Battery charge cycles

[georgehenry]

That's the rub BazP, the most convenient way to charge the battery is your way so that it is always ready to be used.

That's the way I treat my silverfish batteries, mostly charging near to full or full in the garage so they are ready to use.

I guess because the replacement costs of batteries from the likes of Yamaha and Bosch are expensive, it makes sense to use them in a way that best prolongs their serviceable life.

You will have to report back to this thread to let us know how your batteries are doing in a few more years time.

My battery now nearly five and a half years old and still performing like it did when new is exceeding the expectations I had for it when I bought my bike.

So on a crank drive bike the battery seems to be the component you do not need to worry about. Now the motor, that is a different story.

My Yamaha motor was replaced after two years use under warranty when the bearings developed play.

 

[Nealh]

Fully charging and leaving them in that state isn't down to how many years they last.
Any effect is measured in total charge/discharge cycles and capacity retention over its usable life, it isn't as simple as some users assume it to be.
That said a battery used regularly daily /weekly will be more efficient and cost effective then some that are only used a few times a year.

The guys on ES who carry out all sorts of testing and different charging regimes all tend to agree that charging to 4.2v per cell reduces the life cycle of Li batteries.

 

[georgehenry]

My last ride to work today before three days off, setting off at 11:40. Lovely ride in beautiful countryside. Came across many more people than normal but it is a bank holiday so to be expected.

Used even less battery capacity on my 12 mile ride to work than the day before yesterday, 26%. I had a good look at the sheep and their fleeces looked thicker than I had thought the other day so they should be OK for the winter!!

Used less on the 10 mile road ride home, 32%.

The exercise makes a big difference to my nearly 59 year old body.

At this rate both me and my bike are going to wear our before the battery!

 

[RobN]

I had a good look at the sheep and their fleeces looked thicker than I had thought the other day so they should be OK for the winter.

You can get locked up for that you know...!
Worrying sheep..!

 

[georgehenry]

Baa humbug

I do not think the censor would be happy if we embarked on the many sheep jokes from the 80's!

 

[Nealh]

Baa humbug

I do not think the censor would be happy if we embarked on the many sheep jokes from the 80's!

As long as you wasn't wearing wellies they were safe .

 

[georgehenry]

Our minds are working on the same sad lines!

 

[BazP]

Fully charging and leaving them in that state isn't down to how many years they last.
Any effect is measured in total charge/discharge cycles and capacity retention over its usable life, it isn't as simple as some users assume it to be.
That said a battery used regularly daily /weekly will be more efficient and cost effective then some that are only used a few times a year.

The guys on ES who carry out all sorts of testing and different charging regimes all tend to agree that charging to 4.2v per cell reduces the life cycle of Li batteries.

That was partly the point of my post. When my battery packs up how will Iknow if its life cycle has been reduced? Exactly how long is it supposed to last given optimal conditions?

 

[Nealh]

That was partly the point of my post. When my battery packs up how will Iknow if its life cycle has been reduced? Exactly how long is it supposed to last given optimal conditions?

In general the cycle charging is only theoretical unless one is OCD and note down every charge cycle etc etc & even mileage. To get the deemed 700 cycles or so most users would need to see probably more then ten years use or a regular user 5 - 6 years of daily use clocking up the miles.
I don't but my regular use batteries I know, have roughly over six years have been charged once a week so about 300 odd charge cycles though not all from empty so probably less then that.

ES users carry out cycle testing repetitively over several months some using lipo and some as recently using various 18650 cells under a set criteria. These tests are totally independent and not even ones that you can get from the manufacturers.
Using a 2.5a charge to 4.1v and 1a discharge to 3.3v to represent average use on lower power settings. After 700 cycles some cells retained >90% capacity even up to 95%, the LG cells in general came out top of the class, the Samsung 29E also proved it can be a great cell to use.
Surprisingly Panasonic/Sanyo cells were near the bottom of the class. PF cell < 80% capacity and the GA about 85%.

Take note of the lower charge rate used of 4.1v per cell.
They have proved that the 0.1v difference in top end charging can and does increase cell life cycle dramatically above the claimed 300 - 500 most cell specs recommend when using a 4.2v top end charge.
Some have used a 4.05v top end charge to even extend the cycle life further towards 1000 cycles with little capacity loss.

In the greater picture of things unless you are charging nearly every day or every other day not many will accomplish 700 cycles within six years, then after that cell ageing will come into play as the chemistry will slowly decline.

I myself have been using a 4.1v top end charge with out balance issues for a year now, though do carryout one full balance charge twice a year. Range wise I'm not seeing any loss in real usable terms. Typically having a voltage readout on my LCD, I see that usage from 4.2v per cell group to 4.1v disappears very quickly and holds very little in capacity. The first 0.1v is only good for about 2km riding, typically < 100 - 150 mah of the total cell capacity is retained within the top end voltage of 0.1v.

 

[Nealh]

Life cycle use will show up as a decrease in range as the battery ages.
From new and after some use most will know the total range they can get out of a battery from 4.2v down to lvc of about 3.2v/3.3v. As this range decreases with use one can make a few easy calc's to see to what effect capacity is declining % wise, though it doesn't give a cycle life indication unless you actually log all of your charge data.

I expect the likes of Bosch etc, etc where info is stored via software , then diagnostics can produce a report.

 

[vfr400]

That was partly the point of my post. When my battery packs up how will Iknow if its life cycle has been reduced? Exactly how long is it supposed to last given optimal conditions?

Two things happen to batteries. If it's a crappy one, usually after someone didn't use it for a long time, it simply dies.

If you have a reasonable battery and use it fairly regularly, it'll probably last forever. What happens is that the capacity gradually goes down and it beclmes saggy. By "saggy", I mean that the voltage drops more when you take any high power from it, then the voltage bounces back when you take low or no power from it. Both those symptoms get worse and worse until you get fed up with it and decide to buy a new bike or battery. Effectively your range gets less and less.

 

[BazP]

Two things happen to batteries. If it's a crappy one, usually after someone didn't use it for a long time, it simply dies.

If you have a reasonable battery and use it fairly regularly, it'll probably last forever. What happens is that the capacity gradually goes down and it beclmes saggy. By "saggy", I mean that the voltage drops more when you take any high power from it, then the voltage bounces back when you take low or no power from it. Both those symptoms get worse and worse until you get fed up with it and decide to buy a new bike or battery. Effectively your range gets less and less.

Thanks for all the info. On my average 35 mile rides I return with around 40% battery left (two LED's on the Purion). So my battery will have to loose 40% capacity before it becomes a problem. At 73 now I'll probably be back using stabilisers before then, or I can swap it onto my Zimmer.

 

[vfr400]

Thanks for all the info. On my average 35 mile rides I return with around 40% battery left (two LED's on the Purion). So my battery will have to loose 40% capacity before it becomes a problem. At 73 now I'll probably be back using stabilisers before then, or I can swap it onto my Zimmer.

Yup, you nailed it there. People spend too much time worrying about their batteries. Even if a battery does wear out in your lifetime, by that time there will be better ones anyway - lighter, more capacity, more power or whatever you want. They improve about 10% every year, so even if your battery was in perfect condition after three years, you'd be flogging on at a 30% disadvantage to where you could be. Money is only a number on a piece of paper.