Battery doesn’t charge beyond 84%

dodjaki

New Member
Hi,
I bought a Eunorau bike and when I charge it completely it reaches only 84%
During charging, red light is on.
end of charging: green light come on.
even after I leave it an extra hour on green light , it never charges beyond 84%
maybe the 84% reading is wrong.
has anyone the same experience ?
Is something wrong with the battery or the charger ?
Does any one have a solution for bringing the reading to 100%
thanks for your help.
 

rich c

Well-Known Member
Did you measure voltage with a multimeter? Knowing the exact voltage is necessary vs a percentage reading. Maybe they sent you the wrong battery pack. Like a 36v instead of a 48v.
 

Thomas Jaszewski

Well-Known Member
Did you measure voltage with a multimeter? Knowing the exact voltage is necessary vs a percentage reading. Maybe they sent you the wrong battery pack. Like a 36v instead of a 48v.
YES! How are you reading 84%? I never trust "indicators" best to actually MEASURE voltage! What is the rating on the charger?
 

Browneye

Active Member
Check for a display setting for voltage - maybe it's set for 52v.
Or perhaps you got a 52v battery.

And yes, put a volt meter on the battery lead after a full charge - it should be close to the 54v full charge value. If so it would indicate an errant value on your display.

A 48v charger won't peak a 52v battery to its near 60v capacity.
 

harryS

Well-Known Member
You're not going to know until you get a voltmeter on the battery terminals. A 48V battery is 54.6 volts at maximum charge, and can be run down to around 40-42 volts at which point the bike controller will shut down.

The capacity is not linear. 85% means it's seeing 52.3 volts. 50% is around 47 volts. It's kind of silly, in my opinion, to assign a percentage to the battery capacity on a display. Better to to just show levels.

As for the charger, you can measure its no load voltage, which should be 54.6V. The way most chargers work, they sense when the battery is not drawing any further charge current and the LED flips to green. The final voltage does not have to be 54.6 when this happens. If it did shut off too low, leaving the charger connected will sometimes allow the battery to balance internally and increase the final voltage.

A brand new battery might be a little low, no more than 1 volt. Run it down, recharge it, and it should hit its max after 2 or 3 cycles. That's why you want to put a voltmeter on it and see if it really is 2 volts off and this is not due to a poorly calibrated display. If the display is off, just live with it. A replacement won't be any better,
 

Ebiker01

Active Member
May be also if the charger is not connected directly into outlet.
When i have the charger into a surge protector with 2-3other devices(heater/ monitor, etc) the charger gives me issues also.
 

Thomas Jaszewski

Well-Known Member
It clearly reads 48V battery.

GREAT JOB on providing information!

As Harry mentions, only a multimeter or wattmeter will give an accurate voltage. Browneye's idea might also be a solution. I your settings are for a 52V battery.

In the end an inexpensive multimeter is the best tool for trouble shooting many eBike issues.
 

dodjaki

New Member
Bravo ! Bravo !
rich c, Thomas Jaszweski, Browneye, HarryS, Ebiker01
And thank you !
To rich c and Thomas Jaszweski :
Indeed, the multimiter voltage is 54.4 V
To Browneye :
Checked display settings for voltage: it’s 48 V , my battery is 48V
Battery lead after full charge is 54.4 V ( i.e., “errant value on display “ - thanks Browneye !
Indeed , my “48V charger doesn’t peak a 52V battery to it’s near 60V capacity “ ( thanks again Browneye ! )
To HarryS :
“Voltmeter on battery terminals is 54.4 V
Indeed like you say : “ 48V battery is 54.6V at full charge and can be run down to 40 - 42V “ thanks HarryS, useful lesson for me.I Iearn from you HarryS that the capacity is not linear : 85% means 52.3V ect... like you say : “ percentage on display has secondary value ( sometimes misleading )
The charger is indeed 54.6V at no load voltage.
also HarryS, thanks for your insight :
Quoting you : “a brand new battery might be a little low ... if I run it down , recharge it, it should hit its max after two or three cycles.
like you say : “ I would just live with a display that is off “
To Ebiker01 :
The charger is connected directly to outlet.
to Thomas Jaszweski :
My settings is set for 48V battery.
You guys are tremendous brains.
Wow !
Infinitely grateful for your help !
You made my new biking life !