Battery not charging to 100%. Seeing three different charge readings

[McQ MT]

What I have : Jumbo Shark 48V 17.5 AH/48 V UY 240 Smart Charger/500C Bafang Display set for 48V
I have approx 20 hours of ride time on this battery
When I attempt to charge to 100% the charger stops and displays 54.7 v as if 100% while the volt meter reads 54.3, then display shows 53.9 or 70%?(should be 90%?) Considering conditions, riding style and the range I'm getting I am inclined to think that the display reading is correct in that I can only charge this battery to 70%. I have drained the battery and attempted to charge to 100% a few times. I purchased the battery from e bike essentials and charger/BBSHD from Luna. When I explained my issue of not getting a full charge into their battery, e bike essentials told me it was due to not having purchased the charger and BBSHD motor from them which would have all been calibrated to their battery and would give me a full charge. They didn't have a smart charger at the time I was purchasing the battery so I got it elsewhere. I have no idea if what they are saying is true. If so I would have purchased charger and battery from the same supplier. Essentials did not offer to sell me a more "compatible" charger instead they were just scornful. Does anyone know if I just need to get a different charger or perhaps balance the battery? Is it possible to calibrate a charger ? Thanks for feedback/strategies to get more juice into this battery

 

[Deleted member 4845]

Impressive. You managed to deal with two seperate bad dealers on one transaction.

You say you have a "48v" battery, meaning 12S, or 50.4V, then indicate you actually have a 13S. or 54.6V, which should NEVER, EVER actually get to 54.7.

There is no such animal as "calibrating to their battery", you do need to know the difference between 12S, 13S, and 14S, and your chemistry, but there are no brand-based variations.

If you actually do have a 12S, 50.4V battery then your actions are extremely dangerous and GET IT OUT OF THE HOUSE NOW!!!!!

If you do not post again we will assume your house burned to the ground and you with it.

 

[McQ MT]

Consumers need to identify and confirm 12s or 13s or 14s of the branded battery they purchased to know they are safe from catastrophe?? I'm not building a battery (or taking one apart) ; I'm charging a 48V 17.5 Ah battery with a 48V charger and riding my bike

 

[Deleted member 4845]

Yes, they absolutely do.

IF you purchase a 48V battery, you MUST HAVE a 48V charger, which will charge to NO HIGHER THAN 50.4V.

You have at least two and possibly three meters showing a charge of 53-54V. Including one at or more than 54.6, the max charge for a 52V battery. A 52V charger would do this.

You bought battery and charger from two different places with no complete understanding of exactly what you have.

You have created an extreme fire hazard, and severely damaged an expensive battery.

If it were in my home, it would be in the front yard IMMEDIATELY. Inside a bbq grill.

 

[McQ MT]

Yes, they absolutely do.

IF you purchase a 48V battery, you MUST HAVE a 48V charger, which will charge to NO HIGHER THAN 50.4V.

You have at least two and possibly three meters showing a charge of 53-54V. Including one at or more than 54.6, the max charge for a 52V battery. A 52V charger would do this.

You bought battery and charger from two different places with no complete understanding of exactly what you have.

You have created an extreme fire hazard, and severely damaged an expensive battery.

If it were in my home, it would be in the front yard IMMEDIATELY. Inside a bbq grill.

I have created a fire hazard by purchasing a branded LG 48 V battery and branded 48 V charger? Nothing you're writing is helpful at all. Can anyone provide some common sense to this ?

 

[McQ MT]

Yes, they absolutely do.

IF you purchase a 48V battery, you MUST HAVE a 48V charger, which will charge to NO HIGHER THAN 50.4V.

You have at least two and possibly three meters showing a charge of 53-54V. Including one at or more than 54.6, the max charge for a 52V battery. A 52V charger would do this.

You bought battery and charger from two different places with no complete understanding of exactly what you have.

You have created an extreme fire hazard, and severely damaged an expensive battery.

If it were in my home, it would be in the front yard IMMEDIATELY. Inside a bbq grill.

Nonsense, you're confused. . A 48v battery is @ 100% when charged to 54.6. Your 50.4 v claim would be approx 68% for a 48v battery.

 

[Deleted member 4845]

Good luck to you.

 

[Deleted member 4845]

It is one thing to be delusional and ignorant, but this is DANGEROUS delusional ignorance.

 

[McQ MT]

One more try here for you. If you can't know this most basic info below then you shouldn't be criticizing anyone.

48 V Percentage to Voltage chart is as follows
100% =54.6 v
90% =53.0 v
80% =52.1 v
70% =50.7 v
60% =49.6 v

Do you still think a 48 v battery cannot be charged past 50.4 v??

 

[Deleted member 4845]

So,tell me, what do you think the numbers are for a 52V battery, and how many decades of experience do you have and how many dozens of people with more experience than that have you spoken with?

Yours is the kind of stupidity that gets people killed.

12S
12 x 4.2

This is not my opinion. This is well-established fact.

 

[justaguy]

One more try here for you. If you can't know this most basic info below then you shouldn't be criticizing anyone.

48 V Percentage to Voltage chart is as follows
100% =54.6 v
90% =53.0 v
80% =52.1 v
70% =50.7 v
60% =49.6 v

Do you still think a 48 v battery cannot be charged past 50.4 v??

Exactly right, It says right on the back of the 48 volt charger that the output volts are 54.6 v a 48v battery that won't charge to 54.6 has lost capacity.

 

[addertooth]

And now for another confusing opinion.
I have a 13S battery. My terminal fully charged voltage (while on the charger is 54.6 Volts D.C. As measured by a Fluke 87 series V meter, which is calibrated.
It is sold as a 48v battery.
Once the battery is disconnected from the charger a few minutes, it dips down to 54.5 Volts D.C.

Decoding the S and P. Most batteries are Series AND Parallel. In the case of my 22.4 AH battery, It is a Lithium Ion battery, which groups 5 cells in Parallel, and then puts 13 of those "groups" in series. At a fully charged cell voltage of 4.2 Volts D.C., it provides the voltage I listed above.

Like all batteries, the greater the Load (in Amps) the battery is under, the greater the "dip" in voltage will be measured.
The numbers we are speaking above are essentially "no-load voltages".
This is why you will often see a battery recover a "bar" after it has rested after a ride.

In my opinion, the displayed voltage on the charger has an error which makes it look too high.
In my opinion, the percentage on your display probably has an error which makes it display too low.
It could be because your Display is currently set for a 52 Volt battery.
Ultimately, if you have Lithium Ion cells, and they are 13S configuration, trust your multimeter.
If your cells are LiFePO4, then the math changes. They have a different peak cell voltage.