Battery question

Wsmith8007

Finding my (electric) wheels
Jun 23, 2020
7
2
Hi i took my samebike lv20 out the other way to check distance it did 18miles with pedal assist some hills but not really steep from a full charge the manual says its supposed to achieve double that i know its not going to do 30miles on one charge but 18 / 20 miles dos.nt seem enough so my question is am i still using battery power when the ignition key is on but freewheeling or do i have to turn key off to save battery life it dos.nt answer this question anywhere on line cheers will
 

sjpt

Esteemed Pedelecer
Jun 8, 2018
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Winchester
It shouldn't use any power when freewheeling.

The 'up to' figures often quoted assume flat, fast tyres on a good road, no wind, light rider, and lowest level of assist. Real life figures with middling assist can be around 1/3 the 'up to', and less still will full assist.

Is it the 48v 10ah battery I see on some adverts? That should 30 miles on a charge on middling assist. It might be worth checking the wheels can spin freely; maladjusted brakes or bearings can easily go unnoticed on an ebike.
 
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Wsmith8007

Finding my (electric) wheels
Jun 23, 2020
7
2
It shouldn't use any power when freewheeling.

The 'up to' figures often quoted assume flat, fast tyres on a good road, no wind, light rider, and lowest level of assist. Real life figures with middling assist can be around 1/3 the 'up to', and less still will full assist.

Is it the 48v 10ah battery I see on some adverts? That should 30 miles on a charge on middling assist. It might be worth checking the wheels can spin freely; maladjusted brakes or bearings can easily go unnoticed on an ebike.
Spot on it is the 48v 10ah with throttle and theres no way that this bike does 20km on pure electric i noticed bike was squeaking whilst riding lifted front wheel and noticed it did nt spin at all i did the release brake trick and now its spinning fine i also pumped the tyres up they were 10psi under will these factors improve distance and by how much roughly i have ordered spare battery but will the weight of the second battery being carried on rack youse more power from origanal battery cheers
 
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Andy-Mat

Esteemed Pedelecer
Oct 26, 2018
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Spot on it is the 48v 10ah with throttle and theres no way that this bike does 20km on pure electric i noticed bike was squeaking whilst riding lifted front wheel and noticed it did nt spin at all i did the release brake trick and now its spinning fine i also pumped the tyres up they were 10psi under will these factors improve distance and by how much roughly i have ordered spare battery but will the weight of the second battery being carried on rack youse more power from origanal battery cheers
I bet you fixed it.
Flat tyres are especially notorious for range. IMO they were far too low on pressure (not knowing the tyre type!).
Pump them up to their allowed maximum... Wear safety goggles while doing that..
Warped disks are bad as wll as badly adjusted disk brakes and wheel bearings. Carefully lube up the things that need it!
Let us know how you get on after that.
Andy
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
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Basildon
The average Ebike uses about 4w of power when the controller is switched on, but not powering the motor. That's measured using a wattmeter. I don't know why it's so high as the 5v regulator is only giving out about 50mA to power the sensors and the CPU. The 12v regulator powers the mosfets and 5v regulator, but with the mosfets switched off, that can't be much. If you have a control panel, there will be some power going to it as well out of the 4w. On some bikes, the big resistor gets quite warm, so that must account for the bulk of it.
 

RossG

Esteemed Pedelecer
Feb 12, 2019
1,628
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I believe the circuits in ebike controllers are not really optimised for low quiescent current vfr, I suppose designers consider a big Li-ion battery is man enough to take the drain under no load regardless.
I think some enthusiasts have tinkered and changed component values to modify their circuits and lower said current drain.
 

Spudmurph80

Finding my (electric) wheels
May 15, 2020
6
0
63
Hi there
Im new here and just would like to ask I have a 48volt battery and a new Bafang 36 volt 500 watt mid drive motor and I was told I could fit both together and it would be fine as it would be just overvaulting and it would just produce a little more power, which I thought would be fine but I have an error on my screen 07H which is a over voting error, is there anything I can do to correct this issue or have I got a problem.
Hope you can give me advice and do apologise for just jumping in.
Cheers Kev
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
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There's no point in running a 36v mid motor at 48v unless you have a very high natural cadence because the cranks will spin 33% faster and if you pedal at normal speed, it'll run inefficiently.

I'm pretty sure that you need the 48v controller to run at 48v.

With a mid drive, if you need more power, you increase the current, not the voltage. if you want more speed, you change the gearing, bearing in mind the power you have.
 

Spudmurph80

Finding my (electric) wheels
May 15, 2020
6
0
63
Thanks for the info, I will have to order a 48volt controller to fit to the motor thats sounds like the best option, cheers
 

Wsmith8007

Finding my (electric) wheels
Jun 23, 2020
7
2
I bet you fixed it.
Flat tyres are especially notorious for range. IMO they were far too low on pressure (not knowing the tyre type!).
Pump them up to their allowed maximum... Wear safety goggles while doing that..
Warped disks are bad as wll as badly adjusted disk brakes and wheel bearings. Carefully lube up the things that need it!
Let us know how you get on after that.
Andy
Hi last question for a while when I charge my bike it goes from red to green for full charge but about 10mins later if I plug charger in it goes back to red is this normal or is my battery losing some of its charge
 

ChuckingFeet

Pedelecer
Dec 3, 2019
55
60
Derby
At a guess, you are taking your battery off charge a little early, it will take a while to balance the cells to the same voltage .this can take a few hours with a new battery .I have heard it said that to maximise battery life you should charge to 80-90% most of the time , but charge fully occasionally .
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
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Basildon
Hi last question for a while when I charge my bike it goes from red to green for full charge but about 10mins later if I plug charger in it goes back to red is this normal or is my battery losing some of its charge
That's completely normal. You're charger charges to 42.0v, then the balancing system will drain down any cells that are over say 4.17v to 4.17v. You have 10 cell-groups, so the total voltage would drain down to 41.7v. If you put the charger on again, it'll charge back up to 42v and the whole process will repeat. You're not gaining anything by putting your charger back on. all you're doing is heating the environment.
I have heard it said that to maximise battery life you should charge to 80-90% most of the time , but charge fully occasionally .
That's a complete myth spread by people that don't know what they're talking about and they don't understand the context of the facts that they are reading. There is some fact in the theory that's based on research on individual lithium cells from The Battery University website, but it's a very dodgy thing to do for normal ebike batteries because of the way they manage their cell balancing. The balancing doesn't complete in an occasional full charge. It's based on the principal of a little and often.
 
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Wsmith8007

Finding my (electric) wheels
Jun 23, 2020
7
2
That's completely normal. You're charger charges to 42.0v, then the balancing system will drain down any cells that are over say 4.17v to 4.17v. You have 10 cell-groups, so the total voltage would drain down to 41.7v. If you put the charger on again, it'll charge back up to 42v and the whole process will repeat. You're not gaining anything by putting your charger back on. all you're doing is heating the environment.

That's a complete myth spread by people that don't know what they're talking about and they don't understand the context of the facts that they are reading. There is some fact in the theory that's based on research on individual lithium cells from The Battery University website, but it's a very dodgy thing to do for normal ebike batteries because of the way they manage their cell balancing. The balancing doesn't complete in an occasional full charge. It's based on the principal of a little and often.
Cheers I thought I had a dodgy battery most appreciated
 

ChuckingFeet

Pedelecer
Dec 3, 2019
55
60
Derby
So, is it best just to fully charge ? My commute has now gone up to 40 km daily , so I need to charge every day, was a bit concerned about the effect on battery life.Same person also said my brake discs were installed the wrong way....
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
9,822
3,993
Basildon
So, is it best just to fully charge ? My commute has now gone up to 40 km daily , so I need to charge every day, was a bit concerned about the effect on battery life.Same person also said my brake discs were installed the wrong way....
You install discs with the markings facing outwards. We get weird people on here from time to time. They read stuff on the internet that they don't understand, probably because they don't have the intelligence to figure out the context of what's written, then they post their rubbish on here as if it's science.

For 40km per day, I'd charge every day until your charger light goes green. A full battery will always give you more power in whatever controller setting you have because the voltage is higher.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
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West Sx RH
So, is it best just to fully charge ? My commute has now gone up to 40 km daily , so I need to charge every day, was a bit concerned about the effect on battery life.Same person also said my brake discs were installed the wrong way....
Taking Andy- mat's advice is best taken with a large pinch of salt, we all had a chuckle at his disk brake thread and theories. He then went on to tell us how we had the rotors on the wrong way round.

Charging fully isn't going to cause issues when you are doing that mileage daily.
 

Andy-Mat

Esteemed Pedelecer
Oct 26, 2018
2,214
562
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Taking Andy- mat's advice is best taken with a large pinch of salt, we all had a chuckle at his disk brake thread and theories. He then went on to tell us how we had the rotors on the wrong way round.

Charging fully isn't going to cause issues when you are doing that mileage daily.
I have to laugh at such comments, as none of you have actually tried this out, or spoken with an engineer, particularly one who works with metal under high temperatures, as he would explain why its worth trying!
My experience is that it prevents disk burn/overheating, disk chatter and misshapen disks when they get really hot......even on bikes where such damage has previously occurred, or even when very heavy usage of the disk brakes is regularly required.
But, "you can lead a horse to water, but you can't make him drink!"
Naturally its a free choice, but I had expected that at least one person would be adventurious and brave enough, to try and prove me wrong!
But apparently nobody is brave enough!!
But thanks for the laugh!
Andy
 

vfr400

Esteemed Pedelecer
Jun 12, 2011
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Basildon
I have to laugh at such comments, as none of you have actually tried this out, or spoken with an engineer, particularly one who works with metal under high temperatures, as he would explain why its worth trying!
My experience is that it prevents disk burn/overheating, disk chatter and misshapen disks when they get really hot......even on bikes where such damage has previously occurred, or even when very heavy usage of the disk brakes is regularly required.
But, "you can lead a horse to water, but you can't make him drink!"
Naturally its a free choice, but I had expected that at least one person would be adventurious and brave enough, to try and prove me wrong!
But apparently nobody is brave enough!!
But thanks for the laugh!
Andy
That's weird because I've had my discs on the right way for 6 years and they haven't worn, distorted or got burnt, despite going down massive hills regularly and carrying my bulk, plus shopping to.

Hmmm! You got it from an engineer who works with metals under high temperatures? Now it all makes sense why you say what you do. In case you didn't know, heat rises. You're supposed to put your frying pan over the heat when you do your fried eggs, not under it.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
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We aren't brave enough because we're not so stupid to try it in the first place.
 
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