905e battery HELP

[Mr unsure]

HI
I have just rode my 905e home from work, a grand total of 3 miles.
Sometimes i pedal with assist, sometimes i just use the throttle, but as i got home i had no pedal assist or no throttle mode, and no light indicators on handlebars {IE power, full, empty} they are red, green, yellow.
Just been out to lock 905e away for the night turned the key on to check red & green lights on, raised back wheel of 905e & have throttle mode.
the battery was charged on monday, 905e not used tue, used today wed.

so if anyone can throw some light on what happened that would be great.

thanks in advance Bob

[flecc]

It might have been a safety cut-out operated Bob. These lithium batteries have them to prevent overheating and possible fire risk, and under high loadings the cells voltages can drop low and trigger the cut-out. Switching off and then on again resets the cut-out and lets the lights back on. However, after a cut-out the battery has to rest for a while for the cell chemistry to recover, and that's what may have happened in your case.

Do you have a hill on the last stretch to home where you had the throttle full on? That's the sort of thing that can trigger this, or even a long period of sustained full throttle. As lithium batteries age they become more prone to this, and it's good practice to use only the amount of throttle that's absolutely necessary and also to assist with pedalling, especially when the going gets tough.
.

[Mr unsure]

Hi flecc thanks for the reply.

I have only had the 905e about 4weeks, i purchased from new milton, so iam a bit thrown by the battery doing this sort of thing with age, as i would have thought i would have had a new battery when i purchased the bike????????

Bob

[flecc]

It will be a new battery Bob, my remark about age just indicating how age can make things a bit worse. And of course it depends on whether my diagnosis is right, though it sounds that it is.

I'm afraid lithium battery cutouts under load have proved to be a bit troublesome on all the more powerful bikes, and it's best to follow what I've posted above on using the power a bit more sparingly. I've suffered from this a lot on my two eZee bikes, both with similarly powerful 36 volt motors to yours.

The battery manufacturers were caught on the hop a bit by this, not realising just how high the demands of our bike motors can be in some cases. Battery development is showing promise though, and when you eventually come to replacement time it won't be a problem any more and you will be able to use the power with abandon.

Keep an eye on it and let me know if there is any change or whether it doesn't appear to be a cutout as I think. I was replying to David Miall, the Wisper MD a few minutes ago on another matter, and mentioned your posting to him, so he is aware of the problem you experienced.

regards, flecc

[Mr unsure]

A BIG THANK YOU TO YOU Flecc i will let you know if it persists.
Cheers for the mention to wisper MD

Bob

[Mr unsure]

Hi
Today i rode bike home from work & it cut out twice, this was with pedal assist only on the hill to my house and the second time was on a 100 yd flat stretch to my front door still only on pedal assist.

Wisper say in the Ad it is dependable? nothing dependable in 3 cut outs on a 4week old bike.

So wisper do please contact me Bob

[Wisper Bikes]

Hi Bob

Drop me a line at miall@aol.com and I will sort you out if you are not getting any Joy from New Milton which I find extremely surprising. Have you spoken to them about the problem?

If not our telephone number is;

01425 627 641

Doug or Phil would be only too pleased to help you.

I will give them a call now an let them know you will be in touch.

Thanks Flecc for your input (I haven't seen your email yet).

Best regards David

P.S. I have spoken to Doug and Phil at New Milton and they know nothing about your problems. The only technical call we have had in the last few days was someone asking if they could totally de-restrict the speed on their bike, was that you?

I would suggest that it is always better to make contact with your point of purchase prior to trying to find answers on the Pedelec forum. If the battery is faulty and you have not tampered with it, it is covered by our warrantee.

[sjoroveren]

I live in Italy and I bought a Wisper 905Se from German.
I bought it about 2 months ago, but used it only the last 2 weeks, I have been abroad for work.
I had the same problem with my 905 SE, but I have only pedal assist, no throttle or the 2 buttons red and green, because they were no assembled, and I received no instructions how to assemble them.
Anyway the pedal assist is enough for me, the only problem is that the 905Se tries to run at 25 Km/h anyway, so if there is a hill I must work a lot, or it "dies" after a short way.

Today the 905Se died at all, no led, no lights at all in the "dashboard", I was going on a mountain road, that I usually do with my normal (not electric ) bicycle and it stopped without notice.
I was quite disappointed, I checked the fuse and it was ok, after some times it started again but I could not come home, down the hill.... now I am trying to charge the battery, but anyway I though the e-bike should climb a hill that I usually climb with my city-bike.
The bike is new, there is warranty, I hope it is a defect of my bike and not a limit of the 905Se.

Sorry for my English, as I told I am from Italy, and I stopped with school a lot of years ago, i think I should need a few lessons again

[Wisper Bikes]

Good day Sjoroveren

There is absolutely no reason that your battery should have died so abruptly. It does sound as if you have a problem with the German wiring.

You should contact your supplier as soon as possible to find a solution, if they cannot or will not help please contact me directly and I will see what we can do to help.

david@wisperbike.com

Best regards David

[chess]

i have been thinking of purchasing a wisper for a 14 mile each way ride to work; done at present on unassisted bike. the comments on battery problems make me unsure whether this is the bike for such regular usage-long steady gradients and wind, always wind!
what other bikes may be suitable?
any advice welcome
chess