Lipo battery loosing charge range

Arakasy
Posts: 74
Joined: Tue Jul 15, 2014 8:21 am

Lipo battery loosing charge range

Postby Arakasy » Thu Nov 05, 2015 8:20 am

Hi guys, I've got a small bafang crank drive... Damn thing is legendary however the battery is starting to loose its range.. Started out as an 20ah, over the last few months it's been dropping the amount of Ah I can pull... Last night it died after only 8.9 Ah used (as measured by the cycle analyst pro). (This is my fathers battery)

I have the same setup but purchased my battery from emev... Was rated at 22 Ah when I received it.... I'm actually yet to see my battery run out (and I've tried)

So we have two Lipo batteries, one from a guy in Brisbane ( the one on its last legs) and we have one sent in from China that goes so strong it's like I'm the energizer bunny. Both get the same usage rates... Both pushes a trike up to above 30 kph, I even cart my dog along behind me in a trailer....we ride together, so it's not that the bad battery gets more use.

Can anyone recommend how to breath new life into dads battery, I'm going to order him a brand new battery from emev for Christmas, but he is scared to ride his trike until it arrives... He is disabled and can't peddle (I have to swap him over to my trike and push his home......over it...please help :mrgreen: cause new batteries are damn expensive and if I can macguiver my ass outta this issue I would love it much.

Ps... If you want to see the trikes we ride ill drop a picture when I get to my phone if anyone asks for a look see :mrgreen:
Don't Panic
And I don't know
Ride casual... Not to casual
They might snap out it's comfortable !!

cj7hawk
Posts: 1143
Joined: Sun Jan 18, 2015 9:00 pm

Re: Lipo battery loosing charge range

Postby cj7hawk » Thu Nov 05, 2015 2:08 pm

If you can adjust maximum speed, do that - A drop fro 25kph to 18kph will almost double your range over flat terrain.

Regards
David

Arakasy
Posts: 74
Joined: Tue Jul 15, 2014 8:21 am

Re: Lipo battery loosing charge range

Postby Arakasy » Thu Nov 05, 2015 2:29 pm

Thanks David! Yeah we do this a lot... However it's not the distance we can travel that worries me...it's the fact that his battery is dropping the amount of power he has available... It first dropped at 18,15.8,13.2,12.9...now it's getting to be a joke and running out at 8.9

We used to be able to travel at least 30 km at 40 kph...

Now he can't do 20 km at 25kph... Something is wrong with it
Don't Panic
And I don't know
Ride casual... Not to casual
They might snap out it's comfortable !!

eldavo
Posts: 1587
Joined: Tue Sep 01, 2009 12:21 am
Location: Perth, Western Australia
Contact:

Re: Lipo battery loosing charge range

Postby eldavo » Thu Nov 05, 2015 4:26 pm

How old is the battery and is there any warranty for manufacturer fault?
e.g. if it was happening with your EM3EV battery, you would contact them and ask for troubleshooting.

I hope you didn't buy from edealsbargains:
viewtopic.php?f=51&t=46693

Arakasy
Posts: 74
Joined: Tue Jul 15, 2014 8:21 am

Re: Lipo battery loosing charge range

Postby Arakasy » Thu Nov 05, 2015 6:37 pm

No I purchased this battery from a business in or near Brisbane that sells trikes... I vowed never to return due to extremely poor service... Which is why I went to Paul the boss man at em3ev for my bafang and battery. I also promptly forgot the damn name of the joint I purchased dads from.... Just go to em3ev.com for good stuff is my new anthem

I'm in the process of putting funds together to get him a good one from Paul, but it's going to take a bit, funds don't come easy :(

The only support I got from the Brisbane guy was to send the original battery back as it was doa...that took 2 months of hassles and phone calls. And I received this pos battery in return... At least it turned the bafang on.
Don't Panic
And I don't know
Ride casual... Not to casual
They might snap out it's comfortable !!

geebee
Posts: 186
Joined: Sun Oct 12, 2008 4:55 pm

Re: Lipo battery loosing charge range

Postby geebee » Thu Nov 05, 2015 6:49 pm

The most likely answer is that the batteries are not rated to handle the discharge rate being used, it will cause rapid deterioration of the battery and will be irreversible.
Now if you are lucky it may just be a bad cell in the pack, open up the pack and measure the cells to find the weak link, if you find it just replace it. It may get a bit more complicated dependent upon the series/parallel layout but if you get that far just let us know and I should be able to talk you through it, hope you have a multi meter :)

Arakasy
Posts: 74
Joined: Tue Jul 15, 2014 8:21 am

Re: Lipo battery loosing charge range

Postby Arakasy » Fri Nov 06, 2015 1:33 am

Image

That's the babies..: the yellow one is dads
Don't Panic
And I don't know
Ride casual... Not to casual
They might snap out it's comfortable !!

jdh500
Posts: 54
Joined: Thu Mar 19, 2015 9:19 pm

Re: Lipo battery loosing charge range

Postby jdh500 » Sat Nov 07, 2015 10:07 am

Do you know what the setting is for maximum current draw from the bafang controller? The default would be 25a amps, if you have access to a firmware control cable you can program this to a lower setting such as 20 amps. If your battery is unable to supply the needed current then either replace the battery with one that can or limit the maximum current to what it can deliver.

If your trying to maximise the life of the battery you only let it discharge to 20% of capacity and charge it to a maximum capacity of 80%. This however won't help your situation if the battery is already damaged. I'm using a 10.5ah rocket battery pack on my 750 w bbs02 with current limited to 20 amps and charge to 80%, I only have a short commute and use about 4ah per day.

JDH

softy
Posts: 1663
Joined: Sat Jan 25, 2014 3:44 pm

Re: Lipo battery loosing charge range

Postby softy » Sat Nov 07, 2015 11:16 am

To me it sounds stuffed!

Sorry for the bad news, yes you can identify the cell that is dropping faster than the others (by voltage monitoring across each cell) on a capacity test, but after replacement, probably the next weakest will rear it's ugly head and so on. Batteries are like chains, only as good as the weakest link (or cell).

geebee
Posts: 186
Joined: Sun Oct 12, 2008 4:55 pm

Re: Lipo battery loosing charge range

Postby geebee » Sat Nov 07, 2015 11:24 am

I know all the theory on LiPo but my experience is just charge to full and use whatever is needed, I generally would not go below 50% just because thats how far I ride.
My hobby lipo's are over 4 years old and my Tornaro/Aseako battery is from 2011, neither showing signs of age.

geebee
Posts: 186
Joined: Sun Oct 12, 2008 4:55 pm

Re: Lipo battery loosing charge range

Postby geebee » Sat Nov 07, 2015 11:28 am

softy wrote:To me it sounds stuffed!

Sorry for the bad news, yes you can identify the cell that is dropping faster than the others (by voltage monitoring across each cell) on a capacity test, but after replacement, probably the next weakest will rear it's ugly head and so on. Batteries are like chains, only as good as the weakest link (or cell).


On another ebike forum I frequent there have been many successful Ebike battery repairs by cell replacement, I also have been given LiPo power tool batteries that were dead due to a faulty cell, all of the recovered cells are still in use 3 years on with zero failures.

softy
Posts: 1663
Joined: Sat Jan 25, 2014 3:44 pm

Re: Lipo battery loosing charge range

Postby softy » Sat Nov 07, 2015 11:33 am

geebee wrote:
softy wrote:To me it sounds stuffed!

Sorry for the bad news, yes you can identify the cell that is dropping faster than the others (by voltage monitoring across each cell) on a capacity test, but after replacement, probably the next weakest will rear it's ugly head and so on. Batteries are like chains, only as good as the weakest link (or cell).


On another ebike forum I frequent there have been many successful Ebike battery repairs by cell replacement, I also have been given LiPo power tool batteries that were dead due to a faulty cell, all of the recovered cells are still in use 3 years on with zero failures.


Good news to hear,

What this does mean is the quality control is inconsistent. If one cell has died, and the others have considerable life left it must of been a bad or weak cell from new.

worth a try then for the OP.

Arakasy
Posts: 74
Joined: Tue Jul 15, 2014 8:21 am

Re: Lipo battery loosing charge range

Postby Arakasy » Sun Nov 08, 2015 9:34 am

Hi guys, wonderfully to see a good discussion goin on :)
Ok so it looks like it's 2 weeks till I can get his new battery order placed... I think dads pos will last with the way we have been riding (slow enough for the dog to run beside...) and only for a few hours.

I thank you all for awesome advice... Fact is I'm a scared shitless of pulling these things apart..so we will just wait for the new one :mrgreen: :mrgreen:
Don't Panic
And I don't know
Ride casual... Not to casual
They might snap out it's comfortable !!

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