After charging my 48V accu with a 54V charger untill the display shows it is full and if I than switch the Voltage setting in the display from 48V to 54V the display shows the battery is half full. What will happen if I keep charging the battery while the display setting is still at 54 V ???? Will eventually the battery end up with 54 volts or is there a chance that the battery explodes ??
charging a battery at a different voltage setting in the display
- Thread starter Cees
- Start date
wturber
1 MW
I don't know what your are using to determine "full." I also don't know what the output voltage of your 54 volt charger is. If it is 54 volts, then it is really a 48 volt charger since 54.6 volts would be the correct charge voltage for a 13s a.k.a 48v lithium batter pack.
So, check the charger's output voltage. It should be about 54.6 volts and a little bit less is probably better.
Check the battery voltage when the charger tells you you have a full charge. The battery should read right about 54 volts when fully charged, If it reads more, then you are overcharging it and probably causing some damage. If the voltage is less than 54 volts, then you have more room to continue charging. And, of course, if it is at 54 volts you are pretty much fully charged.
So, check the charger's output voltage. It should be about 54.6 volts and a little bit less is probably better.
Check the battery voltage when the charger tells you you have a full charge. The battery should read right about 54 volts when fully charged, If it reads more, then you are overcharging it and probably causing some damage. If the voltage is less than 54 volts, then you have more room to continue charging. And, of course, if it is at 54 volts you are pretty much fully charged.
Yes, to get maximum capacity but without overcharging, you need to define your "daily usage Full" 100% with an ammeter at charge termination.
For bank longevity, that will be a few % lower than what the battery mfg specs say. Not just lower voltage, but not holding CV stage so long, depends on charging C-rate also.
Never trust charge sources or dumb displays to tell you, they will be inaccurate most of the time.
For bank longevity, that will be a few % lower than what the battery mfg specs say. Not just lower voltage, but not holding CV stage so long, depends on charging C-rate also.
Never trust charge sources or dumb displays to tell you, they will be inaccurate most of the time.
My battery is 48 V/12 Ah and the charger is a 54,6 V and 2 A.
With display I meant the C965 display and not the level indicators leds at the battery.
I guess if the indicator at the charger changes from red to green the charging process stops and the 48 V has been achieved, so the battery is full, right ??
With display I meant the C965 display and not the level indicators leds at the battery.
I guess if the indicator at the charger changes from red to green the charging process stops and the 48 V has been achieved, so the battery is full, right ??
wturber
1 MW
Cees said:
Maybe. We don't know what exactly the charger is doing and most of us don't trust single indicator lights.
The simple thing is to check the battery voltage after the charger changes from red to green. If it is at or very near 54.6, then yes your battery is fully charged or at least close enough. But regular monitoring of voltage and amps drawn and charged is a better way to know what is going on with your battery. Monitoring just voltage works very well also - especially if you also monitored amps for a while and have established the battery's voltage pattern during and after rides.
I keep an ammeter on my bike that tells me the amp hours, watt hours, current voltage, current amps, and current wattage. It shoes this when riding as well as when charging. It is probably more information than is necessary, but I figure this gives me a better chance of spotting a problem with the battery, charger, or bike motor than not having the info.
In this picture, the battery is nearing full charge and we know this because the battery icon shows that, the voltage is nearly 42 volts (36 volt battery), and the charge rate is 2.8 amps (negative is charge, positive is discharge). If the battery was at a lower charge state the amps would be closer to 8, the watts closer to 300 the voltage would be lower, and the battery icon would probably not be "full".
Again,Cees said:
>never trust charge sources or dumb displays to tell you about your charging process, they will be inaccurate most of the time.
"48V" as a descriptor does not necessarily translate directly to a precise termination voltage (Absorb / CV ) setpoint.
If your batt mfg spec is (and you want to push all the way to) 4.2Vpc, and
your bank is 13S, that does indeed mean your CV setpoint would be 54.6V. But IMO those three "ifs" should be confirmed, not assumed.
At 2A charge rate or .17C, you would not need to hold Absorb for long. In fact longevity would be better if you "just stop at" 54.6V, might be sacrificing 3-5% of actual range, possible less.
To cram every last Ah into the pack, your charger may stop where trailing amps tapers down to say 1A, holding past that would be pushing it.
That is what defines 100% Full, and you need a known good ammeter - which will include a voltmeter - to confirm the charger is doing its job.
Stopping a bit earlier is fine for longevity, but going on much longer is overcharging, stressing the pack with heat to no purpose and possibly dangerous.
