New Moscow plus 48v, 16a battery only showing 53.4v.

[Tony54]

Hi all,
This is my second ncm new bike. I did my Venice after two years of good use. But I noticed that it only charges to 53.4 volts when the charger cuts off. I tried another 2 amp charger and the same result. I rang the ncm rep and he said it is normally this low, but on my past Venice and my other bafang bike I get 54.4 or there abouts. I also find the battery is temperamental when trying to switch it on, it can take several minutes before it decides to turn on. The ncm rep whilst on the phone and tried other new batteries and said they were all 53v and tried to say that some batteries were 51 to 53 volts new, which I found hard to believe.
Should I demand a new battery, and would it help if I emailed ncm direct.
Thanks for reading.
Tony

 

[Tony54]

How are you measuring the voltage? From your display?

Hi Timpo,
Yes, I'm trusting the display read out. Is their a recommended point to test the voltage? I suppose I could voltmeter across the battery terminals with the battery disconnected but this would be an unloaded voltage is apposed to when the display is turned on, but don't suppose there would be much difference in the reading .
I don't know why, but I assumed the display would be accurate, I will check the battery isolated tomor and let you know.
Thanks for the nudge.
Tony.

 

[harryS]

Displays are not accurate. Neither are most inexpensive voltmeters. If you can reach the pins w/o short circuiting them, check the charger to see what your meter says.

There's hardly any load when the motor is idle, so open circuit battery is close to idle motor condition.

Depending on your battery's health and quality, you'll probably see a .50 to 1.0V drop when the bike is running lightly at 2-3 amps.

 

[RGOLD]

My meter show 0.7v lower then the actual read from on the DVM connected directly to the battery.

 

[Tony54]

I am trying to understand the situation here.

1) You had NCM Venice, do you still have it?
2) You have two ebikes.
3) Can you switch the battery around? So that you can see if the battery has a problem?

 

[Tony54]

Hi Timpo,
I have sold the Venice, I enjoyed using it but it was slightly too big a frame.
I then put a bafang BBS mid drive motor into my decathlon triban hybrid bike which is great on roads and smoother canal paths but not for rougher tracks.
So bought the ncm for the rougher tracks.
I've put the Moscow battery on charge and will voltmeter it when charged and see if its above 53.4 volts.
One would expect a figure of above 54 volts. These batteries are quite precise in their voltages and wouldn't expect more than 0.25 of a volt difference from 54.4 or there abouts.

 

[jkvt]

I think the NCM displays don't read accurate. I had two and both would typically read around 53.6 after a charge. I converted to a KT controller/display and it reads above 54 now when fully charged. I have another bike that I can interchange batteries with and it reads above 54 too. I always had a hunch the NCM displays ready too low, and was frustrated because I assume the low voltage cutoff of the bike is based on that reading (not the battery's low voltage cutoff, that's lower). This would mean the bike would cut out nearly a volt higher than it probably should.

 

[selvakk]

Can confirm, I upgraded from the C7 ncm display and controller to the grin baserunner and cycle analyst. I have been getting 54.1 V consistently at full charge. This is on a battery that has been used for 6000-6500kms over almost 2 years. On the stock display and controller it was reading 53.6 V only.

 

[Tony54]

Hi all responders,
Thanks for all your inputs, I put the battery on charge again and the charger shut off at 53.9 no load measured with a voltmeter. I'm going to accept the battery because I know the battery is giving a good distance without problems.
Incidentally, I was going to buy a 3000 to 4000 ebike for medium off roading but thought I would get the Moscow and use it until the motor packs in or I get bored and then update it with a bafang middrive motor.
Tony