Hi all.

 

;TLDR; - I love it but I need to find some cheap batteries!

 

I'll come right out and say that I've been a lycra road bike warrior for the last 5 years and looked at eBike with contempt and scorn. Until I was put in the unfortunate position of facing a rather hefty bill to fix the gearbox on my car, and hating the commute to work on the train. So I started to seriosuly consider an eBike as a viable method of tranport as a replacement for the car.

 

I have cycled to work on many occassions but a 50 mile commute back to back over the course of the week (notching up 250 miles) along with weekend club rides nearly killed me so I usually only take the raod bike into work once or twice a week.

 

I started reading reviews for various eBike and lurked on this very forum before dropping some notes on a Haibike sDuro Trekking 5.0 which, although is about as far away from my 7kg carbon fibre Di2 bike, appeared to tick all the boxes as a commuting machine.

 

It was delivered last Friday afternoon. I cycled home with the biggest grin I've ever had on my face. It propelled itselft and my 110kg of mass effortlessly up some of the steeper climbs on my route and I actively went off course to try some steeper gradients, much more than I'd do on my normal commute. I ended up clocking 40 miles on the way home (nearly twice as far as I needed to go!) and loved it.

 

The only negative for me was the very restrictive 15mph speed limit. I regularly cycle the commute on the road bike at an avergage of about 17mph and have done it at over 20mph a few times so feeling the bike bog down as the motor stopped assisting was a bit frustrating.

 

I *may have* therefore reloacted the speed sensor and magnet to the point where I no longer have any concerns about the bike bogging down at the speed.

 

This has brought me some puzzlement...

 

The battery is rated at 500WH, and the motor is a 250W Yamaha motor.

 

Theoretically, I should get 2 hours out of the battery under full load.

 

My commute this morning was about 70 minutes at about 3/4 power (that's the power assistance indicator showing about 3/4 up the chart for most of the way). The battery and range indicator was dropping ridiculously quickly. Before I set off, I was getting an idicated 45 mile range (on HIGH assist level) and by the time I got to work it was reading 6 miles. So the faster I go, the less range I have to play with. I can accept that, but it was touch and go on whether I'd get to work assisted or whether I'd have to do some pedalling! and still doesn't explain the whole 500WH/250W thing - I reackon I'd have got another 5 minutes out of the battery at most before it t was completely drained.

 

I then started looking at battery options. Maybe having one at work fully charged and carrying a fully charged spare with me just in case. That is until I saw the phenominal prices of these battery's - £800 for the Yamamha 500W battery, and another £150 for another charger. A bit excessive for what is a bunch of 18650 LiPo's.

 

Which left me wondering whether or not a homebrew battery pack could be made compatible with the Yamaha system?.... has anyone successfully done this?

The motor is rated at 250w maximum continuous power. That's just a number on a piece of paper for legal reasons. It has nothing to do with how much power the motor produces and consumes from the battery.

 

Under heavy load, like climbing up a hill, the maximum power from the battery is something like 700w. Derestricted, in a high gear and travelling fast, I can imagine about 400-500w depending on your cadence.

 

I don't know if it's possible to use alternative batteries with the Yamaha system. In systems like that, there's normally some communication between the controller and the battery before it'll give power. That means that probably your only option would be to run another battery in parallel to your main one, which is complicated.

 

IMHO, you're a bit stuck. there's other bikes that don't have these problems. It's a shame you didn't know about the limitations when you bought the bike.

Under heavy load, like climbing up a hill, the maximum power from the battery is something like 700w. Derestricted, in a high gear and travelling fast, I can imagine about 400-500w depending on your cadence.

 

Thanks, I didn't realise the motor could put out over the stated 250w. That falls in line with what I experienced this morning then, and explains the rapidly discharging battery!

 

I'm happy to take it a bit easier on the commute anyway, I actually took the time to appreciate the scenery this morning instead of blasting along as fast as I could in lycra.

£150 for another charger.

 

The charger cost is rather annoying, but TBH, if it was me and I was going to commute regularly, I'd suck it up and just buy another one to keep at work. By far the easiest solution.

Enjoy your bike - I bet its fantastic!

The charger cost is rather annoying, but TBH, if it was me and I was going to commute regularly, I'd suck it up and just buy another one to keep at work. By far the easiest solution.

Enjoy your bike - I bet its fantastic!

 

I don't mind carrying it all with really - the pannier rack (and bags that'll soon be arriving) provide ample space for any charger and batteries I want to bring along with me. It's the cost of the batteries that gets me. Absolutely ludicrous. There must be someone out there who's managed to hack this system and splice in their own homemade battery packs.

There are some aftermarket batteries available in Germany but they are still expensive.

http://www.ebay.de/itm/eBike-AKKU-36V-13000mAh-fur-Haibike-Sduro-Fulllife-Fullsix-Yamaha-Down-Tube-Type-/371997063510?hash=item569cc0b956:g:MrcAAOSwCkZZVQjU

It is also possible to fit an extender in parallel with the original battery but you must make sure the voltages are identical before connecting them together.

https://www.pedelecforum.de/forum/index.php?threads/sduro-mit-doppelter-akkukapazität.46619/

Google translate is your friend here.

If anybody wants to have a go at that with any bike, be aware that you must disconnect the auxiliary battery when charging either battery. I hope that German guy knows that. Somebody tell him if you speak good German.

He knows it's in his text elsewhere

Typically it takes 5 full charges before a li-ion battery will provide its full capacity. You might be rushing a little, and I'd give it some time yet before you decide anything major. I think a second charger is your best bet for now if you can't easily carry your existing charger to work.

Exceeding the 15mph limit is of course going to reduce the range.

I agree , give it some time, my 500watt battery range increased after about 5/6 charging cycles. Having said that,if your speed is above 16mph your not using any assistance so your range should massively increase.

I don't mind carrying it all with really - the pannier rack (and bags that'll soon be arriving) provide ample space for any charger and batteries I want to bring along with me. It's the cost of the batteries that gets me. Absolutely ludicrous. There must be someone out there who's managed to hack this system and splice in their own homemade battery packs.

http://www.bga-reworking.co.uk/insat-li-nmc-ebike-battery-10ah-24v-36v-48v.html

 

you will need a case and bms tho for the Yamaha batt but with a bosch batt the bms must not loose power when you recell it other wise you brick it but jimmy said its no problem just costs more;)

Having said that,if your speed is above 16mph your not using any assistance so your range should massively increase.

 

Yeah, I'm definitely not assisted past 16mph

 

I commuted entirely on the eBike last week and loved it - even in the torrential downpours. I've managed to optimise the way I ride, going down to "eco" assist for a lot of the time and using "standard" for climbs and fast roads. I hardly need to touch the "high" anymore as I've gotten used to the bike and the weight - and to top it off, I've lost 8lbs in a week so it's definitely paying off! My average speed is hovering just under 20mph which is fantastic considerng the sheer weight of the thing (with loaded panniers and my bulk on top) and I'd struggle to maintain that speed in both directions over the course of a week on my road bike.

 

Very happy with it!