42v charger only 37v output?????

Kristoffer P

Finding my (electric) wheels
Feb 13, 2018
8
2
45
Denmark
Hello from Denmark, what is wrong with my cyclotricity bottle batt kit. Almost new 2 happy months and not sending it back because i need to learn this emagic. Power went down to 37 v over a few days and the 10 cell groups were reading okay. Then replaced bms and that did NOT help my charging problems. Why the h..ll ar my charger only putting out 36.9 volts and not the 42 v it says on back.? Bourght one new charger and messured that to 36.9 v also before changing bms. I kinda feel like i need 42 volts comming in to my battery chargong port. The charger shows charging up to 36.9 v and then stops. What is going on? I really enjoy my ebike but this drives me a little nuts.
 

Woosh

Trade Member
May 19, 2012
20,068
16,744
Southend on Sea
wooshbikes.co.uk
recheck the setting of your Volt meter. If you select AC instead of DC, you'll get a wrong reading.
Check also the output voltage of youur battery against the number of bars on your LCD to confirm the reading on your voltmeter.
 

Kristoffer P

Finding my (electric) wheels
Feb 13, 2018
8
2
45
Denmark
DC is on and output reads 36.9 volts on the discharge connectors underneath the battery. Led also shows nothing at this stage.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,767
8,448
61
West Sx RH
Can you confirm with a new voltage reading the charger output with it plugged in the wall but not to the battery please.
The charger as you say should read 42v when plugged in to the mains if not then the charger might be faulty but first try a new battery in your volt meter.
 

Woosh

Trade Member
May 19, 2012
20,068
16,744
Southend on Sea
wooshbikes.co.uk
DC is on and output reads 36.9 volts on the discharge connectors underneath the battery. Led also shows nothing at this stage.
check the voltage display on your LCD.
37V should show as 3 bars on a 5 bar display.
if the voltage on your LCD shows full (5 out of 5) then you need to replace the battery in your voltmeter.
 

Kristoffer P

Finding my (electric) wheels
Feb 13, 2018
8
2
45
Denmark
Can you confirm with a new voltage reading the charger output with it plugged in the wall but not to the battery please.
The charger as you say should read 42v when plugged in to the mains if not then the charger might be faulty but first try a new battery in your volt meter.
I will try with a fluke voltmeter at work tomorrow.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,767
8,448
61
West Sx RH

Kristoffer P

Finding my (electric) wheels
Feb 13, 2018
8
2
45
Denmark
check the voltage display on your LCD.
37V should show as 3 bars on a 5 bar display.
if the voltage on your LCD shows full (5 out of 5) then you need to replace the battery in your voltmeter.
I only have led indicators, 4 pcs, no lcd display. And 37 volts is below 1 pcs.
 

Kristoffer P

Finding my (electric) wheels
Feb 13, 2018
8
2
45
Denmark
OMG my voltmeter was faulty by almost 5 volts!! Charger output 41.7 messured at work and i belive my battery must be the same when i arrive home to controll it.
What a nice way to learn about ebikes:confused:
Now if i only had a spare controller. ....
 
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Nealh

Esteemed Pedelecer
Aug 7, 2014
20,767
8,448
61
West Sx RH
Your meter may be out because it needs a new battery if that is not the answer get a ne meter, make sure it is one with continuity buzzer for wire/ circuit fault finding.

It did appear a strange scenario that 2 new chargers were thought faulty.
When you get strange results/readings it's always worth checking with a different meter so always handy to have two different models/brands as they are cheap to buy.
 

Nealh

Esteemed Pedelecer
Aug 7, 2014
20,767
8,448
61
West Sx RH
Now if i only had a spare controller. ....
If it's KT then they are easy to get hold of from China, via PSWPower/Elifebike , BMSBattery or Aliexpress.
 

Kristoffer P

Finding my (electric) wheels
Feb 13, 2018
8
2
45
Denmark
Well it was the cable from controller to display that was broken inside, 3 months old and no signs of wear at all. It really was not easy to find that fault at all.
Cyclotricity replased it and i must say that they respondet quickly to my emails and they did what any consumer would like a shop to do when a product fails. Thanks cyclotricity. Bike running strong again.
 
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