Help! Samebike 20LVXD30 48v Charging Problem

[Nealh]

Check the 13a plug fuse and possibly the charger may hav an internal one.
Check your meters battery is ok and working correctly by testing another source, a kettle plug for example or simpll any battery source.

 

[squirrel22]

Thanks. I've just checked the charger with two meters and both read 54.7v
I'm not sure what happened yesterday when I couldn't see a voltage on the meter. I'd assumed the charger had shut off.
Unless anyone can think of a charger issue that could still affect this, I think it narrows down the problem to the battery or the BMS?

 

[Nealh]

Charger is fine then.
As the bike is new then it is under warranty, one needs to contact the vendor first before attempting any battery experiments to get it working.
Sounds like the battery may be in a sleep mode, try pressing the battery switch for 10 - 30 seconds then try a charge. Other wise first contact the vendor.

 

[squirrel22]

Thanks Nealh.

I'm really struggling to get any joy from the vendor, Rymic. They don't seem to understand English well or what they are selling and are not very responsive either. I thought I was getting an "upgraded Rymic bike" and a Samebike 20LVXD30 turned up. Its the same spec and I love the Samebike other than the battery issue. The user manual could say a lot more than it does! I tried contacting Samebike and they said (understandably) try the vendor first before reverting to them. I've just tried taking a video and sending it to Rymic so I'll see if they understand what I've sent them.

I wasn't certain what you meant by the "battery switch". Did you mean to turn the ignition key to on for 10-30 secs? I thought it was just a locking key but I've tried doing that and nothing changed.

 

[Nealh]

Battery should have it's own on/off button aka switch.

Sadly that's the joy of some China vendors, one get very poor CS when a problem occurs.
Any waarranty may be zilch if one tries to affect a repair by opening anything.

 

[squirrel22]

Thanks. Hmm, I can't spot an obvious on/off button.

Rymic (the seller) seem to think that a full charge of 48.6v is fine for a 48v battery! I explained that 48v is the mid point between fully charged at 54v and empty at 41v but they don't understand this and/or English so CS is near zero. I'm trying samebike.store to see if they will "adopt" my bike. It doesn't help that Rymic changed their website completely since I bought on 9th Aug and no longer show this bike or allow you to view your account/invoice. ... caveat emptor I guess!

 

[Nealh]

Sounds like a company who don't know much about the tech specs of the bike they are selling.

 

[squirrel22]

I thought I should post an update as my saga has turned out well.

I bought a "Rymic Upgraded bike" which turned out to be a Samebike E-One 20LVXD30. Very happy with the bike of course other than the battery which wouldn't charge beyond 48.6v. Rymic (Topo Ltd) sent me a replacement DCH-006 battery which charged up to 54.3v on first charge which I've accepted as okay.

There have been communication problems with Rymic which dragged on a couple of weeks. These were both language difficulties and their customer service people not understanding that a 48v battery should charge to 54.6v. Once they referred it to their engineer it was resolved quickly.

Along my travels of understanding whether the problem was the battery, battery management system or the charger I bought a variable charger from DigiKey which only took 2 days to delivery. I'm really impressed with it. Voltage can be set between 42-60v at 2 Amps (mine seems to be variable between 37.3-62.3v which would cater for people with 36v, 48v or 52v bike batteries). https://www.digikey.co.uk/en/products/detail/mean-well-usa-inc/NPB-120-48TB/14682595

 

[Nealh]

Pleased thye sorted out the issue and got yhere in the end.
Did the duff battery havr to go back or did you get to keep it ?

 

[squirrel22]

Pleased thye sorted out the issue and got yhere in the end.
Did the duff battery havr to go back or did you get to keep it ?

They haven't asked (as yet) and I haven't suggested it
My thoughts are to leave it a month and if I hear nothing I'll strip the battery pack down and track down the offending cell(s) to replace. The Youtube video of dissecting the DCH-006 battery is a good one

- it looks a convoluted way of squeezing all the cells in but doable.

 

[Nealh]

I would first check all cell groups to see what the 13 seperate voltages read and then go from there, if all the same I would likely think the BMS is at fault.

 

[squirrel22]

I would first check all cell groups to see what the 13 seperate voltages read and then go from there, if all the same I would likely think the BMS is at fault.

I'd rather it was the BMS to be frank as that would be much easier to fix

 

[Andy-Mat]

They haven't asked (as yet) and I haven't suggested it
My thoughts are to leave it a month and if I hear nothing I'll strip the battery pack down and track down the offending cell(s) to replace. The Youtube video of dissecting the DCH-006 battery is a good one

- it looks a convoluted way of squeezing all the cells in but doable.

When a quality battery is manufactured, all the cells must be of the exact same type, and from the same manufacturer.
No mixing with cells from different sources...or different versions!
Some people (not me!) who build their own batteries, even insist that the cells are all made on the same day, and from the same batch.......And all the cells need to be extensively tested, to make sure that they have the same characteristics, which means that some cells may simply not be "good enough".......even though brand new.....though good manufacturers also grade their own cells to match up into sets for selling.
These are some of the reasons why I have never attempted to build a battery myself.....
Best wishes
Andy

 

[squirrel22]

When a quality battery is manufactured, all the cells must be of the exact same type, and from the same manufacturer.
No mixing with cells from different sources...or different versions!
Some people (not me!) who build their own batteries, even insist that the cells are all made on the same day, and from the same batch.......And all the cells need to be extensively tested, to make sure that they have the same characteristics, which means that some cells may simply not be "good enough".......even though brand new.....though good manufacturers also grade their own cells to match up into sets for selling.
These are some of the reasons why I have never attempted to build a battery myself.....
Best wishes
Andy

Thanks Andy thats a good point. I'll keep fingers crossed its the BMS and not cells that's the problem.
If it is a cell(s) I'll still want to make it a useable battery. I imagine its the 13 cells in series that will be the difficulty as its not viable to de-weld all the cells so checks would have to be done with the cells in situ. Individual cell voltages can be measured but is it their internal resistance which is the issue? I guess I could rig up some form of load (bulb) to apply to individual cells and measure current with the load? Any thoughts on this?

 

[StuartsProjects]

These are some of the reasons why I have never attempted to build a battery myself.....

Me neither.

I would also not even think about trying to match replacement cells to a high enough level that would make a re-built battery 'safe'.

Its also possibly a subject that if you need to ask questions about it, maybe consider not doing it.

I am an Electronics Design Engineer by training and have a fair amount of experience using Lithium batteries in RC models, but my views on Lithium batteries in general are somewhat jaundiced by an incident when an exploding Lithium polymer battery on charge almost killed me.

 

[Andy-Mat]

Thanks Andy thats a good point. I'll keep fingers crossed its the BMS and not cells that's the problem.
If it is a cell(s) I'll still want to make it a useable battery. I imagine its the 13 cells in series that will be the difficulty as its not viable to de-weld all the cells so checks would have to be done with the cells in situ. Individual cell voltages can be measured but is it their internal resistance which is the issue? I guess I could rig up some form of load (bulb) to apply to individual cells and measure current with the load? Any thoughts on this?

I hope for your sake that its just (!!) a BMS problem......
To "build" (or take apart!) a battery, a battery welder is a handy tool to have, I am told, and some simple designs can be home made, using parts taken from an old Microwave! See the web for details.
Testing each cell, if needed, will be a bummer, but I am sure some here can help you further, but that really is "load testing" each cell (UGH!), and if you are lucky, it will only be a couple, and you can reduce the number of cells in each block, giving reduced power range, but still useable..... Just a thought......
Best wishes and let us all know how it works out for you.
Regards
Andy

 

[squirrel22]

I hope for your sake that its just (!!) a BMS problem......
To "build" (or take apart!) a battery, a battery welder is a handy tool to have, I am told, and some simple designs can be home made, using parts taken from an old Microwave! See the web for details.
Testing each cell, if needed, will be a bummer, but I am sure some here can help you further, but that really is "load testing" each cell (UGH!), and if you are lucky, it will only be a couple, and you can reduce the number of cells in each block, giving reduced power range, but still useable..... Just a thought......
Best wishes and let us all know how it works out for you.
Regards
Andy

 

[Andy-Mat]

Me neither.

I would also not even think about trying to match replacement cells to a high enough level that would make a re-built battery 'safe'.

Its also possibly a subject that if you need to ask questions about it, maybe consider not doing it.

I am an Electronics Design Engineer by training and have a fair amount of experience using Lithium batteries in RC models, but my views on Lithium batteries in general are somewhat jaundiced by an incident when an exploding Lithium polymer battery on charge almost killed me.

Good and sensible advice, experience is a hard school.
I think that the more one knows about Li-ion battery building/repair, the less inclined one is to actually do it!!
regards
Andy

 

[squirrel22]

Good points Andy. If it was just one dodgy cell then reducing each series to 12 cells would still be positive for me as it could bring the potential max voltage of the original battery up to 50.4v from its current 48.6v so still a success.
I think I'll look out for a big enough metal box that would take the charger and battery for charging in case of run away problems.

 

[StuartsProjects]

I think that the more one knows about Li-ion battery building/repair, the less inclined one is to actually do it!!

Yep.