Wisper Battery Failure x 2

[Kudoscycles]

David(Wisper)>
First of all,enjoy your trip to China-I have been visiting China for over 7 years now,I usually go in the spring or autumn when it is less humid in the south and bearably cold in the north,I usually travel for 3 weeks,I still find it an exciting country-Kudos and Rally Design now have over 50 suppliers in China,I have visited most of the cities adjacent to the eastern seaboard, my favourite is Hangzhou,especially around the West Lake area. Do you fly Virgin or British Airways?
to answer your latest posting.
1. I accept that Lifepo4 has lower energy density,about 20-30% -about 0.7kg on a 10Ah battery,this only starts to be a significant factor when using 16 plus Ah batteries-I think it is horses for courses.
2. I am advised that LifePo4 has an operating temperature range of -45C to +70C whereas for LiMn2o4 or LiCo2 the prefered range is -20C to +50C,above 40C does a lot of harm to these battery types and should be avoided.
3. There is a number of patent battles around the world of most relevance is the Winston Chung patent ownership battle but China has a way of sorting these matters out(money!),my manufacturer is not concerned.
The patent battle between A123 systems,Hydro-Quebec and the University of Illinois has recently been settled. The CEO of A123 systems described this as a win-win situation for all paving the way forward for increased LifePo4 production. As a result of the settlement Sony has announced an increase of LifePo4 production to meet the needs of EV's and E-bikes.
If you look on my posting 'NEVER BUY ANOTHER BATTERY AGAIN'-this is an exciting development on LifePo4 technology by the Taiwan Co,Advanced Lithium Electrochemistry Co Ltd,claiming 5400 cycles.
David>we are not building F1 cars where the vehicle can be closely monitored and maintained,the LifePo4 battery is not fragile,it does not need constant conditioning charge. I,and my customers need an inexpensive battery which looks after itself (put it away with 80% charge,only 3% self discharge per month),I think LifePo4 was the best decision I made when entering the e-bike market and I would welcome other suppliers to follow suit-I think we need these bikes to become simpler to own,less expensive to maintain and the market will expand for the good of all.
Have a safe trip to China
Dave
KudosCycles

 

[Wisper Bikes]

Thanks Dave

I think we should agree to differ, I really dont think LiFePO4 batteries are good enough for what we are achieving already and want to continue to achieve in the future. There certainly is not enough difference in price per kWh to accept the difference in quality and performance.

We are constantly looking at new tech and if phosphate batteries improve we may reconsider.

Thanks for you best wishes for my trip, unfortunately not only do I go when it is nice and warm, I tend to go out every couple of months just to keep an eye on things. It will be wet and bitterly cold, much like myself some say!!

All the best

David

 

[Kudoscycles]

David,I agree to differ....I think we have mutual aims but from opposite directions. You may wish to check out the Taiwan Co mentioned in my new thread -which is claiming a superior LifeLo4 battery,namely Alees.
regards
Dave

 

[Wisper Bikes]

Cheers Dave, hope to see you soon.

All the best

David

 

[eddieo]

David if all goes well with developments, what sort of battery can I expect for the DaaHub kit in the future?

 

[z0mb13e]

Hi David,

I agree that the higher the initial capacity the better the prospects are for long term use of the battery - I figured that getting the 14Ah battery I wouldn't be pushing it to it's limits very often and so it would be less stressed and would last longer as a result.

However, my statement that I would have to look at a cheaper alternative is not that I am thinking short term, it's just that my disposable income is non existent thanks to the economy/wage stagnation/cost of living.

That said, things change and I may find myself in a better situation before this current battery needs replacing, in which case I would give serious consideration to your 16Ah batteries.

Hi Z0mb13e

I do understand your point, but do remember when choosing a new battery that our latest batteries will have a 20% maximum current drop in two years so will last even longer. After two years the battery will still have at least a whopping 460Wh, 100Wh more than a brand new 36V 10Ah and only 54Wh down on our older batteries when they were new. Even after three years hard use they will still have more capacity than a brand new 36V 10Ah.

The batteries we use now really are 16Ah not simply rated 16Ah, they are testing at on average 16.4Ah +-. Other batteries we have tested fall short of the published capacity by as much as 15% even when they are brand new. The battery you are using now is one of our older 36V 14Ah batteries or 504Wh. If it is down to 60% of original capacity that means you still have over 300Wh remaining, a maximum of 60Wh down on a brand new 10Ah battery.

We can go back over 6 years with our batteries and give 100% guaranteed feedback. The new cheaper 36v 10Ah batteries have not been about for more than a few months and no one really know what to expect. At half the price of a powerful Wisper battery they may seem good value but it is worth noting that you are getting much more than a third more capacity with a decent battery. It's similar to buying 16 litres of fuel instead of 10.

Using decent powerful batteries is one of the main reasons Wisper bikes feel more powerful than many others and maintain that power for more miles.

All said though we are all restrained by budgets and there is nothing at all wrong with buying what can be afforded short term. Hence the reason I will be looking at the new cheaper batteries as an option.

All the best

David

 

[bazwaldo]

Here you go Barry

Thanks Bob, you may recall though the only reason I did not become a Juicybike owner last year when looking for my first Ebike was that your 14AH Battery wasn't available at the time.
Given that my Bearprint 16AH battery is struggling with just 1 way of my work commute after just over 1 year a 10AH battery as I originally thought would not give enough range in the long term.

Barry.

 

[Deleted member 4366]

That amount of deteriation seems a bit much. I'm thinking that maybe a connection has broken to one or more cells rather than the cells just worn out. I think you should take it up with Bearprint now to see if they're going to honour their warranty. If they don't and you don't want to make a fight over it, it's not too difficult to open up the battery and have a look.

 

[JuicyBike]

Thanks Bob, you may recall though the only reason I did not become a Juicybike owner last year when looking for my first Ebike was that your 14AH Battery wasn't available at the time.
Given that my Bearprint 16AH battery is struggling with just 1 way of my work commute after just over 1 year a 10AH battery as I originally thought would not give enough range in the long term.

Barry.

I know we lost you to Bearprint Barry, but would always help you out if we could. 16AH was the right size for your journey; a 10AH battery would have been far too stressed with such regular complete discharge. It is so important to match the size of battery to the amount of discharge required - our rule of thumb is to plan to keep your battery in the 40 - 95% charge state, and so find a battery size to suit.

 

[Wisper Bikes]

David if all goes well with developments, what sort of battery can I expect for the DaaHub kit in the future?

Welcome back Eddie!

We will certainly be using LiSu on DaaHub hopefully by 2013 we would then be able to pack 36V 20Ah into the box.

All the best

David

 

[Wisper Bikes]

Hi David,

I agree that the higher the initial capacity the better the prospects are for long term use of the battery - I figured that getting the 14Ah battery I wouldn't be pushing it to it's limits very often and so it would be less stressed and would last longer as a result.

However, my statement that I would have to look at a cheaper alternative is not that I am thinking short term, it's just that my disposable income is non existent thanks to the economy/wage stagnation/cost of living.

That said, things change and I may find myself in a better situation before this current battery needs replacing, in which case I would give serious consideration to your 16Ah batteries.

Thanks Z0mb13

I do hope your situation improves, we are all suffering, the current situation seems to be never ending.

Good luck!

David

 

[z0mb13e]

Hi David,

I'm going to run the 14Ah battery into the ground! So far, despite the cold weather it is still performing well which has come as a pleasant surprise. Given that the first winter the cold weather had no affect, yet the second winter caused a big drop in battery performance, I was expecting this winter to kill it off completely. So far (we've had a few days of <4C) it doesn't seem to be affecting the battery at all!

The handle bar lights are almost always on red and the lights on the battery itself usually drop to one green and stays there so I mostly ignore them...

So right now I'm thinking 3 years is not a tall order for this battery...

 

[Wisper Bikes]

Great news Z0mb13e, please keep me informed of the performance, it should be fine.

All the best,

David