Battery not charging but now it is

[jedd]

Hi again
As a newbie to electric bikes I apologize for the 20 questions but here goes again .
Just last week I inherited an Ebike to which is only a few months old and has barely covered 70 miles.
I've been enjoying it immensely this week cycling along the quiet country lanes and the unusual decent weather of late.
The bike itself came with two 48v 13 ah battery's.
The reason for this was that the original battery that came with the bike would not charge ,and the company just sent a replacement battery and never asked for the original back.
The issue with the battery was that when it was plugged in, to be recharged the charger indicator light would go straight to green.
Curiosity has got the better of me today and thought I would try and see if I could coax it into charging.
To my surprise after a few attempts of plugging it in with no success the charger light went red for a minute then to green.The next time I tried it ,its now charging up just fine.
I'm naturally very suspicious of lithium batteries and the potential dangers on them, so it's sat outside as I type this whilst on charge.
Any ideas what could of been the issue and more to the point have I solved it and is it safe.
Back to my bike, that's all I can say is wow.
I've done 130 miles on it this week, and its been fantastic.Im not a young guy anymore and its been getting increasingly more difficult to get out and enjoy my conventional road bike with bad hips and knees to contend with.I would get home from a 40 mile ride and would hardly be able to get down the stairs the next day from the pain.As you can imagine it's slowly put me off using it.
I've always been an outdoor type and have worked outdoors all my life and hate being inside.
Not being able to get out there on a bike and unwind doesn't do me any favours mentally and can feel my mental wellbeing take a steep nose dive when I'm stuck indoors during nothing.
This Ebike has really opened up the world again and I've managed to get some decent miles in again without feeling the pain.
It feels like all my Christmas have come all at once.A free Ebike and two working batteries (hopefully).
All the very best

 

[Deleted member 16246]

Congratulations on seemingly getting two batteries for the price of one!

Sometimes batteries (or the BMS) go into a sleep mode if left alone unused. Maybe this might account for the reluctance of the original battery to charge up. My partner bought a second hand, mint, Pendleton ladies e-bike sold cheap (£350) with a duff battery. The battery had been left for several months over winter uncharged and when we got it, it would not charge at all according to the seller.

I got it to work and it has worked brilliantly ever since. I did it by VERY CAREFULLY and briefly charging it on its output pins. This should not really be done and CERTAINLY not by anyone unfamiliar with the hazards or without a multi meter, or for any length of time. I just needed ten minutes of that to wake the damned thing up.

The problem and danger with this is that there is no charge voltage protection and talking about it as a technique might lead to some numpty putting his battery on charge on the output and leaving like that and causing a fire. I watched it like a hawk for ten minutes and monitored the voltage on the output pins. It started low and rapidly came up to about 32 volts (36 volt battery) and then i disconnected it and used the proper, safe charging port. That battery can even now, two years later take her 25 miles.

I hope yours continues to work well. As for safety - well we all know about and have seen fires caused by lithium batteries. I think most of them are likely caused by damage / abuse and using the wrong chargers. A decent charger will cut off at the sensible max charge voltage and the BMS should prevent it going any higher even if the charger max voltage protection fails in the charger unit.

That said. Don't put it on charge and go to the pub or bed, or leave it charging in the kitchen while you are away on holiday.

I never leave mine alone when it is charging and I certainly wouldn't go to bed and leave it on charge.

 

[jedd]

Thanks for taking time to reply.
It's been on charge now for around 3 /4 hours in the back garden and all appears to be well.The charger is just very slightly warm and the battery is cold to the touch.Its reached about 3 quarters charge so I've now switched it off as I've got to go out and get some shopping.
Once back home I will pop it back on charge again and hopefully all will be well

 

[Deleted member 16246]

Sounds like a winner then Jed - as long as it will run the bike for a typical range.

When you put it back on charge, don't be frightened to leave it a few hours connected up and on the green light. Don't do that all the time, just now and then. This occasional treatment allows the BMS to balance the different cell groups so you get all of them to the same voltage. Supervise it of course.

 

[jedd]

Thanks for the good advice Tony.Its now got a full charge according to the led lights on the battery but the charger is still running,so I'm half expecting it to turn green and switch itself off shortly.
Tomorrow I will take it for a short ride just to see if it's got the same range as the good battery.
Glad it's been a dry day so that I could charge it up in the safety of the garden and not inside the house.

 

[jedd]

I went out for a ride out today and tested the battery that initially wouldn't charge.I tackled some steep climbs to put it (and me) through its paces.
I got around 34 miles out of it before it dropped to 20%.
Luckily I took my other battery as well just Incase I was left stranded. Last night I had a brainwave as to how to carry it.
I have a bike specific backpack which is very narrow and the spare battery fitted perfectly nice and tight with plenty of foam padding around it.
The battery was not as long lasting as the other, but I'm hoping after a few recharge cycles it will improve (time will tell)
So overall today I did 56 very enjoyable miles over the two batteries and still plenty more miles left in the second battery.

 

[Deleted member 16246]

If I was riding my converted ebike for 56 miles, I would not feel great in the lower regions. You must have a much better seat than I have. So it looks like the previously bad battery has a greater range than its replacement.... Did I get that right? Well that's a success and no mistake. I expect with a bit of use and a balance charge (leave it on charge for a few hours withe the green light on) the now less good battery will be as good as the other one. You can be pleased at what has been achieved there. I would be, and great that with the combined batteries, you can get such a good range.

 

[jedd]

It's good having an extra battery and I'm really pleased I've managed to breath some life into to the original one.
I've been a keen cyclist for many years now and have done a few century rides across Wales, but a couple of years back my heath took a turn for the worst(just general old age stuff really)
I still tried to get out there and soak up the miles,but in all honesty it was really starting to hurt me and by the next day I was good for nothing.Conventual cycling was slowly becoming a chore as to enjoyment.
As a stroke of luck and kind heartedness this bike was gifted to me, and all though I was emensely grateful I was not convinced it was the right way to go.
Before I got it I was full of negativity towards it and that it would not be for me.
As the old fart I am i tend to not like changes in life and was very suspicious about the safety aspects of the battery, as well as range anxiety ,and not being familiar of how to fix or diagnose potential problems with Ebikes.
Well to be honest I was instantly sold on it after the first few miles of riding it.
The thought of slogging my way along on fat bike tyres just horrified me after doing many thousands of miles on low rolling resistance skinny road bike tyres.
But as soon as I turned the crank arm and felt the assistance kick in I was hooked.The lanes were I live are very isolated and in very poor condition.This bike just swallows up everything the roads can through at it ,and at the same time feels rock solid and not twitchy.Now that I've got a spare battery that I can take with me it has also put my range anxiety to rest.
As for the complexity of it I'm finding the mechanical side of this bike to be much more simplistic than my all bells and whistles road bike.The gears on it are just a simple 7 speed affair instead of the electronic gears on the road bike.
The only thing that still evades me is the electrical side of things, but with plenty of reading I'm slowly getting to grips with it all.
Today I did the 50 something miles but it was a complety different experience as to doing that on the road bike.
On the road bike I would of been pushing hard trying to keep aero and manage my energy levels ,mainly reading the road a few metres ahead.With the Ebike I was pushing on more or less the same pace, but because it was easier I started to take in the fantastic views of Wales (does that make any sense).
I came back home today after doing some half decent miles and achieving some good average speeds and feeling fresh and not hurting.
With an Ebike you can dictate how much energy you want to contribute to the ride as opposed to the climbs/headwinds dictating to you on a conventional bike.
A big thumbs up from me so far

 

[Deleted member 16246]

Sounds like the perfect marriage this.

It's good having an extra battery and I'm really pleased I've managed to breath some life into to the original one.
I've been a keen cyclist for many years now and have done a few century rides across Wales, but a couple of years back my heath took a turn for the worst(just general old age stuff really)
I still tried to get out there and soak up the miles,but in all honesty it was really starting to hurt me and by the next day I was good for nothing.Conventual cycling was slowly becoming a chore as to enjoyment.
As a stroke of luck and kind heartedness this bike was gifted to me, and all though I was emensely grateful I was not convinced it was the right way to go.
Before I got it I was full of negativity towards it and that it would not be for me.
As the old fart I am i tend to not like changes in life and was very suspicious about the safety aspects of the battery, as well as range anxiety ,and not being familiar of how to fix or diagnose potential problems with Ebikes.
Well to be honest I was instantly sold on it after the first few miles of riding it.
The thought of slogging my way along on fat bike tyres just horrified me after doing many thousands of miles on low rolling resistance skinny road bike tyres.
But as soon as I turned the crank arm and felt the assistance kick in I was hooked.The lanes were I live are very isolated and in very poor condition.This bike just swallows up everything the roads can through at it ,and at the same time feels rock solid and not twitchy.Now that I've got a spare battery that I can take with me it has also put my range anxiety to rest.
As for the complexity of it I'm finding the mechanical side of this bike to be much more simplistic than my all bells and whistles road bike.The gears on it are just a simple 7 speed affair instead of the electronic gears on the road bike.
The only thing that still evades me is the electrical side of things, but with plenty of reading I'm slowly getting to grips with it all.
Today I did the 50 something miles but it was a complety different experience as to doing that on the road bike.
On the road bike I would of been pushing hard trying to keep aero and manage my energy levels ,mainly reading the road a few metres ahead.With the Ebike I was pushing on more or less the same pace, but because it was easier I started to take in the fantastic views of Wales (does that make any sense).
I came back home today after doing some half decent miles and achieving some good average speeds and feeling fresh and not hurting.
With an Ebike you can dictate how much energy you want to contribute to the ride as opposed to the climbs/headwinds dictating to you on a conventional bike.
A big thumbs up from me so far

Sounds like a perfect arrangement for you. I know what you mean about the revelation of the bike's ease of riding after powering along on a traditional bike. I have a lot of hills around here and when I moved here from a flatter place, the bikes I brought with me were pretty awful on the hills. Not anymore....

Maybe if you want to take two batteries with you for range, you could explore some sort of rack mounted box with padding inside so you could carry the spare comfortably rather than on your back.

One thing though - don't be tempted to connect two batteries up with their output in parallel unless you REALLY know about the safety issues of doing that. If they are at the same voltage you can create very large currents from one more charged battery into the one with a lower state of charge. It can cause damage and fires. What you are doing in replacing a discharged battery is of course perfectly safe.

 

[jedd]

Great advice and thanks for taking the time to share it out.

 

[jedd]

I little bit of an update on my spare battery.
I've had a few rides out on it now and the range has slowly increased with each charge.My first outing on it returned around 34 miles before the battery hit around 20% but its slowly increased to around 46 miles.Im putting this down to it being a new battery (alas originally not wanting to charge) and that there is a breaking in period with them.
I thought I had managed to get a reliable spare battery but last night after another 55 mile ride it refused to charge again.I tried plugging and unplugging it to no success (just the green light would illuminate)
I kept tinkering around and I put the battery back on the bike, flicked the switch to "on" on the battery and powered up the bike.Switched everything off again and when I went to to recharge the battery again it worked!!
I left it for an hour to do it's thing then switch it off as I had to go out for a few hours.
When I returned home I connected it again to the
charger, switched it on and it wouldn't charge again,grrrrr.
I gave up after that and called it a day.
Thinking about things today and after abit of internet reading on the problem I came across a comment on another Ebike forum suggesting to flick the switch on the bottle type battery and then try and charge it.
This evening I've just tried exactly this and it's now charging up merrily away .
I haven't a clue why doing this would make any difference.

 

[saneagle]

The most likely cause is a burnt charge socket, which happens when you plug in the charger when it's switched off.

It could also be a dodgy connection between the charge socket and the BMS or fuse inside the battery.

Either way, you need to open the battery, and when it won't charge, use a meter to follow the voltage from the charger, through the charge socket and all the way to the BMS to see where it's interrupted.