To be honest, if the on/off-charge voltage delta is only 0.3V (0.03V/cell), you don't need to worry about it.
Basic Sans charger mods/adjustments.
- Thread starter Nealh
- Start date
Sorry to insist but you really should be aiming for 41v, that is closer to 85% capacity than 40v. Look at that discharge curve I posted again.
No problem at all, I'm here to learn.
There seems to be a general consensus that charging to 80% is good for many cycles. I can do my commute no problem between 36-40v so I don't see the downside. Also I have Chinese cells from yosepower, which might look a little different.
What kind of gain do you mean I'll get by charging to 41v instead?
When we are on the subject of being sceptical of "things I read in forums". I'm charging my battery indoors at 20 degrees Celsius since I read somewhere that charging in the cold is a bad thing. I have 5 degrees in the shed, could I just as well charge there and not remove the battery from the bike?
There seems to be a general consensus that charging to 80% is good for many cycles. I can do my commute no problem between 36-40v so I don't see the downside. Also I have Chinese cells from yosepower, which might look a little different.
What kind of gain do you mean I'll get by charging to 41v instead?
When we are on the subject of being sceptical of "things I read in forums". I'm charging my battery indoors at 20 degrees Celsius since I read somewhere that charging in the cold is a bad thing. I have 5 degrees in the shed, could I just as well charge there and not remove the battery from the bike?
Talking of voltages and charging times, you would think these so called 'Smart' batteries would be able to sort all that out for themselves and not just guzzle current until they've filled their boots and ready to pop.
I mean if you think about it they can cost as much as £500 and have a limited life cycle with no resell value whatsoever. Consider also whatever brand name is stamped on the side of the case the cells contained within are almost certainly of Chinese origin and manufactured for pennies.
I would estimate an average E-bike battery costs no more than £20 to produce, and if that sound fanciful I came across a company yesterday in China selling Bafang hub motors for twenty quid if you buy in bulk....and they still make a fortune!
I mean if you think about it they can cost as much as £500 and have a limited life cycle with no resell value whatsoever. Consider also whatever brand name is stamped on the side of the case the cells contained within are almost certainly of Chinese origin and manufactured for pennies.
I would estimate an average E-bike battery costs no more than £20 to produce, and if that sound fanciful I came across a company yesterday in China selling Bafang hub motors for twenty quid if you buy in bulk....and they still make a fortune!
Where did you get that from? Let's see if I can enlighten you a bit.
It's a matter of safety that lithium batteries have a management system in them to look after both charging and discharging. These things have been developed over many years and the manufacturers go to a lot of trouble to make sure that they're optimised for everything you need from the battery.
All the batteries that I've repaired had a management system in them. I've never heard of or seen a lithium battery that didn't have such a system apart from some home made ones that guys either made themselves or bought from Ebay because they were cheap.
Can anybody can show me evidence that a single battery from a UK electric bike lasted longer than what's normal by using a charging procedure outside of the manufacturers recommendations? I can show you a few examples where they lasted a lot less!
Last edited:
A lot of fakes in/from China, a Bafang hubfor £20 in bulk hmmmm.
How about alink so we can see for ourselves.
How about alink so we can see for ourselves.
@ vfr400.. Well I wasn't talking about BMS itself, as you say that's built into all e-bike batteries we would hope.
I'm thinking more of Nealh and his excellent advice on controlling battery charge voltage, I believe it's sound and correct.
I've been using similar methods of voltage/current control on lithium camera batteries for many years, and I believe it's because of that I'm still using batteries that are in some cases as much as 10 years old.
Their ability to hold a charge has diminished over the years somewhat of course but still plenty of life left in them.
Incidentally, I have some Sanyo Ni-Cads that are over twenty years old and still going strong !
@Nealh...Ah the Chinese, been doing business with them for years. Ali-x, DH, Bangood know em all. Used to buy Fit Bit clones for a fiver each and sell them for 35 quid on flea bay, happy days...
You have to remember £1 here is worth a lot more in China but as you say watch out for fakes. The problem is you have to buy in large quantities to get items so cheap, then you end up paying import duties so bang goes your profit. There are ways around that of course but perhaps I'd better leave that subject for another thread.
I'm thinking more of Nealh and his excellent advice on controlling battery charge voltage, I believe it's sound and correct.
I've been using similar methods of voltage/current control on lithium camera batteries for many years, and I believe it's because of that I'm still using batteries that are in some cases as much as 10 years old.
Their ability to hold a charge has diminished over the years somewhat of course but still plenty of life left in them.
Incidentally, I have some Sanyo Ni-Cads that are over twenty years old and still going strong !
@Nealh...Ah the Chinese, been doing business with them for years. Ali-x, DH, Bangood know em all. Used to buy Fit Bit clones for a fiver each and sell them for 35 quid on flea bay, happy days...
You have to remember £1 here is worth a lot more in China but as you say watch out for fakes. The problem is you have to buy in large quantities to get items so cheap, then you end up paying import duties so bang goes your profit. There are ways around that of course but perhaps I'd better leave that subject for another thread.
Even more expensive now due to Bosch and the EU consortiums resorting to closing out any competition.
The Swizzbee is a good 13 years old now ( was 2.5 - 3k euros) and the electronics are LG made by Dreifels Ag, the pair will have extensively done the numbers game and the BMS is set for 41.5v per cell for max balance. With thoughts on cell longevity without compromise on range as range is what the buyer wants the most.
The original li -poly was scrapped two years ago.
The original li -poly was scrapped two years ago.
Last edited:
I have a Sony Handycam that I bought in 1999, so 20 years old. It too uses lithium batteries and they still work. I only used the standard charger and charging procedure but during that time, I always wore the same Casio watch on my wrist, so if you want to extend the life of your batteries further, you could think of trying the same.
Let's try and make this clear. There's cause and effect. Two statements can be true, but it doesn't mean that they're related. Only by doing tests according to scientific principles can you draw conclusions.
Do you remember at school when you did experiments and you had to make two headings "experiment" and "control", then you did two experiments, one to show that the liquid turned blue when you added the chemical and another to show that it stayed clear when you didn’t so you could draw the logical conclusion that the chemical turned the liquid blue. Without the experiment where you didn’t add the chemical, you would never know if the liquid was going to turn blue on its own.
Coming back to the point. We have some guys on this forum who's batteries have lasred a very long time using the standard charger and charging procedure and others who's batteries expired very quickly, so we can reasonably deduce that there are factors that affect battery life, though we don't know how many factors there are and how significant they are. For data from anybody that tried non-standard charging procedures, all we have are a few anecdotes. Not a single one has taken their battery to the end of it's life nor compared a battery's decline with a similar one that had standard charging under the same usage conditions.
If anyone is interested, there's some good reading here on how to draw conclusions from statistics.
https://www.google.com/url?sa=t&source=web&rct=j&url=https://uca.edu/psychology/files/2013/08/Ch10-Experimental-Design_Statistical-Analysis-of-Data.pdf&ved=2ahUKEwium4nKncrgAhVDRxUIHZ7ZDeQQFjAAegQIAxAB&usg=AOvVaw15gZHKd6ciwZkIzuwkXTZH&cshid=1550663255779
I'm not disagreeing with the data and tests done by the Battery University, though I have many questions about which cells they tested and whether they were the lastest much improved ones that we have in our batteries now. Their test were done on cells that didn’t have a typical ebike management system. To draw any conclusion, they'd have to redo the tests that included them, then look at all the outcomes and failure modes.
Last edited:
For the most part I would agree you but would take issue with you on one thing. I'd suggest we do know how many factors affect battery life and their significance.
I haven't read every thread that exists on these forums, but I can take you word for it that know one has carried out a full and scientific test on their batteries over an extended period of time. But there again they wouldn't have to, it's already been done many times before by the manufacturers that's what they release spec sheets for.
Of course you can always do what one poster said earlier in this thread, namely buy a battery use it and when it's done get another !
I haven't read every thread that exists on these forums, but I can take you word for it that know one has carried out a full and scientific test on their batteries over an extended period of time. But there again they wouldn't have to, it's already been done many times before by the manufacturers that's what they release spec sheets for.
Of course you can always do what one poster said earlier in this thread, namely buy a battery use it and when it's done get another !
That's right, but we only see manufacturers tests on individual cells and under specific conditions. I've never seen any life cycle tests done on compete batteries, where there are a large number of extra failure modes, and operating conditions are cosiderably more variable.
Tesla charges cells to 4.15v, they might know a thing or two? That would be for Sanyo NCR/Panasonic cells which they make.
And I even recall this tweet from Elon Musk who have joined this discussion numerous times:
One should mention that he in another tweet states that going below 80% isn't worth it even though some research indicates 70% is best of the best and even 90% is "still fine" as he puts it.
What happens in a Tesla car has very little relevance to a typical electric bike because they have completely different management systems and operating characteristics.
This is thec big problem, that people take things from one context and apply them to a different one and expect them to work the same. We're talking about batteries here, not cells.
This is thec big problem, that people take things from one context and apply them to a different one and expect them to work the same. We're talking about batteries here, not cells.
As I see it there are several problems with battery tests. As you say test are usually carried out on individual cells only and not as a complete rechargeable power unit. Then there's manufacturers brand, who makes what for whom?
I have a Panasonic battery in my bike, well it's supposed to be that brand only I happen to know the cells inside are LG's. So that poses the question who makes LG battery cells, the company themselves or are they outsourced.
Manufacturer's advice is of no use if the cells inside a battery are made by someone else.
I am also of the belief that whoever claims to build a particular battery the cells inside are more often than not mass produced in China.
That's not to say they will explode or degrade any quicker for it, it's just we should all bear in mind because an item carries a well known brand name does not mean they manufactured it themselves.
You can wear a t-shirt with 'CocaCola' printed on it, that doesn't make you a can of fizzy pop!
I have a Panasonic battery in my bike, well it's supposed to be that brand only I happen to know the cells inside are LG's. So that poses the question who makes LG battery cells, the company themselves or are they outsourced.
Manufacturer's advice is of no use if the cells inside a battery are made by someone else.
I am also of the belief that whoever claims to build a particular battery the cells inside are more often than not mass produced in China.
That's not to say they will explode or degrade any quicker for it, it's just we should all bear in mind because an item carries a well known brand name does not mean they manufactured it themselves.
You can wear a t-shirt with 'CocaCola' printed on it, that doesn't make you a can of fizzy pop!
That's the million dollar question. The advice I would give if you haven't opened up your battery and know which sort of management system it has and how it works, is as follows.So to summarize, what would be the best method to charge your eBike battery?
1. Use the charger supplied with the bike and always charge it to full.
2. Don't leave the charger on for hours after it's gone green.
3. Don't keep topping up your battery when you don't go far.
4. Don't run your battery to minimum unless you need to.
5. Don't leave the battery uncharged for very long when it's run right down.
Had to agree with all vfr's suggestions on battery care and here's a couple more for consideration.
6. keep your battery in cool storage conditions, but charge at room temperature.
7. Don't charge your battery to full and leave it unused for long periods of time.
You may also want to check the following.
1. Make sure the material connecting the cells in your battery are pure nickel and not nickel plated steel and of equal length to ensure even current flow and reduce power loss through heat.
2. Ensure the main power take off wires on the pack are connected to all of the last group of cells and not just one, so as to keep the load even and not put unnecessary strain on one cell leading to premuture ageing and failure.
I am only adding these to show that any charging regime you may adopt will be futile if your battery is poorly constructed.
6. keep your battery in cool storage conditions, but charge at room temperature.
7. Don't charge your battery to full and leave it unused for long periods of time.
You may also want to check the following.
1. Make sure the material connecting the cells in your battery are pure nickel and not nickel plated steel and of equal length to ensure even current flow and reduce power loss through heat.
2. Ensure the main power take off wires on the pack are connected to all of the last group of cells and not just one, so as to keep the load even and not put unnecessary strain on one cell leading to premuture ageing and failure.
I am only adding these to show that any charging regime you may adopt will be futile if your battery is poorly constructed.