12 Volt/24 volt charging confusion!!!!

[e trouble]

Would be happy to hear how my 12 volt Li Time charger can charge my 12 volt lithium 200ah battery at 40 amps plugged into a 15 amp circuit yet tech support at SRNE is telling me I need to connect my all in one 48 volt system to a 40 amp circuit to charge my SOK 48 volt 100 ah battery?
Could have bought another 12 volt for what it's going to cost on just for 8 feet 8/2 and breaker.
All opinions appreciated.

 

[SunDave]

Would be happy to hear how my 12 volt Li Time charger can charge my 12 volt lithium 200ah battery at 40 amps plugged into a 15 amp circuit yet tech support at SRNE is telling me I need to connect my all in one 48 volt system to a 40 amp circuit to charge my SOK 48 volt 100 ah battery?
Could have bought another 12 volt for what it's going to cost on just for 8 feet 8/2 and breaker.
All opinions appreciated.

Hi e trouble.

It's just a matter of realizing what voltage the amps apply to. In this case it would be 40 amps at 12v, or 480 watts. Charging your 48v battery at 40 amps takes over 2000 watts, so cannot be done with a standard 15 amp outlet.

40x12=480

40x48=1920

Real world is higher wattage since they charge at higher voltages than that (slightly). Also you can only pull 80% of your rating on a circuit, so that is a limiting factor as well. Does that help?

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If you don't need to charge it that fast, I'm sure you can find a charger that wouldn't require a larger circuit. Some members here may have recommendations.

 

[Brucey]

Would be happy to hear how my 12 volt Li Time charger can charge my 12 volt lithium 200ah battery at 40 amps plugged into a 15 amp circuit yet tech support at SRNE is telling me I need to connect my all in one 48 volt system to a 40 amp circuit to charge my SOK 48 volt 100 ah battery?
Could have bought another 12 volt for what it's going to cost on just for 8 feet 8/2 and breaker.
All opinions appreciated.

14V*40A=560W
56V*40A=2240W

 

[SunDave]

I can also add, that the volt/amp calculations apply to your battery as well. For example, your 12v 200 amp hour battery has 1/2 the capacity of your 48v 100 amp hour battery. You just take the voltage, times the amp hours to come up with watt/hours.

 

[e trouble]

Hi e trouble.

It's just a matter of realizing what voltage the amps apply to. In this case it would be 40 amps at 12v, or 480 watts. Charging your 48v battery at 40 amps takes over 2000 watts, so cannot be done with a standard 15 amp outlet.

40x12=480

40x48=1920

Real world is higher wattage since they charge at higher voltages than that (slightly). Also you can only pull 80% of your rating on a circuit, so that is a limiting factor as well. Does that help?

--------------

If you don't need to charge it that fast, I'm sure you can find a charger that wouldn't require a larger circuit. Some members here may have recommendations.

Thanks much clearer now. So does that mean I should be able to get away with a 20 amp breaker?
20*120=2400

 

[740GLE]

Does the charger inverter allow you to throttle back charging via programming?

Say dial it back from 40a down to 30a or 20a and stay on a 15a circuit?

 

[e trouble]

Yes exactly. I have a 20 amp breaker on a #12 conductor and works well with 20 set in parameter but kicks off at 30.
Hoping that going to #10 conductor will get me there.
Have no experience charging lithium battery and purchased a kit so I was trying to run it at the 60 Amp default setting.
What's your opinion on the amount of charging amperage for safety and battery longevity ?

 

[SunDave]

Hi,
If you look at it this way, the 20 amp setting (assuming battery amps) would be charging at about 53 volts times 20 amps. 1060 watts/hr. That would charge your battery from 20% to 100% in roughly 4 hours.

100 amp hour battery, at 20 per hour.

Depends what kind of speed you need, but for a backup situation, that seems plenty fast to me. If I charge my batteries by generator (it's usually by solar), I charge at about that rate.

Again, leave some slack. Don't try to use the full amperage of your breaker. The 1000 watts through a 12-gauge conductor is within reason.

 

[SunDave]

works well with 20 set in parameter but kicks off at 30.

You may also want to check if your manual specifies what that amperage applies to. The battery amperage or the supply circuit amperage. Always good to read and re-read to be safe.

 

[Steve777]

Another consideration: looks like your SRNE AIO can pass AC thru to the connected loads too. Up to 63A if I am reading the label you posted correctly. So unless you have disabled that, or limited the amount of AC pass thru to the loads when there is no solar and the battery does not have enough power left to run things, you would likely over-draw a 20A breaker on AC input to the AIO, no?

 

[time2roll]

No harm in slow charging the battery. What is the rush?

 

[e trouble]

Thanks everyone you have no idea how much you have helped this old brain of mine. Glad I figured out how to somewhat use this cell phone.
Curious to know why my original main board has 2 of these things my finger is pointing to when replacement board has 1 and a blue plastic box thingy. Also why original donut thing is tightly wound with very fine copper wire and replacement is looser wound with large copper wire.