Best ways to charge and maintain battery life

[Chobbit]

Hi,

So I have a pretty standard Halfords Carrera Vengence e-mountain bike as my first e-bike. Had it almost a year but after 6 months of about 75-120 miles a week usage the battery had halved in life performance and would only give me about 60% the power it gave me in each power mode but was still using much more battery than a couple of months earlier.

Now I know battery life decreases over time but I expected a year of use before it was noticable, Halfords took it in and sent it off for investigation. It came back that the battery wasn't working correctly however they said I've also not been charging it correctly.

At first I started off with the battery using full power mode all the way as I hadn't rode a bike in 18 years and I was doing 26 miles as an asthematic so needed the help, this would use 4/5 battery bars each way too and from work so I would charge it for 8 hours at work and also over night when I got home. After a few weeks I settled at medium power but this would still use over half a better 3/5 bars each way so I still charged it the same as before as I didn't want to run out of charge on a journey.

Anyway even though the light on the power supply changes from red (charging) to green (charged and no longer charging) they told me I should never do it over night as I need to take it off as soon as the green light comes on and it's fully charged (about 6 hours).

So when I got the new battery I decided to put it on the lowest power setting and with the new battery this was using 3/5 bars to get me too and from work so I wouldn't charge it at home and instead only charge it at work where i could keep an eye on it and take it off charge when the green light came on.

However after 4 months of doing this Its started using 5/5 bars (last bar is flashing to say its about to run out of power and now after 6 months the new battery is still giving me the same power as when new but doesnt last a full 26 mile round journey on the lowest setting (when its meant to last 45 miles) so I have to charge it twice a day again (at work and at home).

I read up that lithium batteries are supposed to last longer by charging them more often when they are at 50% empty rather than charging them from 90% or 100% empty unlike Halfords recommended. However neither method seems to have gave me more than 6 months before the life has drastically reduced.

So what advice can you give to help prolong the batteries? and is it bad to charge a battery overnight where it will be on charge longer than it takes to fully charge? As at this rate I'll need a new battery every 6 months and at £300 each, £600 a year is more than it costs to Mot, Service and Tax my car a year :/

 

[Wicky]

There''a quite a few threads on the best charging regime to follow if you use keywords battery charging in the search bar

This one for example > http://www.pedelecs.co.uk/forum/threads/battery-charging.27591/

 

[anotherkiwi]

1. Use a battery with quality cells inside
2. Use a battery that has sufficient discharge rate for your requirements - full power requires cells capable of 10 to 15 Amp discharge.

There was nothing wrong with you charging your battery twice a day and overnight, the charger stops charging when the BMS tells it the battery is full. Or it may continue trickle charging and balancing the cell groups.

 

[wheeliepete]

As AK says, nothing wrong with your charging regime. It would be interesting to know what cells are in those battery packs on the Carrera bikes, as by your experience, it would seem they are not the best. Anybody opened one? Maybe Jimmy (Insat inc.) would know.

 

[Chobbit]

Thanks for the replies I know nothing about batteries but I knew there was no issues with charging overnight as like mobiles you charge them overnight and. There fine,it takes a year or 2 before the battery degrades.

For £300 you would hope they were good however I'm not confident and the fact that Halfords advice with battery charging doesn't seem to have helped increase the life of the battery the second time doesn't give me confidence in there advice either.

Can you buy a different battery and different battery holder on the bike to replace the one it came with? And what would you recommend?

 

[Chobbit]

Thanks also Wicky for the thread suggestion i just did the 10 second button check and i have 4/5 lights showing which suggests its still at 80-90% health at least.



Should using a lower power mode mean the battery should have a longer life than if you used the higer power modes or does that only make a difference with power drain?

 

[wheeliepete]

There have been quite a few threads on here regarding replacement batteries on Carrera bikes for various reasons. It would be worth giving Jimmy a call as he may have some insight on this. He builds and re-cells lots of battery packs and is very knowledgeable. He deff. knows his stuff.

 

[Chobbit]

Thanks which Jimmy am I looking for?

 

[wheeliepete]

Should using a lower power mode mean the battery should have a longer life than if you used the higer power modes or does that only make a difference with power drain?

It all depends on the cells that are in the battery pack. If they have a reasonable discharge rate, say 10 amp+, then using full power will be fine, but if lower rate, 5 amp, then they will be working harder at full power and will deteriorate faster.

 

[wheeliepete]

Thanks which Jimmy am I looking for?

https://ebikebatteries.co.uk/

 

[Nealh]

Tonkin along in high assist will draw max amps and doubt that the cells employed inside the battery are really up to it.

My old Oxydrive batteries used Samsung cells but only the very poor mediocre 22 & 26F 4.4/5.2a cells, they lasted for about 18months each before I saw capacity reduced by a bout 30%.
The 22F now only give about 50% range and are past it really but ok for a get me home reserve if taken along.
The 26F were better & was broken up to make 2 x 6p3s 12v packs which I run in series with my 2 x36v PF packs.

 

[Benjahmin]

I don't think you've done anything wrong Chobit. The information given by Halfords staff is probably what they've been told to say. They probably have as much knowledge about batteries as you do.
Certainly using max. power setting consistantly will shorten the battery life, as higher current draw is needed. I suspect that the cells in the battery will have been specced (at best) to deliver medium current as a constant, and full assist current in short bursts only. Until someone opens a pack, we won't know what's in there.

 

[Chobbit]

Thanks I'm looking and the Bosch 500 seems like it's getting good reviews, hopefully should handle the power and life better. Just need to find out if it will fit in the same place and how hard it is to replace with next too no knowlege lol

 

[wheeliepete]

You won't be able to fit a Bosch battery onto your bike, they will only work with a Bosch motor. Have you spoken to Jimmy?

 

[Chobbit]

I've sent an email to the email address info@ebikebatteries.co.uk on that site you mentioned.

Will that work? or is he on the forum too to get hold of?

 

[wheeliepete]

He is on the forum, but dosn't post that often. He is very approachable and will happily chat on the phone about batteries prob. for longer than you want toIt would be worth asking him if he has worked on any of the Suntour system batteries and if so, what cells they contain, as this may give you an insight into your problems. I also strongly suspect that the BMS is at the root of the cutout problems that many Crossfire owners have experienced.