Fecn

I replaced the Nexus7 hub gears with a Nuvinci CVT instead... 350% range instead of the old 244%. I have a 21tooth cog on the Nuvinci as I cared far more about hill climbing than top speed. I did try an 11tooth sprocket for a while which gave a top end assist speed of around 24mph but I changed back after a few weeks as it was very detremental to hill clikmbing.

Succombs Hill.... no problem I wasn't fast up there, but at least I wasn't sweating either. My agattu really can climb any hill.. albeit at 4.5mph... With my modified gearing, cruising speed on the flat is a healthy 17.5mph. You do need to pedal though as walk-along throttle has very limited power and speed available to it.

My personal choice for data logger was the Raczing Wilog. I liked that it used my mobile phone for displaying all the data as I already had that attached to the handlebars on my bike. It meant I could get the wilog installed very neatly next to the battery and still see how much current I was pulling as I was riding along. http://www.pedelecs.co.uk/forum/electric-bicycles/4821-watts-up-vs-turnigy-power-meter-analyser-2.html?highlight=raczing#post62559 All the graphs I post on this forum are thanks to that widget... I wrote some scripts in python for processing the .log files it saves off into csv for importing into spreadsheets.

The most often quoted figure for average power usage in real-world conditions is around 10watt-hours per mile. From my own long distance rides, that seems about right (30 miles from a 260Watt-hour battery). I've done some big big hill climbs on a 'derestricted' bike (~450W average motor power) and found that it used around 17.5 Watt-hours per mile. For full-throttle use... well.. totally depends on the motor, top speed etc.... If your motor was using 250W of power and to attain a top speed of 20mph, then you'd be using 250Watt-hours per 20 miles, which would give you 12.5watt-hours per mile. 40watt-hours per mile sounds like far too much.... unless you had a 1KW motor or something like that.

Hi Tilson. I'm pretty much certain that it doesn't just use voltage alone. The battery meter seems to be measuring watt-hours rather than voltage (certinaly for most of it's range). The final cutout I would expect to be based on voltage though.

The BMS protects the battery. On my 20Ah Ping pack, the BMS has a 40A current limit set. The Fuse would be to protect your wiring (which in my case is only good for 30A)

25.9v is the 'nominal' voltage of the pack... which is the voltage it reaches when 90% of the capacity is used up. The voltage drops off very rapidly after that. I've recorded all the charge cycles for my battery since new, so I know for certain that the slow flashing light starts pretty much exactly at 10% remaining charge, which would be... at 25.9v rather conveniently. I'd guess that the fast flashing light starts at around 5% remaining or around 24V, but that's only a guess as I don't spend much time staring at the battery meter when riding along. Taking the pack below 21v would be damaging to the pack and prevent it from recharging fully which is why the cutoff happens at ~22.5v. I'm a contender for the 38.5mph club myself... I've always bottled it any faster than that and hit the brakes.

I was doing a conditioning run on one of my batteries a couple of weeks ago. It just so happens that I had a datalogger attached when I did it. I found the dropoff of power once the battery goes below 26v to be very noticable. Just before the final cutout happens at around 22v, the system is providing a measley 150W of peak assistance. http://yourhome.org.uk/gallery2/d/3897-2/Flatbattery.jpg The new 15Ah panasonic battery was mentioned on the BikeTech X-Series thread.... Here... http://www.pedelecs.co.uk/forum/electric-bicycles/5323-panasonic-300w-15ah-suspension-moutain-bike-photos.html?highlight=biketech

Thanks Alex - I'll give them a call in the morning. Edit: Just an update to the thread in case anyone cares.... The problem was indeed a faulty controller. I installed the replacement (took about an hour) and it worked first time. Powacycle's spares department were very responsive and shipped me a controller for the next day. It cost £55 (plus postage) to get the bike back on the road again.

I ordered my Ping 29.7v, 20Ah pack directly from Ping via his website. It was cheaper than ebay and besides which, I don't have an ebay account anyway. No problems with the service. Ping gave excellent customer service.

Can anoyone tell me where to order spares for a Powacycle Windsor? Strider has dropped the faulty windsor discussed earlier in this thread round to me for fixing. Having examined it, my conclusion is that it's either the controller, or the hall sensors in the motor so I'd like to order a suitable controller (and hopefully a not too expensive one) to pop in as a replacement and see if that sorts things out. Cheers, Jim

Yes - the motor controller (regulator) will most likely be responsible for determining the cutoff voltage, although many BMSes also have a cutoff voltage built in. It would probably be very unwise to try a 36v pack on your 24v(29.4v) controller though as it is likely that it has 35v rated components in it.

You may find a 24v (26.4v) ping pack to be disappointing if you're used to a 25.9v lithium-ion pack. The LiIon pack will deliver most of it's useful energy from 29.4v when it's fresh-off-the-charger, down to 24v when the battery is empty, whereas an 8-cell ping pack will deliver from 27v when fresh down to 22v when empty. This means that your bike may reach it's cutout voltage whilst the ping pack is still at 30% remaining. I initially bought myself a 24v 8-cell ping pack and found it disappointing, so I ordered some extra cells and a new BMS from Ping and converted it to a 9-cell 29.7v pack which matches the voltage ranges of Li-Ion more closely. Ping will make up custom packs upon request so there's no problem getting a 9-cell pack if you want it.

I love the Cruiser, but hate marmite. Aiden - Do you have a bigger pic of the cruiser you can post please?

Yep - the inverter is a far better option. That way you can always start the car's engine and burn some fossil fuel to get extra watt-hours.