Battery do i expect to much

[vfr400]

Here:

Li-ion cells cycle ageing

This topic arise from the Pajda´s idea in another thread : https://endless-sphere.com/forums/viewtopic.php?f=14&t=102387&p=1507776#p1507776 Frustrated and tired by never ending unfruitful debate about cycle life of various Li-ion cells, I finaly decided to start some long term cycling to see...

endless-sphere.com

 

[RossG]

Bit OT I know but I have a small portable transistor radio on the shelf next to me, it holds two Sanyo Ni-Cads.
Still working with the same batteries ..... 30 years on !
Last charged about 3 yrs ago and just checked again, PWO. Can't help feeling battery technology has in some ways gone backwards. Imagine a Li-ion cell lasting 30 years

 

[Woosh]

Can't help feeling battery technology has in some ways gone backwards.

consumers prefer low weight - manufacturers give them lower weight by reducing the thickness of the lamination and the battery's longevity.
the choice of chemistry also favours lower weight over reliability: LiFePO4 lasts longer and costs about the same as Lithium-ion, but would you buy it if you know it weighs 20% more?

 

[flecc]

Bit OT I know but I have a small portable transistor radio on the shelf next to me, it holds two Sanyo Ni-Cads.
Still working with the same batteries ..... 30 years on !
Last charged about 3 yrs ago and just checked again, PWO. Can't help feeling battery technology has in some ways gone backwards. Imagine a Li-ion cell lasting 30 years

NiCads lasted many years on e-bikes too. It's all about cell density/capacity. A NiCad D cell was typically 5ah, the successor NiMh D cells 10ah but much shorter lived.

Satellites use Li-ion to normally last 10 years and near to 4000 daily charges, and when satellite replacement launch programs are delayed, many more years and charges. Again this is due to low density lower capacity large cells and no-one knows how many years they could last.

E-cars do the exactly the same to get 10 plus years from Li-ion.

So Li-ion can do it for e-bikes, if you'd be content with very short ranges and/or batteries the size of two large pannier boxes.
.
The battery on my electric car is the blue box area, but you wouldn't want to carry that about!

 

[Hixyhicks]

Im learning to ride my bike with regards to battery conservation.I rarely used over peddle assist one now.This morning i rode to work and used a slightly different route with less hills,whilst doing this i tried to keep watts low or very low on my display.Im now left with 54.1 volts left and hoping that will get me home?Im concerned that charging my battery twice a day is hurting my battery.Is it do you think? I realise batteries degrade over time But it would nice to get 18months out of it.

 

[Nealh]

How the battery depletes and range is down to cells used and their specs.

 

[Hixyhicks]

Hello Neath,samsung 35e

 

[Nealh]

The 35E is a good cell though doesn't fair well with high current.
As with all 3500mah cells you can't have both range and current either take the range they offer at low current draw or have the higher current draw and expect shorter usage time. 4- 5a draw per cells in parallel will make the battery work quite hard.

 

[Hixyhicks]

Ok thanks again Neath.

 

[Hixyhicks]

I cycled home and back to work this morning without charging the battery,so I'm well pleased.I had 49.6 volts left on the battery.So maybe i could of made another run home,but i dont want to chance running out of juice.Now i only have to charge the battery once aday,which should make the battery last longer?

 

[Hovlev2]

I peddle all the way and hard .its great exercise.

So why do you have an ebike?

 

[Hixyhicks]

Because im not a lazy ** and couldnt cycle 30 mile a day on a normal bike,I enjoy the excercise.

 

[wheeliepete]

I cycled home and back to work this morning without charging the battery,so I'm well pleased.I had 49.6 volts left on the battery.

That's a good voltage at which to recharge. Regularly running your battery down to near empty is recognised as effecting capacity over time. As nealh has said, 35E's are decent cells, so as long as you avoid prolonged high power use, then they should last well.