Very short range from battery, trying to diagnose

P

Platypus

100 mW
Joined
Jul 13, 2019
Messages
41
My battery seems to have a very short range.

My setup
- The battery is 520Wh, 52v, 10Ah. It's a shark form factor.
- It is paired to my Tongsheng TSDZ2 mid drive engine, factory firmware, on my recumbent bike - I always ride it with max assistance.

Symptoms
- I did a test ride of 15 miles. The engine cut out at 4 miles, and again at about 12 miles. I would expect a range of 20-30 miles before cutting out. I think it is cutting out automatically to stop it draining too low.
- When fully charged, the display always indicates only 1 bar of charge.
- At the same time, the battery itself shows a good charge: 1 red and 3 green LEDs.
- Performance is good. I can go up 20% slopes. The Rohloff Speedhub is amazing.

I want to know if the battery is faulty, & if so what I can do about it. I have a decent range of tools and a heap of time. Hopefully this post is as concise and easy to read as I can make it.
 
I would open up the battery and look to see what brand and model of 18650 cells they are and let us know but if it cut out at 4 miles then kept working and cut out again at 12 miles were you going up a steep hill or were you just riding easy.

was the battery cold?

almost sounds like a controller issue if your battery gauge on the bike isn't showing a full battery

are you able to adjust the LVC of your controller?

so the shark battery slides off the bike and there are 4 blades on the mount for pos and neg and on the battery underside you have the other set of contacts that the blades go into, sometimes those get loose and need to be pinched back together so theres good contact, that's the first thing id check and is most likely the problem or you didn't have the battery locked to the slider. try the simple things first before opening up the battery
 
Sorry for the delayed reply.
goatman said:
I would open up the battery and look to see what brand and model of 18650 cells they are and let us know but if it cut out at 4 miles then kept working and cut out again at 12 miles were you going up a steep hill or were you just riding easy.

was the battery cold?
Click to expand...
No, mild environment, gentle hills. Not strenuous at all.

I've opened up the battery. All the connections look secure. The cells are a baby pink, cylinder shape, and about 8 cm long. I'm pretty sure it's a red herring, and is a controller issue.
goatman said:
are you able to adjust the LVC of your controller?
Click to expand...
How do I change the Low Voltage Cutoff? I have looked on Google, but can't find any instructions.

Is it possible to do a factory reset on the controller?
 
bms is 30 amp, battery is 14s4p? 10ah, if its 4p then its a light pink 18650 2500mah cell but cant see what it is all I can see is: sinc 18a18650 26a1951353. ill try googling it but

its the random cutting off that is weird like a bad connection or something. I see a bunch of little wires does the battery have an on/off switch with light gauge wiring. if it does id turn on the battery and wiggle test the wires to see if theres a bad/loose connection, using a dmm see if the battery cuts in and out
 
First thing I would do is let the battery sit on the charger for a good long time to make sure that it is not out of balance. One low cell could cause a cell group to go low enough for LVC. Leave it on the charger for a full 12 hours and see if that makes a difference.

While that is happening, carefully check all your connections on the bike to make sure they are well connected. If you are using e-brakes that cut power when pulled, check to see all your brakes are adjusted to make sure that is not the problem.

Once you battery has been on the charger for 12 hours or longer, connect it to your bike and make sure your battery connections are good.

Go for a ride and see what happens.

Also, post pictures of the bars of charge and light so we can see what you see. Make sure they are in good focus.

:D :bolt:
 
I couldn't find anything on that cell but what I noticed while searching is if you see Chinese no name cells they have a + and -(positive/negative) on the wrapper of the cell and I can see a + on your cell wrapper. it would be nice to know the amp rating of the battery
 
Platypus said:
- When fully charged, the display always indicates only 1 bar of charge.
Click to expand...
usually this means the battery's voltage is too low for the system's designed voltage range. that means the system may have an lvc that is setup for a higher voltage battery than yours, and so when your battery drops below that point, the system stops providing assist.


if the entire system including display/etc shuts off when the problem happens, it's the battery's bms shutting off due to a problem in the battery.

but in your case it sounds like that's not happening, and it's just the system staying on but no longer assisting. if that's true, then the battery itself is unlikely to have anything wrong, and it's just a setting (or a hardware limitation) of the controller system.

if you use the opensource firmware (casainho / etc) then afaik it has settings for those things.

but when using the original factory firmware, you'd have to check your manual for those settings, or the main tsdz2 thread (not the opensource thread), if it has any settings (some of these things may be locked by the manufacturer and can't be changed by the user--you have to buy the version you want, and if you want something different you have to buy a new one with those settings or hardware).
 
amberwolf said:
usually this means the battery's voltage is too low for the system's designed voltage range. that means the system may have an lvc that is setup for a higher voltage battery than yours, and so when your battery drops below that point, the system stops providing assist.
Click to expand...
@amberwolf thank you for contributing. I run the factory firmware. I agree that the battery is fine.

I'll be honest. I feel that in this thread, we have been chasing the battery as a scapegoat, when the problem more likely the controller.

Look at the evidence again. I left the battery charging for 24 hrs. It must be fully balanced. The indicator on the side says it is well charged. My multimeter says it is 55v. That is exactly what I would expect from a fuctioning battery.

However, the display says the battery is nearly flat. It cuts out every few miles, probably in an attempt to protect the battery draining far too flat. It is as the battery is 52v, but the motor is 60v; therefore the motor is always expecting a higher voltage. (When new, it worked fine.)

Would people concur problem is more likely to lie with the motor, than the battery? If so, I might have rights I can exercise under warranty.
 
One can say that the battery is fine, but unless a proper testing methodology is used to determine proof positive that it is fine, there is no way to tell for sure. The only way to track down the problem is to do a proper process of elimination. The battery might take a full charge but still not be able to take a full load. Did you charge it for 24 hours, meter the voltage then let the battery sit overnight to see if it drops in voltage substantially?

And, why does your display indicate a low charge. That also brings up the question about the settings on your display.

Is your display a Cycle Analyst?

As for the motor, controller and battery, please post the best spec sheets you can. It will help us help you.

:D :bolt:
 
Platypus said:
amberwolf said:
usually this means the battery's voltage is too low for the system's designed voltage range. that means the system may have an lvc that is setup for a higher voltage battery than yours, and so when your battery drops below that point, the system stops providing assist.
Click to expand...
@amberwolf thank you for contributing. I run the factory firmware. I agree that the battery is fine.

I'll be honest. I feel that in this thread, we have been chasing the battery as a scapegoat, when the problem more likely the controller.

Look at the evidence again. I left the battery charging for 24 hrs. It must be fully balanced. The indicator on the side says it is well charged. My multimeter says it is 55v. That is exactly what I would expect from a fuctioning battery.

However, the display says the battery is nearly flat. It cuts out every few miles, probably in an attempt to protect the battery draining far too flat. It is as the battery is 52v, but the motor is 60v; therefore the motor is always expecting a higher voltage. (When new, it worked fine.)

Would people concur problem is more likely to lie with the motor, than the battery? If so, I might have rights I can exercise under warranty.
Click to expand...
you said its although the motor is 60v and the battery is 52v. I had a problem like that. I used a 60v 33amp controller from a scooter with sla batteries. the lvc of the controller was 52v or 50v so when I hooked up my 13s pack to it, 54.6v, it would run but cut out right away under throttle/load while riding. youre starting at 58.8v so you would get some range if not pulling too many amps before it started cutting out.
 
It is relatively trivial to prove the battery capacity, also watch the voltage sag under different C-rates.

Thus maybe eliminating that as the cause.

Testing the rest will take either a known good battery, or a powerful PSU with adjustable V&A output, plus test instruments of course.

The rest is speculation.
 
Platypus said:
Look at the evidence again. I left the battery charging for 24 hrs. It must be fully balanced. The indicator on the side says it is well charged. My multimeter says it is 55v. That is exactly what I would expect from a fuctioning battery.

However, the display says the battery is nearly flat. It cuts out every few miles, probably in an attempt to protect the battery draining far too flat. It is as the battery is 52v, but the motor is 60v; therefore the motor is always expecting a higher voltage. (When new, it worked fine.)
Click to expand...

You need more data to get a good diagnosis.

I'm glad to see that you have a multimeter. Do you also have a power meter in series with the battery, something like this? Just for troubleshooting, wiring up a long battery cable that lets you mount the power meter on your handlebars would be super helpful.
https://www.amazon.com/HTRC-Precision-Analyzer-Battery-Voltage/dp/B06XPVKY13

Very useful questions to know the answer to:
  • What voltage are you charging to?
  • What voltage is the battery cutting out at?
    --This is actually a tricky question. Remember that battery sags under use, so the voltage that you measure after the controller cuts out is different than the battery voltage as the controller cuts out. The measurement that you really want is the battery voltage as the controller cuts out. This is going to be very hard to get without mounting that power meter on your handlebars for troubleshooting. (It's temporary and doesn't have to be pretty. Lamp wire and zip ties...)
  • What's your average power draw or amperage?
  • What's your peak power draw or amperage?
  • Lastly, what's the Low Voltage Cutoff on the controller?

I'd give better than even odds that the "problem" is the battery voltage ducking below the Low Voltage Cutoff set on the controller, and that it's likely correlated to voltage sag from high current draw, higher current than you anticipated in your design.
 
Platypus said:
Look at the evidence again. I left the battery charging for 24 hrs. It must be fully balanced. The indicator on the side says it is well charged. My multimeter says it is 55v. That is exactly what I would expect from a fuctioning battery.

However, the display says the battery is nearly flat. It cuts out every few miles, probably in an attempt to protect the battery draining far too flat. It is as the battery is 52v, but the motor is 60v; therefore the motor is always expecting a higher voltage. (When new, it worked fine.)
Click to expand...

Maybe you're using a 48V pack, thinking it's a 52V pack? A fully charged 48V pack is 54.4V. A fully charged 52V pack is 58.8V. If you charged it enough to balance it, then your DMM should read 58.8V.
 
52v does not exist from Tongsheng. Watch this video:

http://mfqczy4mysscub2s.onion/watch?v=Jwi9nW2TAHg

At the very end of that video, they hold up a statement from Tongsheng saying they do not make a 52v motor. As such, they also say there is no warranty on 52v kits.

Did you buy an aftermarket controller? I've seen 52v kits and was thinking about getting one, but I'm going to nix the idea of importing a 52v tsdz2. I'm thinking I'll only buy a 52v kit domestically, and only if the dealer gives a warranty of their own.
 
xtinctionRebeller said:
52v does not exist from Tongsheng. .....
Did you buy an aftermarket controller? ....
Click to expand...
All controllers for the TSDZ2 are exactly the same (63Vmax). The voltage and power is regulated by the controller software.
When flashing modified or osf firmware it is possible to run the motor with a higher voltage and/or power than Tongsheng has done.

For the short range problem. E-HP could have a point.
Also it could be that some batteries in a row aren't good enough.
A batterypack is as good as the weakest cell, so balancing at 58V isn't possible then.
 
Elinx said:
All controllers for the TSDZ2 are exactly the same (63Vmax). The voltage and power is regulated by the controller software.
When flashing modified or osf firmware it is possible to run the motor with a higher voltage and/or power than Tongsheng has done.
Click to expand...

Thanks, glad to know there's no variation on all the controllers we see in the market. It certainly implies that it's foolish for someone who has a 36v motor to buy a 48v replacement controller, assuming we neglect warranties.

Obviously flashing the controller with open source firmware voids the warranty. So now I'm considering:
  1. buying a motor from a vendor who ships it with open source f/w, 1+ yr warranty included; OR
  2. buying 36v or 48v OEM rig, and only flash it with open source f/w after the warranty period ends (but before the credit card's warranty extension ends)

edit: hold on, now I'm seeing a post from casainho saying there are a 36v motor differs from a 48v motor. If that's true, then the software isn't the end of the story.

And just to be clear, is firmware the only difference between this 48v motor and this 52v motor? So in effect, the extra $50 is to pay auto-ebike.com to flash and config the controller?
 
The BMS in the pic says 14s. 14 cells in series should be 58v-58.8v fully charged.

Check the output of your charger without the batteries hooked up to it. That should give you a good idea what the chargers max voltage is. If its 55v then you aren't charging all the way. If it is 58v then something is wrong with your pack.
 
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