The Sunlova battery beat me! Woohoo!

[John L]

Today I went out on my bike with the sunlova conversion mainly to see how far I could cycle before the battery gave up.

Well I had to give up before the battery did!!

Once moving I twist the throttle to full and keep cycling as best I can. I wanted to see if this method would do the 32 mile round trip to work on one charge.

After I passed the 32 mile mark there seemed to be plenty charge left so I went on. After 38 miles i was expecting the battery to die at any moment - the LEDs were showing half charge nearly all the time at that stage. I was amazed when i reached 40 miles. Now I was cycing very locally so that when the battery died I wouldn't have far to cycle home.

At 44 miles I gave up - 2 1/2 hours on a bike is a long time when you're not used to it. I decided to see if I could go another mile using the motor only. Amazingly it did and the battery still wasn't dead!!

I cycled over 45 miles at 16.6 mph. I was sore and tired but grinning from ear to ear The bike isn't set up brilliantly - the front brakes rub a little (the front wheel is a little out of true) and the derailleurs need some work (workstand on the way) so I feel there is a little bit more in it

John

 

[Fordulike]

Good to hear the battery is up to the job.
What's the model series of the 8Fun motor?
Also, is it any good up the hills and could the throttle be easily replaced with a different type?

 

[Old Timer]

Today I went out on my bike with the sunlova conversion mainly to see how far I could cycle before the battery gave up.

Well I had to give up before the battery did!!

Once moving I twist the throttle to full and keep cycling as best I can. I wanted to see if this method would do the 32 mile round trip to work on one charge.

After I passed the 32 mile mark there seemed to be plenty charge left so I went on. After 38 miles i was expecting the battery to die at any moment - the LEDs were showing half charge nearly all the time at that stage. I was amazed when i reached 40 miles. Now I was cycing very locally so that when the battery died I wouldn't have far to cycle home.

At 44 miles I gave up - 2 1/2 hours on a bike is a long time when you're not used to it. I decided to see if I could go another mile using the motor only. Amazingly it did and the battery still wasn't dead!!

I cycled over 45 miles at 16.6 mph. I was sore and tired but grinning from ear to ear The bike isn't set up brilliantly - the front brakes rub a little (the front wheel is a little out of true) and the derailleurs need some work (workstand on the way) so I feel there is a little bit more in it

John

Nice one John

 

[John L]

Good to hear the battery is up to the job.
What's the model series of the 8Fun motor?
Also, is it any good up the hills and could the throttle be easily replaced with a different type?

The motor is the SWXK model.

Its hard to say how good it is up the hills - this is the only electric bike I've cycled so I've nothing to compare it to. The only thing i can say is that I haven't hit any slope yet that caused me any real problem. Now that I know I can go 40 + miles I'll take a spin up some slopes that should seriously test the battery and motor (i'll keep you posted).

In relation to the throttle I'm afraid I don't know. On the face of it, it seems like a simple arrangement. Two leads to the controller from the throttle which as flecc described as essentially being a switch. I'm going to adapt it to a half throttle (another hacksaw job) and see if I can find a way of keep it on full throttle without holding it all the time.

 

[garrence]

What's the battery spec? Is it a 250W motor?

 

[John L]

What's the battery spec? Is it a 250W motor?

The battery is Li-ion 36v 9000mAh/324Wh - doesn't sound the most powerful but it does the trick. The motor is indeed a 250W motor.

John

 

[Vikki]

Wow! The battery and you did well Nice one

Vikki.

 

[Caph]

I came across this thread earlier today and was amazed at the distance achieved on full throttle so I headed out to the Peak District on my Sunlova QSWXK (also 9Ah battery) conversion with my thumb throttle on full.

I made it to Matlock Bath which is 18 miles and checked the battery which showed 20% remaining. The route is half hilly with a couple of killer hills, and half flat, but overall it is quite a climb up to Matlock Bath so I knew the battery had done a lot more than half the work. I was quite surprised that it managed to get me all the way back home and only died on me on the last little hill up to my house.

So all in all it managed 36 miles on full throttle at an average speed of 15.75mph. I've got to admit that's about 10 miles more than I thought I'd get out of it on full throttle. I'm very impressed. I'm going to have to check out the range on low power, I wouldn't be surprised if it can exceed 60 miles.

 

[Scottyf]

The sunlova kit does push lots out the battery. Usually down to the controllers being on the small side but it does mean you get a decent range out the battery. GLad to your enjoying your kit.

 

[Caph]

I noticed that the controller is on the small side. What's the relationship between controller size and efficiency?

I forgot that my cycle computer is a bit out when compared to GPS so that makes it 34 miles, but I was deliberately not putting in much effort and letting the battery do the work so I'm still very impressed.

 

[Scottyf]

When I checked my controller it was only a 6amp rated, 13amp max. @ 36v nominal input it could deliver a max of 468watt. So even when the controller is pulling maximum amount of amps for say a full journey (Which it wont) on throttle only on the standard 9ah battery (324watt) it should last 42mins.

But you'd have to be going up a hill constantly at 8mph for 42mins to directly get that usage. As you averaged over the 15mph assist speed amp's from the controller would more than likely be hitting around the 4/5 mark or less which would give you 120mins range. At the 16mph you did pull that would be a range of 32miles.

So as the controller is quite low for amp's it extend's your range. As it forces you to pedal more. Even on max assist it would never allow that much electric to be eaten up by the motor.
I found the sunlova kit good and it helps just keep you going. On my hybrid bikeI only really used it to get up to speed 15mph and then ease of the throttle and carry on pedalling myself. I'd complete an 18mile round trip on 2.2ah (@best, worst 3.3ah with a head wind and me hungover). Theoreticalling giving me a huge range on a 9ah battery.

But in essence the smaller the controller amp's the longer range however the lower the assistance.

 

[NRG]

The larger controllers with more FETs can handle more power and I believe the internal losses are less due to the FETs being in Parallel, but controllers are very efficient voltage to current converters anyhow probably being no worse than 98% efficient. limiting the amount of current drawn from the battery will extend range though, I'm still running my Alien at 12.5amps on an ageing battery and range in this configuration is the same as it was when new the cost though is I need to put more effort in on really steep hills.