48 Volt (13S) Battery Voltage Chart - Li-Ion Batteries

48 Volt (13S) Battery Voltage Chart - Li-Ion Batteries

Anton

Admin
Staff member
Local time
3:51 AM
Joined
Jun 16, 2018
Messages
742
Location
Australia
A 48v battery is fully charged at 54.6v. The low voltage cutoff is around 39v. It is best not to discharge more than 80% of the capacity for good cycle life. 80% DOD is around 43v depending on cell chemistry. Li-ion has a flat discharge curve. The voltage will drop from 54.6v down to 50v fairly quickly then level off. Below 42v the voltage drops off quickly and there is not much remaining capacity left. The cells heat up at this point as well.

48 Volt Nominal Voltage Chart for Ebike Batteries.jpg


48 Volt Discharge Curve for Ebike Batteries.jpg
 
Good information. I have two eBikes. One has 52V batteries and the other has 48V batteries. Does anyone have a similar chart they can post for 52V batteries?
 
Good information. I have two eBikes. One has 52V batteries and the other has 48V batteries. Does anyone have a similar chart they can post for 52V batteries?
Here ya go.....

 
A 48v battery is fully charged at 54.6v. The low voltage cutoff is around 39v. It is best not to discharge more than 80% of the capacity for good cycle life. 80% DOD is around 43v depending on cell chemistry. Li-ion has a flat discharge curve. The voltage will drop from 54.6v down to 50v fairly quickly then level off. Below 42v the voltage drops off quickly and there is not much remaining capacity left. The cells heat up at this point as well.

View attachment 419

View attachment 418
I have recently purchased two 48v ebikes. When the charge is complete (green light on) I have checked the voltage on the display and on both bikes it reads 53.4v.
The chargers that came with the bikes say they are 54.6v and 2amp...

I am a bit confused as I have read and seen numerous charts that 54.6v is 100% charge on 48v ebike batterys, yet I see the chart above that indicates 53v is 100% charge which corresponds with my ebike readings.

Any clarification would be helpful...

Thanks!
 
I have recently purchased two 48v ebikes. When the charge is complete (green light on) I have checked the voltage on the display and on both bikes it reads 53.4v.
The chargers that came with the bikes say they are 54.6v and 2amp...

I am a bit confused as I have read and seen numerous charts that 54.6v is 100% charge on 48v ebike batterys, yet I see the chart above that indicates 53v is 100% charge which corresponds with my ebike readings.

Any clarification would be helpful...

Thanks!
48 V is the nominal voltage. The actual battery voltage will vary depending on state of charge and what its load is at that moment.

As you noticed a 48 V battery at full charge with no load is more like 53 V.

If your display will show instantaneous voltage, you will see it sag down when you give it some throttle, then it comes back up when the load is removed.

Example: I was out riding my 52 V-rated eMoped last night. It was at around 54 V when I left, so not quite fully charged. When I hit the throttle, I noticed it sag down to around 49 V. I didn't notice the no-load voltage when I was done with the ride.

Anton provided some voltage charts that correlate state-of-charge with no-load voltage measurements; search them up if you're curious.
 
I have recently purchased two 48v ebikes. When the charge is complete (green light on) I have checked the voltage on the display and on both bikes it reads 53.4v.
The chargers that came with the bikes say they are 54.6v and 2amp...

I am a bit confused as I have read and seen numerous charts that 54.6v is 100% charge on 48v ebike batterys, yet I see the chart above that indicates 53v is 100% charge which corresponds with my ebike readings.

Any clarification would be helpful...

Thanks!

Have a look at my other 48V battery chart here which shows 54.6V as 100%: https://ebikesforum.com/resources/48-volt-13s-battery-voltage-chart-li-ion-batteries.37/

Calculation: 13 Cells x 4.2 Volts/Cell = 54.6 Volts Fully Charged

Assumptions: Your pack uses typical 18650 cells which charge to 4.2V and discharge to 3.0V.
 
Hi All,

Very insightful information....

Regarding the link... it says to place a timer to prevent overcharging the battery....will a timer be need if the battery has a bms?
The battery should have a BMS, but a charger should also programmed to behave like a charger, rather than just a power supply:
  1. Constant current mode until a threshold voltage is reached (ex. 54.6 V for a 48 V battery pack)
  2. When threshold voltage is reached, change to constant voltage mode, which reduces charge current accordingly
  3. When charge current falls below a certain level, stop charging and indicate appropriately.
Many tricky people like to use a power supply to charge; in that case, the charge current will never stop; it will trickle charge the battery forever. (if the battery BMS is not smart enough to turn off charging) This will either reduce the life of the pack or possibly create a hazard.

In the case of using a power supply or LED driver to charge batteries, a timer is a necessary safety feature.
 
The battery should have a BMS, but a charger should also programmed to behave like a charger, rather than just a power supply:
  1. Constant current mode until a threshold voltage is reached (ex. 54.6 V for a 48 V battery pack)
  2. When threshold voltage is reached, change to constant voltage mode, which reduces charge current accordingly
  3. When charge current falls below a certain level, stop charging and indicate appropriately.
Many tricky people like to use a power supply to charge; in that case, the charge current will never stop; it will trickle charge the battery forever. (if the battery BMS is not smart enough to turn off charging) This will either reduce the life of the pack or possibly create a hazard.

In the case of using a power supply or LED driver to charge batteries, a timer is a necessary safety feature.
What about the chargers that come standard when you buy an electric scooter? In my opinion, they seem pretty straightforward—you just plug them in and let them do their job. For example, my charger is for a 48-volt battery, and the maximum output is around 54.6 volts. I don't have my charger with me right now, but I believe it has an amp output of 2 amps.

Are these chargers considered "smart chargers" or are they "dumb chargers" that just keep pushing out voltage and amps non-stop? I’ve noticed that my charger has a light that turns red when it detects the battery needs charging, and once it reaches the 54.6 volts, the light turns green. This indicates to me that the battery is fully charged.

So, are these standard chargers smart chargers like the ones you mentioned, or dump charger, are they just simple power supplies, like the pic?

1717712656553.png


I'm new to electric scooters and just trying to understand how everything works
 
Many tricky people like to use a power supply to charge; in that case, the charge current will never stop; it will trickle charge the battery forever. (if the battery BMS is not smart enough to turn off charging)
All of the power supplies I have ever seen or used support both CC+CV modes. They taper off and stop exactly like the three steps you listed.

I used the Wanptek 60v model, based on a recommendation from someone I trusted who had taken one apart and examined its innards and found it to be of good quality, but two of the three I bought have since died. If you look at their advertising, they do not specify CC+CV mode support, but it was built in and you can see the little lights on the display that will switch on their own from CC to CV as voltage approaches the set target. Still, I don't recommend them given their long term unreliability.

PXL_20220430_002911987.jpg


Thats no mistake, the charger was really set to charge at 0.20a. This was a pic to establish a baseline while I timed the charge to see how much voltage was added in an hour at that charge rate. From doing stuff like that I was able to figure out the slowest charge rate for a routine down time.

What I do recommend are the Mean Wells, which are in wide use as probably the best quality 'smart charger' you can lay your hands on in the marketplace. That includes the Cycle Satiator, which itself is effectively a tarted up CC+CV LED power supply, that has had a brain added with a GUI to set, store and select multiple profiles. The thing is the Mean Wells are a bit simpler, more durable and a lot cheaper.


^^^ I wrote that in 2019, had been using the Mean Wells for at least a year at that point and since then still no failures.
 
All of the power supplies I have ever seen or used support both CC+CV modes. They taper off and stop exactly like the three steps you listed.

I used the Wanptek 60v model, based on a recommendation from someone I trusted who had taken one apart and examined its innards and found it to be of good quality, but two of the three I bought have since died. If you look at their advertising, they do not specify CC+CV mode support, but it was built in and you can see the little lights on the display that will switch on their own from CC to CV as voltage approaches the set target. Still, I don't recommend them given their long term unreliability.

Thats no mistake, the charger was really set to charge at 0.20a. This was a pic to establish a baseline while I timed the charge to see how much voltage was added in an hour at that charge rate. From doing stuff like that I was able to figure out the slowest charge rate for a routine down time.

View attachment 14836

What I do recommend are the Mean Wells, which are in wide use as probably the best quality 'smart charger' you can lay your hands on in the marketplace. That includes the Cycle Satiator, which itself is effectively a tarted up CC+CV LED power supply, that has had a brain added with a GUI to set, store and select multiple profiles. The thing is the Mean Wells are a bit simpler, more durable and a lot cheaper.


^^^ I wrote that in 2019, had been using the Mean Wells for at least a year at that point and since then still no failures.
Hey I just read your comment and looking into purchasing a Mean Well but an new to the market and was wondering if there's a specific model for my Wired freedom? I read there's two different options ...the LRS and RS power supply, which one is better??
 
Hey I just read your comment and looking into purchasing a Mean Well but an new to the market and was wondering if there's a specific model for my Wired freedom? I read there's two different options ...the LRS and RS power supply, which one is better??

I recommended specific models in that linked article, with differing current levels going up into the stratosphere. The 480w model is a 6 lb boat anchor but on an adventure bike where I am plugging in out in the boondocks to charge a 32ah battery, and need to get home before the tide comes in and closes down the way home, being able to pump in 8 amps makes some sense.

If your Wired Freedom is a 60v system, it won't work. A 60v system peaks at 67.2v and thats more than any of the Mean Well HLG series can output. LRS series doesn't go past 48v systems. I see no RS series. Spec sheets on their entire product line are here:

Look thru that rather long list to see if there is something that works. But be careful. The HLG line detailed in my article is the only one I am aware of that sees widespread use in the DIY community.

Their NPP series dedicated chargers look to only be compatible with lead-acid chemistry. What I am using is an LED power supply that supports CC+CV modes (which in layman's terms is 'smart charging').

Anything on the Mean Well List with an 'H' at the front of its name appears to stand for 'harsh' which are the potted, IP65-rated models.

I personally standardized on 52v/14S systems across all my bikes and this makes life a lot simpler sharing chargers and whatnot..
 
Have a look at my other 48V battery chart here which shows 54.6V as 100%: https://ebikesforum.com/resources/48-volt-13s-battery-voltage-chart-li-ion-batteries.37/

Calculation: 13 Cells x 4.2 Volts/Cell = 54.6 Volts Fully Charged

Assumptions: Your pack uses typical 18650 cells which charge to 4.2V and discharge to 3.0V.
That chart you originally posted originated at Luna Cycles. They published it for a time on their web site years ago. But as you noted, its inaccurate. In fact all of them were inaccurate (they created others for different voltages) and I was told by Luna tech support they had to withdraw them because of all the questions and complaints they generated. I *think* they did what they did to offer a conservative level of advice.

A few years ago I did replacements that show the correct voltages (using essentially the same assumption you do), show the calculation method for each voltage (36v thru 72v) in 1% increments, as well as individual cell voltages at each step. Also on 36v, 48v and 52v charts there is a column for usable volts remaining at each step.

 
All of the power supplies I have ever seen or used support both CC+CV modes. They taper off and stop exactly like the three steps you listed.

I used the Wanptek 60v model, based on a recommendation from someone I trusted who had taken one apart and examined its innards and found it to be of good quality, but two of the three I bought have since died. If you look at their advertising, they do not specify CC+CV mode support, but it was built in and you can see the little lights on the display that will switch on their own from CC to CV as voltage approaches the set target. Still, I don't recommend them given their long term unreliability.

View attachment 14836

Thats no mistake, the charger was really set to charge at 0.20a. This was a pic to establish a baseline while I timed the charge to see how much voltage was added in an hour at that charge rate. From doing stuff like that I was able to figure out the slowest charge rate for a routine down time.

What I do recommend are the Mean Wells, which are in wide use as probably the best quality 'smart charger' you can lay your hands on in the marketplace. That includes the Cycle Satiator, which itself is effectively a tarted up CC+CV LED power supply, that has had a brain added with a GUI to set, store and select multiple profiles. The thing is the Mean Wells are a bit simpler, more durable and a lot cheaper.


^^^ I wrote that in 2019, had been using the Mean Wells for at least a year at that point and since then still no failures.
I’m familiar with Mean Well power supplies from my UL days. They are indeed good quality, as you say.

HOWEVER… the ones you mention are LED drivers, which don’t shut down charge current ever, because they think they’re supplying LEDs, rather than charging Li-Ion batteries. You use a timer, so it’s OK, but be careful about advising newbies to use them.

Switching to constant voltage mode and trickle-charging forever is going to wreck some battery packs, over time.
 
I’m familiar with Mean Well power supplies from my UL days. They are indeed good quality, as you say.

HOWEVER… the ones you mention are LED drivers, which don’t shut down charge current ever, because they think they’re supplying LEDs, rather than charging Li-Ion batteries. You use a timer, so it’s OK, but be careful about advising newbies to use them.

Switching to constant voltage mode and trickle-charging forever is going to wreck some battery packs, over time.
No they shut completely off once they reach target voltage. Sure they trickle in a little more if voltage drops (wouldn't a standard-issue charger do this?), but they do drop to zero. I keep a meter on them and you can monitor that in real time. Also remember these are in common use as ebike chargers and much smarter people than I on the subject (Endless Sphere) recommend them. I got the idea from one of the staff on the Luna ebike forum, who pointed me to E-S for the threads on its use. Myself I have been using them constantly since I think 2018 on daily-driven bikes, where often I charge 2x daily. Once at work and once when I get home.

On the surface, as a layman, I'm thinking 0.0a of power delivered is all that matters. Or is there some effect that manifests itself if you leave it on say for a week or a day or something? To me the purpose of an adjustable charger is to adjust it so the charge isn't any faster than it needs to be, ergo the charger isn't going to sit powered at target voltage for long (I'm ignoring the timer that forces the issue separately).

And remember... the much-vaunted Cycle Satiator 'charger' is the same thing with a coat of paint and lipstick. Behaves in exactly the same way as a Mean Well.
 
Back
Top