[ATTACH=full]15307[/ATTACH]

http://www.roswheel.eu/roswheel-shop/all-items/top-tube-double-phone-bag

 

Now how much lipo can I fit in there...

Probably not as much as you think. I bought one ages ago with a mind to fit 2x 6S 20C packs either side, but it would only take one (published dimensions don't take into account the wedge shape). Undeterred, I cut the phone holder out and sewed on a couple of small camera bags instead. You might have a bit more luck with Multistar packs though.

Edited September 1, 20169 yr by danielrlee

Thinking about a small 8 Ah pack for every day use. And as a range extender for getting home when the main pack runs out.

Big Fine Battery

 

 

I now have a 20 Ah battery composed of two different types of Hobby King Lipo packs (same size, same cell count). The Multistars are out of stock for months now so I went for Graphene on sale. Bigger, heavier but not by much. I was really scared that I wouldn't be able to solder the XT60s on because the wire is so thick. In fact it is 10 AWG on the inside of much thicker insulation than the Multistar I only just managed to coax the gray insulation cap over the wire. Above are the 4S wired up in parallel with my new lip alarms.

 

Road test

 

So I charged up to 41 V (5 hours in all) and set off on a road test. 48 km in 1 hour 48 minutes. That used 8.364 Ah at 6.79 Wh/km which I estimate is about half the useful capacity of the battery. Happy bunny!

 

 

I love this bike! It does need a suspension seat post, several km of gravel road down the valley to Bera convinced me of that! It breezed up the pass at Ibardin (the big bump above) at 18-20 km/h average in second and a couple of hairpin bends in 1st. I did manage to conk it out on a ramp over 15% up to the top Venta at Ibardin, bottom gear not low enough.

Gearbox update:

 

The owner of the LBC said my little slope that I couldn't climb is over 20%!

 

In any case I now have an 11-32 cassette I know, doesn't exist, you didn't think I was going to mount the 12 and give up on my cheap downhill thrills did you?

 

So I went out and tested on my local 1 km 15% test hill. I had to work hard but didn't draw more that 300W all the way to the top. The cassette is better than the 11-28, 3rd is a very comfortable slow speed around town gear. Second is 26 so a couple of teeth more than my previous 2nd gear and will climb most normal hills (my normal is bits at 12%).

 

If you are thinking of getting a GSM the ideal cassette on a 28" - 700C wheel bike is an 8 speed 11-34 if you are reasonably fit. 11-32 would probably be the best bet on a 26" wheel but I haven't crunched the numbers. If you are less fit you don't need a high top gear so a 7 speed 13-34 hyperglide would do the trick.

Edited September 18, 20169 yr by anotherkiwi

I am surprised that the torque immitation controller is not more popular.

 

Torque imitation means current control. All that blurb about huge pedalling database is just made-up sh!te. I have a logger that shows that for each level, you get a fixed current (or watts - same thing). These controllers have been around for a while now and are more or less universal in kits and they're installed in many OEM bikes.

 

Current control is more or less essential for crank-drive bikes for obvious reasons.

 

IMHO, these current control controller with a simple on/off cadence sensor give a more than adequate riding experience for normal general purpose riding. I wouldn't want anything else. A torque sensor is only necessary if you want to do difficult off-road riding where you need a more sensitive power response. OEM systems, like Bosch, use torque and cadence sensors, and we're starting to see over-rides of the torque sensor for easier hill climbing, like on the Kalkhoff "Climb assist". A torque sensor on it's own for general purpose riding would be worse than a cadence one.

This one is so different from the other two controllers I have. The ramping up and down of the current is so smooth. The initial supply of power is strong but once at speed very gradual. It also seems to go beyond the current limit, I think this is due to the C14 setting of 3 "Stronger assist strength of motor"?

 

If only it was 36/48V, now that I can do 12S...

While mucking about on bike-discount.de of course I had to discover the CS-HG50 13-34... I'll try my 11-32 as soon as the weather permits but now I know I can make an 11-34 in 7 speed. 11-15-17-20-24-29-34

 

http://www.bike-discount.de/en/buy/shimano-7-speed-cassette-cs-hg50-13-34-535334/wg_id-8169

http://www.bike-discount.de/en/buy/shimano-sprocket-11-t-with-spacer-ring-for-cs-m771-bj-bk-162015

http://www.bike-discount.de/en/buy/shimano-distance-ring-pu-3mm-for-7-speed-cassettes-37437/wg_id-8175

New Lipo charger arrives

 

And first Lipo charging incident ensues...

 

No! No white smoke, no projection of flames, no fried fingers. Sorry no real drama. A burning plastic smell told me something was amiss and the 10 year old converted PC power supply promptly made a "pop" sound and ceased to function.

 

Maybe my drawing 18 Amps constant was a little beyond its means?

 

It did charge the two 4S packs to 16.6 V from storage voltage at 1C (10 Amps) in just over 35 minutes. It did bravely manage to provide 9.6 Amps for a short while on the 6S packs.

 

So it looks like tomorrows long ride is cancelled "due to unforeseen circumstances" A new power supply is on order.

 

Tony's top tip:

 

A 300 W charger really does need a 30 Amp power supply to charge 6S at 10 Amps...

Power supply autopsy:

 

A condenser (? composant which looked like a brown chewing gum rather than a tiny coke can) has failed, spewing grey goop (is that word copyright free now Gwyneth?). I had bet on a capacitor failing so I lost that bet... <pays self 1€>

 

I have chosen to go with an R/C 540 W 30 Amp power supply. I may buy a 20€ PC power supply as a backup. My choice was motivated by two 15 Amp x 18 V outputs from which I will be drawing just over 12 Amps each.

 

Of course charging the 4S Multistar pack to 4.15 V per cell was always going to be a test of iffy cell number three. Test failed... The cell is losing voltage by the hour. When I get back from shopping later I will put it in discharge on the Battery Medic just to keep it safe. It charged to 4 V and behaved itself for the last several charges. It has held storage voltage for weeks on end. Just doesn't like full charge. Looks like a replacement 4S pack is on the budget for next month... Cost per month of broken one: 4.65€ or 0.05€ per kilometre (estimated)

 

The good news is that charging time for the whole 20 Ah battery will be about an hour from storage voltage to full capacity, two hours from empty. That is a breakfast time charge, or out on the road, a lunch break (hey I'm European - two hours is normal lunch!) charge.

New member here, been reading lots but this is my first post!

 

I admire your determination anotherkiwi to use RC packs instead of a regular eBike pack, I decided I wanted the plug and play simplicity of a Li-On battery with a built in BMS when I decided to order my conversion kit.

 

In my RC hobby I have recently modded a Server Power supply for charging car RC packs. Follow this link:

 

http://www.rchelination.com/setting-hp-dps-1200fb-power-supply/

 

and you too can make a very small 100A 12 v supply (yes, 100 amps!) or even stack two together for 24v at 100A.

I now have a VERY BIG (zut won't fit in the battery box...*) RC power supply which is finishing a 10 Ah Graphene pack as I type. Charging at 1C the Multistar packs puff ever so slightly, the Graphene packs don't. 35 min from storage to full voltage (4.15 V per cell) on the Multistar and 31 min for the Graphene. So they are different.

 

The choice of lipo was first of all one of cost - I have been running a 10 Ah pack since March and it only cost me 180€ with the charger and all the wires and bits you need.

 

Then I discovered the lack of voltage sag - most of my rides have slopes of up to and over 12%. My entry level Li-ion bottle battery doesn't like that and a replacement Li-ion battery that has enough power to handle the hills is eye wateringly expensive. Or from China, but I prefer a good old European consumer protection guarantee when I buy stuff that costs over 200€.

 

Third I go places where there is no mains electricity. There is a solar panel and a 12 V battery I can hook an R/C charger up to however.

 

Fourth seeing how my >260€ Li-ion battery is behaving after about 3400 km I don't mind the idea of getting 100-150 charge cycles from Lipo then recycling. It is going to be more cost effective on a per kilometre basis. Swapping out a 27€ 4S pack that is showing weakness after 6 months use is not bringing a tear to my eye.

 

* The power supply, two 300 W chargers and 20 Ah of Lipo do fit in the battery box but not in the way I would like them to fit

A what if? ride

 

So my 20Ah battery was all charged up to 41.5 V time to try something new. I did my usual station run but left the assistance set to 5 all the way and tried not to pedal too hard. Kept the right cadence of about 70 and used the gears properly.

 

Result 8.5 Wh per kilometer. Cool as a cucumber and not tired at all. So it does work OK as a means of transport this electrical bicycle thingy! I'll go back to being my normal push hard on the pedals self next time out. The difference in power use between the two riding styles is about 2 Wh per kilometer. The difference in range (80% battery use) is 21 km.

 

My iffy cell stopped misbehaving and stopped dropping volts at 4.1 V so it was 0.05 V lower than the others.

 

The Graphene pack cells are within 0.01 V of each other whereas the Multi stars are within 0.03 V.

 

That is all of the (I hope) useful data of the day.

Interesting how close to the often quoted 7.5wh/k (12wh/m) you are.

 

8.5 wh/k when being lazy, 6.5 when putting effort in, neatly straddling the average. (in imperial the numbers are 13.7 wh/m and 10.5)

 

 

 

Sent from my HTC 10 using Tapatalk

I'm feeling more "normal" than last year when I was learning the ropes and really giving it some welly I was down around 5.7 - 5.8 Wh per km once I got fit. flecc said I didn't even need a pedelec! But then there are those hills...

 

I think during a normal ride when I am really needing the motor most times I am using over 10 Wh going up and of course 0 Wh coming down, the average of 6.78 Wh the other day resulting from the not so flat bits where the motor helps a little bit. On the gravel section I was at 23 km/h average in assistance level 3 so drawing about 90-115 W especially when stop/starting through the bits with flood damage.

Floods??? You have floods? I thought you said the sun always shone?

Just teezing.

Do you think those Wh averages would be approx. the same for a hub?

The last time that river flooded it was on the 8 o'clock news, several villages were badly hit. Thunderstorms on mountains after hot sunny periods = flash floods. Today it was >30°C

 

Yes. Probably a wee bit lower Wh average with a hub but that is down to my riding style.

I love lipo!

 

OK I may have said that a couple of times... The Graphene packs may be more expensive and slightly bulkier but:

 

They charge faster

They stay balanced

Cells are within 0.01V

They don't puff. At all! Charge or discharge.

 

I will have to try a run with them in series to see how much they deliver between 4.15 V and 3.65 V. I am guessing much more than 8600 mAh I got from the Multistars, maybe 9000 mAh? I am also happy with my new charging setup: 2 x 300 W is just right for 10000 mAh packs and the power supply is working great now that I know what it wants (18 V output). The packs charge in minutes not hours at 1C, all 4 packs charged to storage voltage in less than an hour total after today's ride.

 

Today 61.54 km, average speed 23.67 km/h, top speed 59.19 km/h, elevation gain 1259 metres (eat your heart out Eddie ) max altitude 455 m. For a total of 467 Wh or 7.59 Wh/km. There were a couple of spots over 13% in the hairpins. The lycras love it. They don't like me much... Oh and I spotted a lad on a Haibike, of course he wasn't wearing a helmet nor full body armour, just shades. Was he dongled?

 

 

No photos a google image search gives a good idea, just that the sun was setting when I reached the top and I almost whipped out the nikon but I'm a rider not a photographer

Edited September 27, 20169 yr by anotherkiwi

A burning plastic smell told me something was amiss and the 10 year old converted PC power supply promptly made a "pop" sound and ceased to function.

 

Maybe my drawing 18 Amps constant was a little beyond its means?

 

Capacitors don't see current. Instead, they see voltage. There's only two reasons that I know why they blow: Voltage too high compared with the voltage written on the capacitor, like if you connected a 12v power supply directly to a 6S battery pack; or reverse connection. I'd check again whether you have your connections the right way round!

 

There's a fair chance that it'll come back to life if you put in a new capacitor, unless you didn't make any of the above errors.

It wasn't a capacitor I said condenser because I tried to see what it was on wikipedia, apparently I failed. It was a composant that looks like an old school chewing gum or a "berlingot". Bottom row, center right. Caps are top left.

 

http://previews.123rf.com/images/vilax/vilax0912/vilax091200018/6074328-Composants-lectroniques-et-des-pi-ces-d-tach-es-r-sistances-condensateurs-diodes-transformateurs-tra-Banque-d'images.jpg

 

I know yellow = +12V and black = Gnd it was connected correctly and it was load that it couldn't handle. It still turned on and spun the cooling fan, just didn't provide enough power to the charger any more.

 

A ten year old free PC power supply that can't provide 18 Amps constant has no place in my life, it has been binned.

A capacitor and condensor are the same thing, except nobody calls them condensors these days, though occasionally you here the capacitor on the old automotive ignition systems with contact breakers called a condensor.

 

The ones in your picture look like tantalum capacitors. They're standing on the symbol for an LED. They're polarised, so would pop if subjected to reverse voltage. I've never actually seen one pop, but I've heard that they catch fire. Electrolytic capacitors pop and give off pungent smoke when they blow, and they spread gunge all around. They're the ones top left of your picture. They also can't take reverse polarity without blowing.

 

No current ever flows through a capacitor. It only flows in and out with massive current, which is what causes the spark when you connect your controller to a live battery. The whole point of capacitors is that they charge and discharge instantly with high current. They boost the instantaneous current in things like PWM chargers and motor controllers. They're also used for smoothing out current by absorbing peaks and giving back in the troughs.

 

That's capacitors. Tomorrow, we'll be doing transistors.

I've been assembling my own PCs for a few years so I know quite a bit about bulging and leaking caps!

 

"But for smoothing, bypassing, or decoupling applications like in power supplies, the capacitors work additionally as AC resistors to filter undesired AC components from voltage rails. "

I think it is the smoothing out current function this one assumes it is next to the two main cylindrical caps in the power supply. As I was drawing maximum current maybe there were voltage spikes and combined with old age, low cost component etc. it got the better of it? The pop sound is the rupture of the enveloppe and it spewed similar kind of grey gunk that comes out of leaking caps.

 

When the tin can caps pop they can do a real fireworks display! I had one go in a CRT computer monitor once, just before a very important presentation to a client of course...

Houston we have a problem...

 

So I decided to install the hidden wire brake switch and not being concentrated had a plug error moment... Tiny spark, no more PAS. More mucking about with tiny cheap wires with cr...y insulation tomorrow then. I was hoping to be riding

The hidden wire brake sensors have red 5v, yellow ground and blue signal wires.

Yes I read your post on ES before I started but I think I may have plugged the brake sensor into PAS plug by accident... No, the battery wasn't plugged in so just the juice from the controller made the spark.

 

I'll look at it in the light of day when I get up in the afternoon.

There isn't any juice in the controller when either the controller or battery are switched off. If you had a spark, either the battery was connected and the controller was switched on and you connected 5v to ground, or you connected a live battery wire to the PAS, which will have instantly killed it.

 

Connecting 5v to ground can wipe out the 5v regulator, so check that you have 5v on the throttle or PAS before doing anything.