a push?" ). :lol: :lol:
My motor never got warm at 24V and only gets a tiny, tiny bit warm at 36V.

 

[xyster]

Battery reads charging slowly in inrcrements only up to 26.2 then the red light changes to green and the battery (while still connected to charger) reads 29.3. Even leaving it at the this 29.3, the battery will only read 26.2-3 when disconnecting from charger.

Sounds like there's a serious problem with your battery pack. The 29.3 volt reading while plugged in suggests the pack is 7 lithium cells in series (which at 4.2 volts per cell full charge would = 29.4 peak volts). 26.2 volts hot off the charger means each cell is around 3.74 volts (26.2 volts / 7 cells) -- a point where there's only 20% charge left! If this is correct, I'm surprised you even get 10 miles -- perhaps that's with a lot of pedaling.

 

[gardener]

Battery reads charging slowly in inrcrements only up to 26.2 then the red light changes to green and the battery (while still connected to charger) reads 29.3. Even leaving it at the this 29.3, the battery will only read 26.2-3 when disconnecting from charger.

Sounds like there's a serious problem with your battery pack. The 29.3 volt reading while plugged in suggests the pack is 7 lithium cells in series (which at 4.2 volts per cell full charge would = 29.4 peak volts). 26.2 volts hot off the charger means each cell is around 3.74 volts (26.2 volts / 7 cells) -- a point where there's only 20% charge left! If this is correct, I'm surprised you even get 10 miles -- perhaps that's with a lot of pedaling.

Yes Xyster there are 7 cells in series as you thought. It really looks like the battery is not accepting charge. I find that whenever my one is exhausted it reads about 26V (can't remember exactly) but it's in that ballpark.

If you can get it replaced under warranty that's great, but to be honest the battery isn't much good even when it works

 

[twyfordbridge]

Hi again,

I must make this quick as the washing up is still on the side and my wifes due home from work in 15 mins...... much more scary that an electric bike problem !

Okay - thanks to you all. It seems the underlying problem may have been that the battery was knackered from the start. The kit is only a few weeks old so well within warranty. I have cut & pasted all relevant comments regarding the battery charging and will email these to the supplier and ask for a replacement under warranty.

Meanwhile, I accept everthing you say about 36v NiMh being a better option and I will make enquiries about the cost of these and charger. If I can afford it I will buy these and keep the (hopefully) replaced 24 Li-ion as
a get me home spare (which was the topic of my intial posting).

Thanks again guys, I'm off to get my rubber gloves to tackle that washing up (4 mins till she gets home now)

I will keep you updated. Cheers, Richard.