battery life seems fairly poor for me about 4000 miles

[georgehenry]

I bought a Haibike sDuro HardSeven Yamaha in 2015. It has a 400Wh battery. I use it to commute to work and back. Yesterday I rode 14 miles cross country and used 31% of the battery giving a theoretical range of 45 miles, charged the battery back up at work and then rode 10 miles on the road home using 38% of the battery giving a theoretical range of 26 miles. Riding home I want to travel faster and use higher levels of assistance on the hills I climb. My bike assists above the cut off point and I average around 20mph for the 10 mile road ride home.



My cross country route is really what I bought the bike for and is nearly all off road including some quite challenging bits where I use lowest assist level eco of the three I have or motor off. I have a pannier rack and carry two fully loaded panniers with stuff I need for work. I also weigh over 100kg.



My total mileage as of last nights return trip is 10,468 miles.

This is the original battery that will be four years old in March and the amount of battery I use has hardly changed at all since I bought the bike.

I always bring the battery into the house and leave it at the 60% charge level it has reduced to on the ride home until I need to use the bike again. This can include not being used for three weeks if I go on a main family holiday and recently six weeks as I had a minor operation and was told not to ride.

I try to charge the battery back to full as close to my departure time for work as possible. I am lucky to be able to leave my bike in a heated room at work where I can also charge the battery back to full.

However I have to leave the battery charger attached as I am generally away from the room where I charge the bike until the end of my shift of around 9 hours. The Yamaha charger does appear to switch of (ie light goes out) when the battery is fully charged. I am sure that my battery is starting to lose some of its capacity but in real terms works pretty much as well as it did when new.

I also have an old 2011 (still going strong 20,000 miles plus) Oxygen battery behind the seat post rear hub drive bike that I use for shopping and many other errands and due to the battery being much more difficult to remove it stays on the bike in the garage. It has a cheap Chinese charger. The batteries seem to last about three years. The last battery I bought was under £200 from ebay including charger https://www.ebay.co.uk/itm/36V15-6Ah-Lithium-ion-Battery-E-bike-Silver-fish-with-Cellphone-charging-USB/222214730187 . I do use a timer plug in the garage to limit how long the charger stays on. I do use it to ride to work (20 mile round trip charged at work) on early shifts where I am riding on the road in both directions. I do not use a timer plug at work (though I might consider doing this) and the charger keeps charging the battery until I disconnect it to ride home.



So I do not think you need loads of technical knowledge to look after your battery. If possible remove your battery and store it in the house (but do not worry too much if you cannot). Do not fully charge the battery and then not use it. If you have a cheaper Chinese style charger limit the time it continues to charge the battery with a simple timer plug. Try to charge your battery to full as close to when you intend to use it as possible. Store it for longer periods at about half full. As these batteries slowly degrade over time anyway ride your bike as much as possible.

Happy riding.

PS I think torque sensor crank drives are probably a bit kinder to a battery than cadence and in my case full throttle controlled hub motor bikes, but I really like them both for different reasons.

 

[Sturmey]

Hi. Just to add my piece. There seems to be some disagreement over what happens when the battery becomes charged and the light turns from red to green. Well, from my knowledge and observation (and taking into account differences between models etc.), I would say it also depends on whether the battery is balanced or not.
When the battery is balanced, (e.g 10s,36v) all cells reach 4.2 volts, the whole battery voltage rises to 42v and the charger turns off /light turns green.
When the battery is not balanced, although the battery may go to 42v and the charger will go to green and turn off, some cells may be high up to typically 4.28 v and its possible for others to be low at say 3.9v. What happens then is that the high cells will be leaked back down and this will lower the overall voltage of the battery.
This may cause some chargers to turn back on again if its still plugged in for perhaps only a few minutes (and the light to go red on some chargers) to raise the cell voltages. Again, the BMS will leak down the higher voltage cells. This cycle of the charger coming on for a few minutes every few hours keeps repeating itself until the battery cells equalize.
Hence some suppliers recommend leaving charger on once or twice for 24 hours to balance new batteries or batteries with poor performance.
However, its also true that this puts a certain amount of pressure on the cells and should only be used when necessary or when battery performance is poor/unbalanced/ battery not used recently/ new battery left in storage for long time etc. Bear in mind that an unbalanced battery puts pressure on certain cell groups.
Some suppliers (e.g. cyclotricity) also suggest leaving the bike turned on during this process. This seems to have an effect in that the idle controller bleeds about 100-200 mA from battery and causes voltage to drop quicker, causing the charger to switch back on more frequently.
Again to mention, there are differences between chargers and BMS and some/many bikes may be different to this.

 

[James63]

I have a Bosch Performance Line motor, Bosch Powerpack 500wh equipped hybrid bike. The shop I bought it from did a diagnostic check of the battery the other day. It seems that I have done 279 miles on 5.6 charge cycles. When the motor has been assisting, I have been mostly (and about equally) in eco mode and tour mode and about 25% of the time in sport or turbo mode.

It seems that cycling in a busy and hilly city (Bristol), stopping and starting lots I have been getting about 50 miles per charge. That was quite acceptable to me. Without all the stopping and starting , I would get a considerably longer range and when my currently quite feeble legs get a bit stronger that should help quite a bit too.

 

[KirstinS]

This thread is a great example of "a little bit of knowledge is a dangerous thing".

Andy, are you aware that the majority of advice that you offer on this forum is at best, out-of-date and at worst, just plain wrong?

Well absolutely !

Where is d8veh with some Ezekiel 25 :'17 when. you need him eh ? Lol

 

[SteveB1262]

This thread is a great example of "a little bit of knowledge is a dangerous thing".

Andy, are you aware that the majority of advice that you offer on this forum is at best, out-of-date and at worst, just plain wrong?

I'm certainly aware of that but as they say 'you can lead a horse to water but you can't make it drink'. Thank you for your comment as I was thinking of banging my head against the wall!

 

[SteveB1262]

I have a Bosch Performance Line motor, Bosch Powerpack 500wh equipped hybrid bike. The shop I bought it from did a diagnostic check of the battery the other day. It seems that I have done 279 miles on 5.6 charge cycles. When the motor has been assisting, I have been mostly (and about equally) in eco mode and tour mode and about 25% of the time in sport or turbo mode.

It seems that cycling in a busy and hilly city (Bristol), stopping and starting lots I have been getting about 50 miles per charge. That was quite acceptable to me. Without all the stopping and starting , I would get a considerably longer range and when my currently quite feeble legs get a bit stronger that should help quite a bit too.

I would say that about mirrors my experience. I'm still doing a running total on one charge and have done, so far, forty miles with three bars still remaining on the indicator. My predicted remaining miles is still confusing me as at the start of the last ten mile ride it read 16 miles but by the end of the ride it was 28 miles!!! Go figure! I've about given up on that info on the computer. I predict my mileage will reach 85+ miles before requiring a charge BUT my local terrain is virtually flat and 80+% of my use is off and about 20% ECO. I took terrain into consideration when choosing my battery and the advice given on my predicted style was to stick with the 300w battery. They were absolutely spot on. The whole buying and use experience has gone 100% as predicted but I bought the bike for excercise not for transport. 50 miles around Bristol, which I am acquainted with, would indicate your riding style is very similar to mine as it's not the flattest of areas. I would consider 50 miles there pretty damn good even on the 500w battery. I wouldn't mind betting you would get 120+ on a 500w in my locality as long as the weather/wind is reasonably kind.

 

[SteveB1262]

Hi. Just to add my piece. There seems to be some disagreement over what happens when the battery becomes charged and the light turns from red to green. Well, from my knowledge and observation (and taking into account differences between models etc.), I would say it also depends on whether the battery is balanced or not.
When the battery is balanced, (e.g 10s,36v) all cells reach 4.2 volts, the whole battery voltage rises to 42v and the charger turns off /light turns green.
When the battery is not balanced, although the battery may go to 42v and the charger will go to green and turn off, some cells may be high up to typically 4.28 v and its possible for others to be low at say 3.9v. What happens then is that the high cells will be leaked back down and this will lower the overall voltage of the battery.
This may cause some chargers to turn back on again if its still plugged in for perhaps only a few minutes (and the light to go red on some chargers) to raise the cell voltages. Again, the BMS will leak down the higher voltage cells. This cycle of the charger coming on for a few minutes every few hours keeps repeating itself until the battery cells equalize.
Hence some suppliers recommend leaving charger on once or twice for 24 hours to balance new batteries or batteries with poor performance.
However, its also true that this puts a certain amount of pressure on the cells and should only be used when necessary or when battery performance is poor/unbalanced/ battery not used recently/ new battery left in storage for long time etc. Bear in mind that an unbalanced battery puts pressure on certain cell groups.
Some suppliers (e.g. cyclotricity) also suggest leaving the bike turned on during this process. This seems to have an effect in that the idle controller bleeds about 100-200 mA from battery and causes voltage to drop quicker, causing the charger to switch back on more frequently.
Again to mention, there are differences between chargers and BMS and some/many bikes may be different to this.

I doubt ANY modern battery isn't equipped with a balancing circuit. The difference, it seems, between mine and the one you describe is, the battery itself has a state of charge indicator in the form of five illuminated green LEDs. When charging the indicator flashes simply on the level indicator at the top of the current state of charge. When number five stops flashing the lights go out and current from the charger is cut off. According to Bosch the charger only fires up to give a top up to cover natural drain and then goes off again ad nauseum... This mean the absolute minimum of stress on the cells whilst keeping the charge. I, like everyone else, am aware that older chargers do not shut off but maintain a trickle charge which, as you state, will keep the cells under pressure possibly resulting in swollen cells. Chargers have evolved considerably since then to eliminate that problem so as stated by another poster, some of the info on this thread IS just plain wrong but it does no harm whatsoever to play it safe if anyone is unsure of the type of system they have.

 

[Deleted member 128]

My predicted remaining miles is still confusing me as at the start of the last ten mile ride it read 16 miles but by the end of the ride it was 28 miles!!! Go figure!

The predicted remaining miles probably depends on the use you're making of the battery, if you made less use of it than on your previous ride then the predicted remaining miles could go up.
The same thing happens with cars where the predicted range of the remaining fuel in the tank can sometimes increase.

 

[danielrlee]

At risk of sounding somewhat of a pedant, a lithium chemistry charger will never output what is commonly known as a “trickle charge”. Due to the CC/CV nature of a lithium charge profile, the charging current will always taper off to zero if the charger is not switched off, or disconnected from the battery. A true trickle charge can only occur during a CC charge profile, where a constant current is sunk into a battery, which causes the voltage to continue to rise indefinitely.

 

[sjpt]

The predicted remaining miles probably depends on the use you're making of the battery, if you made less use of it than on your previous ride then the predicted remaining miles could go up.
The same thing happens with cars where the predicted range of the remaining fuel in the tank can sometimes increase.

Yes, but in a car the result is reasonably damped, whereas on a Bosch ebike system it changes absurdly according to a very tiny time/distance history

 

[Andy-Mat]

As I keep repeating, everyone must choose as to what he believes or not.

I have not only managed to get my last bike battery to last far longer than this topic suggests is "normal", but with my new bike and battery, I am well on my way to exceeding the 4000 miles that the topic (correctly to my mind) is moaning about as being early!!

But each to his own ideas of how to prolong the usable life of a Li-ion or in fact any chemistry battery !!!

I have not built a Li-ion charger myself (they are too cheap to worry about!), but being a camper, and having had problems with using car batteries in Caravans, over some years, I set out and built a charger of my own design, which has kept my caravan battery fit since I bought the battery in 2004.....

This is how my interest was spiked in batteries generally. But that is of course a wildly different chemistry!! Little of that relates to modern batteries!!

Except, treat them nice and they last longer....

But having laptops, with most of the recent ones having Li-ion batteries, I have also managed to extend the life of the battery of the laptop (Toshiba i7 well over 4 years old) as well!!

Its not difficult, anyone who wishes could understand the method, but it takes a good many years to actually prove the point to my own satisfaction.

But I have managed to help other people with laptops with batteries, to also extend the life well beyond average....some were needing a new battery within 12 months of purchase!!

But as I said before, please all continue to believe what you want to believe!!

Regards to all for 2019

Andy

 

[Benjahmin]

My Ezee battery is now four years old. 7500 miles on it, 309 charge cycles (I keep a diary) and all of them partial. Charger supplied is 4Amp with a fan, often left on well past the green light coming on. As far as I know the battery is pouch cells.
Laptop is an HP 8 years old and still on original battery.
I also have a secret charging method - I plug them in!

 

[flecc]

According to Bosch the charger only fires up to give a top up to cover natural drain and then goes off again ad nauseum...

Although I disagree with Andy on some of what he has posted about batteries, it is precisely this that he rightly complains of.

The point of greatest stress to cells is as they reach full charge and that is the same for the original charge or subsequent topping up of reducing content. Unplugging the charger to prevent it intermittently topping up very small losses avoids those unnecessary repeats of maximum cell stress.
.

 

[georgehenry]

With my cheap Chinese charger I just use one of these to limit how long the charge stays on.
https://www.amazon.co.uk/gp/product/B005C9S0I8/ref=ppx_yo_dt_b_asin_title_o06__o00_s00?ie=UTF8&psc=1

 

[Sturmey]

There is also a suggestion that a bike be not used immediately after charging.e.g. https://www.energuide.be/en/questions-answers/how-long-does-the-battery-of-my-electric-bike-last/1782/
There is (imo) some additional merits to this. If you look at the specs of many BMS', you will see that the balance current is somewhere around 50-80mA and the voltage is 4.2 volts. (The balance load resistors are low wattage).
Now, balancing takes place only after the cell voltages reach 4.2 volts and is slow (e.g 50-80mA), hence a certain amount of balancing still takes place, even after the light has turned green and the charger is pluged out.
If the cells are unbalanced and you use your bike immediately after charging, you immediately drop the voltage of the battery (and of the high cells) and deprive the balance circuits the opportunity to bleed down any remaining high cells.

 

[Nealh]

The balance does depend at the voltage the Bms is set for, my Swizzbee Bms balances at 4.15v others I have 3s, 7s & 10s vary and balance is between 4.16 -4-18v.

Though smart Bms can be programmed they are way more expensive and need a smart phone to monitor info, it's about time China programmers got their act together and started to incorporate max 4.1 - 4.12v balancing for better cell life.

 

[flecc]

it's about time China programmers got their act together and started to incorporate max 4.1 - 4.12v balancing for better cell life.

I suppose we in the e-bike field haven't helped with our constant calls for more range. The cells could last much longer with cutoff changes at both ends and sacrificing a little range.
.

 

[Nealh]

I modded/adjusted my basic Sans charger quite easily will post on new thread.

 

[georgehenry]

Flecc I think you are right and that for battery longevity a management system that allowed some choice or customization by the owner could be a way forward.

On a regular commute like mine I use no more than 45% and as little as 25% of my batteries capacity for each single leg of the journey, charging the battery back up at work.

A battery management system and/or charger that allowed you to adjust how much your battery was charged for maximum battery longevity, say 85% of its maximum capacity and a limit below which it was not allowed to discharge say 15% or whatever figures were optimum might increase the longevity of a battery by some margin and work very well for regular journeys that only use about half or less of the batteries capacity.

You would need to be able to over ride such a system when you wanted to use all the range possible or adjust the parameters to suit your own needs.

This need not need to be too complex with maybe just two settings, a maximum battery longevity setting with a reduced range and a maximum range setting to use all the batteries capacity.

I think Tesla cars uses something like this.

 

[georgehenry]

Yesterday was my coldest commute of the winter so far. Used 35% of the battery on my 14 mile off road route to work and 44% on my 10 mile road ride home at around midnight. BBC weather had predicted -3 for the ride home and my Yamaha LCD display showed -1 when I put the bike in my garage. It was around 8 degrees for my ride to work.