assist cut off ?

[Nealh]

Just because a battery might charge to full , doesn't mean it is healthy. It just means the cells wil accept a full charge.
Under load they may be suffering and voltage can sag terribly , this will lead to poor power delivery.

 

[Alm]

Just because a battery might charge to full , doesn't mean it is healthy. It just means the cells wil accept a full charge.
Under load they may be suffering and voltage can sag terribly , this will lead to poor power delivery.

Hello again, I'm back regarding my Kildemoes egoing citybike 2017 36V. The problem was the assist falls off after approx. 6-8km of fully charged battery. the battery has now been tested and here is the answer to the test. Hello Lars. I have looked through the battery and the cells are ok, and the BMS no damage. So I've now done a stress test, and

Just because a battery might charge to full , doesn't mean it is healthy. It just means the cells wil accept a full charge.
Under load they may be suffering and voltage can sag terribly , this will lead to poor power delivery.

Hello again, I'm back regarding my Kildemoes egoing citybike 2017 36V. The problem was the assist Cut off after approx. 6-8km of fully charged battery. the battery has now been tested and here is the answer to the test.
Hello Lars. I have looked through the battery and the cells are ok, and the BMS no damage. So I've now done a stress test, and the capacity is measured at 12.5 Ah, and it doesn't switch off all the way through...
I don't know if that's enough of an answer for you experts, but that's the answer I got?
So if it's not the battery then there can only be the controller or the motor left. ? can display possibly make a problem like that. ?
Crank sensor has been replaced and all cables and connectors checked and lubricated with contact spray.
I have found that when the problem is there, can I increase the speed myself to approx. 20km/h and get the assistant to engage again? Hope you Can help me.

 

[Alm]

Hi I have try to messure the output from the charger, but could not get any messure I could use, I spole with the guy who has tested the batteri and He told me that because it was a 5 pins jack I could not get a prober messurement, but now he has done it and he told me that the charger was ok.

 

[saneagle]

The guy gave you the results of a capacity test, not a stress test. What current did he run it at? What was the maximum sustained current that the battery could give?

 

[joelectric]

Hi I have try to messure the output from the charger, but could not get any messure I could use, I spole with the guy who has tested the batteri and He told me that because it was a 5 pins jack I could not get a prober messurement, but now he has done it and he told me that the charger was ok.

What voltage did the charger read? you need to ask for this information, the guy testing it saying its fine isn't good enough for fault finding.

 

[Alm]

The guy gave you the results of a capacity test, not a stress test. What current did he run it at? What was the maximum sustained current that the battery could give?

Hi Saneagle
This was what the guy told me.
Hello Lars. I have looked through the battery and the cells are ok, and the BMS no damage. So I've now done a stress test, and the capacity is measured at 12.5 Ah, and it doesn't switch off all the way through...

 

[saneagle]

Hi Saneagle
This was what the guy told me.
Hello Lars. I have looked through the battery and the cells are ok, and the BMS no damage. So I've now done a stress test, and the capacity is measured at 12.5 Ah, and it doesn't switch off all the way through...

When cells become old, they lose their ability to provide current. If you draw a high current, the voltage goes right down and it cuts off. If you only draw low current, they stay on and can give good capacity. If somebody gave me a battery for checking, I'd test it at about 10 amps to see how much the voltage drops. A good battery might only drop 1v and a bad one 10v or even more. Your tester must have run his test at some current. Was it 1 amp for 15 hours, 15 amps for one hour or what? You should ask him.

 

[Alm]

When cells become old, they lose their ability to provide current. If you draw a high current, the voltage goes right down and it cuts off. If you only draw low current, they stay on and can give good capacity. If somebody gave me a battery for checking, I'd test it at about 10 amps to see how much the voltage drops. A good battery might only drop 1v and a bad one 10v or even more. Your tester must have run his test at some current. Was it 1 amp for 15 hours, 15 amps for one hour or what? You should ask him.

Thank you for your answer, I have just send the guy who had made the test a mail , so I have to wait for his answer. Thanks

 

[Nealh]

Apart from 12.5ah capacity test as mentioned he hasn't given any testing figures , current loading and duration are needed. If he tested at at a lowly 0.5a - 1a then the battery will not have been stress tested to show up any fault.

 

[Nealh]

Going back to your first post, I had a battery (actually two the same) and I had the same fault as you had. I could ride 64km in PAS 1 but when using PAS 3 , I would only get about 29km and the bike would cut out sometimes due to voltage sag. The batteries were ageing and starting to get tired for bicycle use if used above PAS 1.

 

[Alm]

Hi there
Here are what He just send me. it is stress tested with constant 8A approximately ~300w and it is measured at 12.5 Ah in total. How long did it take? If it sucks say 8A per hour, then it is approximately 1.6 hours
Hope this is little help , I realy appreciate your all your help. thanks.

 

[Alm]

Hi there
Here are what He just send me. it is stress tested with constant 8A approximately ~300w and it is measured at 12.5 Ah in total. How long did it take? If it sucks say 8A per hour, then it is approximately 1.6 hours
Hope this is little help , O

 

[Nealh]

8a one assumes is approx. 50% of you controller rating , it might just be that the cells simply can't handle the extra speed and the current in PAS 3.
One is assuming as you have a 3 PAS display it is speed control , ultimately one expects the battery cells are just unable to cope.