Hailong 48v 17.5ah constantly reading 100%

ceptic

100 µW
Joined
Feb 21, 2021
Messages
7
Hi All,

I've searched but can't find any posts detailing the issues I am having with a Hailong 48v 17.5ah battery powering a TSDZ2 motor. I have just noticed on the last 3 rides that the TSDZ2 display and the battery display shows 100% charge irrespective of the distance ridden ie the battery voltage isn't apparently dropping. On my last ride we covered 45km and 23km was in turbo mode with no change. I know I should have checked the battery voltage at the discharge ports but I had misplace my multimeter. I can take a 42km ride tomorrow and use the MM to test the starting voltage and the end voltage. While I am waiting for that is this a BMS issue and is there anything I can do to investigate this further?

Thanks in advance
 
I find that the pictogram battery indicators are not all the same, but they're all so unreliable or inaccurate as to be useless. If you need to know what your state of charge is, have a voltmeter and know what the numbers mean.
 
Thanks and the battery LED display constantly reads full even at the end of a long ride. I am just worried that the battery is telling the display that the voltage is 52-54v when it isn't. My thoughts are that if this is the case the BMS won't be working correctly and I may be over discharging the battery (ie BMS based cutoff won't trigger).
 
ceptic said:
I've searched but can't find any posts detailing the issues I am having with a Hailong 48v 17.5ah battery powering a TSDZ2 motor. I have just noticed on the last 3 rides that the TSDZ2 display and the battery display shows 100% charge irrespective of the distance ridden ie the battery voltage isn't apparently dropping. On my last ride we covered 45km and 23km was in turbo mode with no change. I know I should have checked the battery voltage at the discharge ports but I had misplace my multimeter. I can take a 42km ride tomorrow and use the MM to test the starting voltage and the end voltage. While I am waiting for that is this a BMS issue and is there anything I can do to investigate this further?
The bms doesn't talk to the display on iether the bike or the battery case, so unless the battery either isn't working or never shuts off, the bms is likely ok (but isn't relevant to the display issue either way). The battery doesn't tell the display anything. The display is basically just a voltmeter that reads in levels rather than digits, for both the one on the battery case and the one on the bike itself. It's all pretty "dumb" technology.


Without a voltmeter there's not a lot you can check; riding till shutoff of the battery would tell you if the bms is working and shutting off, but it won't do anything to fix the display afaik.

If both displays stay at max all the time, but never did this before, then you should try to think of every little thing that has happened to the bike between the time it didn't do this and the time it did. One or more of those things is probably the issue.

It is strange for them both to suddenly malfunction the same way, so the cause is probably a common event.



Unlikely since overcharge would have been used up quickly, but: Do you have any batteries that are 52v 14s, vs this 48v presumably 13s battery, that could have had their chargers plugged into it by accident? if the bms didn't work to shut off charging it could have overcharged the pack beyond what hte meters can read, but that extra charge should have been used up pretty quick and then the meters would read correctly again.
 
Fantastic information regarding the BMS and while I do have a 52v battery the charge ports are different so no chance of connecting the wrong charger. I was thinking of riding until shutdown and taking multimeter readings along the way to check if the BMS is protecting from excessive discharge. The only thing that has happened with this bike is that it had a very long period of sitting with full(ish) battery. The battery is currently 'fully charged' so I will get the multimeter onto it to see if it has been overcharged.

Thanks to everyone for your advice so far
 
Used to be the 36V TSDZ2 would not run on 48V, but that's because there was a register in the TSDZ2 programming that would inhibit running at higher voltage. Maybe they updated the firmware to allow the motor tor run, but they didn't tell the voltage-to-bar algorithm.
 
Use a throttle with a voltage readout
https://www.amazon.com/Voltage-Display-Throttle-Digital-Battery/dp/B0811H7NP4
 
docw009 said:
Used to be the 36V TSDZ2 would not run on 48V, but that's because there was a register in the TSDZ2 programming that would inhibit running at higher voltage. Maybe they updated the firmware to allow the motor tor run, but they didn't tell the voltage-to-bar algorithm.

Thanks and this could possibly be the issue... I will continue to scour the forums!!

calab said:
Use a throttle with a voltage readout
https://www.amazon.com/Voltage-Display-Throttle-Digital-Battery/dp/B0811H7NP4

An interesting suggestion...
 
The Battery tested at 53.2v this morning before we set out for a 44km ride where my wife had it set on 2,3 or 4 /4 for the majority of the ride. There was 470m of elevation gain in the ride and we averaged 16km/h. The last 10km saw my wife using the throttle frequently. The battery currently reads 50.4v so that explains it reading full on the display and the inbuilt monitor. Now to figure out why it only used up 3 volts (wife did comment that she felt there was less assist at the end than there was at the beginning). I guess we will keep using it until the voltage drops further while monitoring perceived assistance?
 
ceptic said:
The Battery tested at 53.2v this morning before we set out for a 44km ride where my wife had it set on 2,3 or 4 /4 for the majority of the ride. There was 470m of elevation gain in the ride and we averaged 16km/h. The last 10km saw my wife using the throttle frequently. The battery currently reads 50.4v so that explains it reading full on the display and the inbuilt monitor.
If it helps:
53.2v / 13s = 4.09v/cell (4.2v/cell is full)
50.4v / 13s = 3.88v/cell (3.7v/cell is about half full)
Around 42v is usually "empty". (around 3.3v/cell) (controller LVC for "48v" packs)
BMS shutoff is "emergency" level, at dead empty, usually at or above 2.8v/cell, or 36-37v. Don't usually want to do that much; hard on the cells.
 
Thanks so I wonder why both the display and inbuilt battery monitor are reading full? I know they are not acurate and just ballpark figures BUT there is a big difference between 100% and 50% ie 75% level should come in there somewhere. I will keep using it without charging, monitor the voltage with my multimeter and see if the levels change shortly.

Thanks for all of your suggestions and advice.
 
Update: Did another 40km of trail riding again today with 400+m of elevation gain. Didn't charge the battery and increased the controller amps to 18A-max (from factory 16A-max). Wife reported PAS was more responsive and multimeter voltage now reads 46.8V post-ride. Both display and battery both identify a reduction in battery capacity. Obviously I was not giving the battery the respect it deserved by assuming it should be depleting quicker than it did.

Thanks to everyone for their input on this matter.
 
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