chazpope

This is the review I read and it is the same bike that I tried, only it does not work ? So is Granite now obsolete ? I then better not buy it The regenerative braking is a new feature on the 2010 Granite and Diamond models. This is activated by pedaling backward, be prepared when you use it. It's designed to slow you down and that's exactly what it does. No matter how fast you're going it'll take you down to a crawl in roughly 2 seconds. It's a handy feature and no doubt it will become my primary brake.

Hi, I am thinking of buying a Granite on a cycle-to-work' scheme, I tried one and was happy with the performance - 2 year warranty on the battery is also quite good. I was quite keen to try the feature where 'if you pedal twice backwards while going downhill it uses the motor to slow you down' - I read about this in 2 reviews. However I found that this does not work - does it work for you ? Also I wonder if these bikes can be de-restricted for off-road use? Thank you

Thanks, This charger looks good but doesn't seem to have input for the thermo couple ? so it will not take into account the T and dT/dt like the other chargers do. I guess it will charge faster but I only charge overnight anyway so for me it does not matter. I've been using the bike with my diy charger - no problem other than that it is inconvenient. I really want to get my Shenzen charger to charge this. I asked the chinese co that makes the other one for advice and got zilch, now I will try to as the Shenzen co what it means when it blinks red/green but I don't think I will get an answer.

in the meantime I built a 1 amp dumb charger and charged the battery through the charging socket while monitoring current and thermistor resistance. that went from 18K cold to 6K when moderately warm after 10h of charging. The battery was charged and took me to work today with very little voltage drop - still to cycle home but looks like the battery itself is working ok. Now I won't recharge with this charger until empty cause it would not know when to stop - so I need to sort this out to use a proper charger that can top up from half empty

yes I soldered 10K resistor onto charger plug wires and then connected the charger to the bottom of the battery (so that its thermistor does not play). I will try the other charger in a similar fashion over the weekend. I think what is happening is that as soon as that charger starts its cycle it does some assessment of the battery behaviour (it can only be voltage at a certain current) and it decides that the battery is faulty. and it has a different blinking mode (green/red as opposed to only red) to indicate that. I will try contacting the maker for more info. I would also like to fix the broken HP charger but not sure if possible - a new one costs over 40 quid

Yes like I said just above I soldered a 10K resistor between ground and ntc wire - and tried it - no change. There is no voltage - light is blinking, then I connect ground and red to battery and click-relay goes and light goes off, disconnect - blinks again. BTW this charger normally flashes when not connected and glows solid red when charging. I repeated this test again, same result. Now the thermistor measures 13.7K (not 10K) but then this simply corresponds to a temp of 16C so the charge should still start I reckon

1. there is no voltage at all - as soon as switched on I hear the relay is clicking inside and nothing comes out - the red light blinks at 2Hz . As soon as connected to battery the light frecuency increases and it fades out. I tried connecting a 10K resistor between the - and ntc wires - it made no difference. I suspect this charger is faulty but it still shows some reflexes 2. yes it is installed inside the battery - but is shows 14K (not 10K) at room temperature! I wonder if this is the problem and makes it not charge I guess I should try the working charger with 10k resistor but that is not as easy so will do it on the weekend.

The original pack came with this charger HP1202N2 It charged the battery once for about 3-4 hours and died? before a full charge (green) was reached. Now there is a possibility that the two packs (and chargers) had incompatible NTC thingies - one is '10K&B=3050' the other is 'IS103AT(10K)' what do you think ?

hi yes this is the charger I have - (though mine is from 2008) it flashes green and red and I already know it means 'error' the question is - what error. This is a constant current charger and it should work even if you take out (say short) or even add another cell. There is something it does not like at start up and that's that - I know they go through some pulse to start. also this thermo couple I had came from another battery-charger combination but I thought it should not make a difference I have tried chinese companies for support before and got a robot translation answers over and over again - but who knows this one may be different.

I have made a new 10AH NiMh battery but none of my two chargers would charge it - perhaps it responds differently and the chargers just would not start the charging cycle. I would like to buy and try another one say that does something like 3A - but can't seem to find one. All I found on ebay was for Lead acid or Lithium battery or the type was not specified and when I asked does it work for NiMh I got a negative answer Any ideas ? In another thread I am looking for an answer why my chargers would not charge the new battery (it did once but now just flashes green and red) - but that has not produced any result so far. I guess I could try building a charger - but I would rather buy one

I doubt it, after I did this the pack got charged to almost full and then delivered that power ok and there was no sign of any damage. I don't see anything wrong with discharging with bulb or whatever now and then as long as there is no reverse voltage situation. On a power drill nothing monitors the discharge state voltage but still they work multiple times before they go bad. The pack is still capable of delivering 5 amps through that bulb as it was not discharged completely, also I measured individial voltages undert load and they are the same, also the charger should work (charge with a regulated 1.8A) whether or not a cell or two are there or not. I even tried adding another cell in series and it still did not start charging, so it is a bit of mystery at the moment - and the key is in what it meanswhen the ShenZhen ABT charger blinks green and red ...

no replies, I guess I should buy another charger ant try that - any recommendations ?

Hi It appears that the charger decides not to charge this battery I just recelled my Powacycle Cambridge battery (this is my third time) with Tenergy D size 10000mah cells - looks like they are the best available at the moment. After I built the battery the cells were almost empty so I discharged them with a bulb, checked that they are all the same and started charging. The charger showed the red light as usual -and charged for about 4 hours - but after this the charger light went off (rather than turn green as normal). If I connect it again it starts blinking faster and then there is no light and it is not charging. What this charger usually does is blink red with no battery, then go red to charge and green when ready. I am not sure what a dying-blinking light means but looks like when I connect the battery it decides not to charge it. The battery itself was charged ok this once and I put it on the bike and it performed greatly until it went flat - capacity was more than I expected. But now I have a flat battery and no way to charge it ! I actually have 2 chargers and batterries - I tried the other charger - it normally shows green with no load - then red and finally green when ready. But it one does not seem to charge the new battery either and shows a blinking green-to-red light. Again I have no idea what this means ? I opened the battery and could not find anything wrong. The thermo thing measures about 14K - same as the other battery, fuses are all there. Comparing how the chargers charge the other battery the difference is that there the voltage goes up to say 27V at the start of charging (when the charger seems to be pulsing) whereas on the new one it seems to stay at 24.5 volts - I wonder is it that the new bigger capacity makes it think there is a short so it does not start. But then again initially I had no problem and charged ok for 4 hours Any ideas ?

I have re-celled Powacycle Cambridge twice First time it cost me £69 for 20 hybrid cells form maplins - see thread - this was some time ago and more than 1000 recharges later this battery is still usable Right now I am re-celling with 10Ah Tenergy that cost me £130 (incl VAT and customs) from the US - tried it today - works great. You need 20 D cells (can't fit more in the case) Do not just buy any cells from Hong-Kong - mostly they do not work, I got some off ebay and had to ask for refund which was tricky.

And where are they now ? What I did was charge and test them individually on my Lacrosse charger at 1.8 A (same as bike) and compare with the old cells I was replacing. I found the 'new' ones were way way below on performance - about 3Ah capacity at a considerable lower voltage (for the 'best' in the pack). So much for manuf claims of 10Ah and 30Amp currents. I guess after seeing that their weight was about half the weight of similar cells I should have known not to buy them. But I had my money back in the end - no complaint there. Question now is - where do I get 'good ones' from ?

believe me I would not chuck 50 quid's worth of cella just like that I was wishfully thinking about 'money back option' I have fiddled a bit more and yes there are maybe 5 in the pack that behave differently. During charging these show a higher voltage (by about 0.15V) than 'healthy' cells. This I guess causes the charger to reach 33.0V and cut off prematurely after about 1.5h. Then, during discharge - these cell seem to hold much less charge and get depleted very quickly. I will try talking to shop about this - see where I will get.

Ok so these nicely done heat-shrunk battery packs - I broke them up to investigate cell by cell. To start with - with the temperature probe not touching the cells the charger still switches off (turns green) - probably because it is voltage drop sensing. This happens after about 2 hours anyway, thereafter by 10 mins so it's not timed. So I cannot force a full charge even if I wanted to. Second - after the 2 hour charging if I apply a 4.5 Amp load (.45C) - after 10 mins some (3-4) cells lose all voltage and go into reverse. Also initially some cells did get hot while charging. I discharged them idividually and they do not go hot anymore. Not sure what to do next - I can't charge cells one by one to test and they won't charge for long enough as a whole, also some cells seem to be *****d. I suppose I can try chaging them with my lacrosse charger with some contraption, not sure if it goes as far as 10ah though. Should I buy some more or try to reject the whole lot - (this may be impossible - Hong Kong) I must say I had none of this crap with the maplins cells - 3 years ago I just put them in and now after 1000 charges they still work as 80% new. I want to find a solution though as there is no other option

for now without breaking up the battery I found that : - charger charges with a constant 1.8 A - 4 groups of 5 batteries behave consistently voltage-wise during chraging - after just under 2h the whole battery heats up a little and charging stops so it behaves like a smaller battery - I will do more tests tonight. question remains why it would not maintain voltage under load even when full, it kind of drops to 22 v very quickly and I haven't yet found out is it one cell doing it or all. Is there such a thing as 'current rating' i.e where it only delivers up to x current ? If you discharge a fresh cell at say 0.5C - what should the voltage be

I see - Click here to see it - you must have seen another version

Shouldn't it be charging for 5h at least ? I use the powacycle charger - it is rated at 1.8A - so for 10Ah it shouldn't be as short as 2h I will do some of these tests tonight, it's not going to be easy cause you can't just measure voltages when the cells are packed in a metal tube. I think the first thing I will do is separate the thermistor from the battery and see what happens

so what can I do now - how do I ballance the cells ? these were new cells they should have been the same I did measure the voltage of the 4 x 5 packs before connecting them it was the same within 1% it is a powacycle cambridge, I am sure the thermistor works as when the battery is hot the crarger flashes as it should. does it cutoff just by temperature - I would have thought it monitors the voltage drop too

no idea about 'balance' - does NiMh need any ? I have 2 chargers of slightly different design and as far as I can see they only have a temperature probe and that's that.

Hi I re-celled my 24V NiMh battery with 20 of these 10000mAh cells - (someone here found them on ebay) However the new battery won't work on the bike - it shows full voltage but when I turn the motor on the voltage drops immediately so you get a flutter effect and it's not usable. When discharged with a car bulb (5 A) it goes down to below 20V in just about 10 minutes, also when charging (< 2A accoriding to charger) it takes only about 2h to cut off - so I get about 1Ah (not 10Ah) from it. I repeated the discharge/charge exercise twice and it made no difference. Any ideas ? p.s. I have done this before and that battery still works very well - but I used cells from maplins

excellent, thanks!

Hi my battery is due fror another rebuild and I wonder if anyone can point to a cheap source of D size NiMhs ? I need 20 - so I am looking to do it for < 100 Thanks tried to post this is Technical but it woud not letme, not sure why