Charger watt consumption

[Les]

I’ve a Renogy 3000watt inverter and 75amp battery charger combined you can adjust amps charging from 25amps to 75amps does any one know what wattage they would use at 75 and 25amps don’t want to overload site electrics.
Thanks Les

 

[activecampers]

Confused.
You have a battery bank with a 3000w inverter and want to connect a battery charger (of 25-75A) - to charge what?
Seems you are flattening one battery back to charge another and converting DC to AC back to DC with various inefficiencies. What are you trying to do exactly?

but to answer your question, if your 25-75A charger is to charge 12v then just multiply the numbers up and add some (as 12v charger may be 25A @ 14v rather than 12v, devil is in the spec sheet)

so 25A @ 12v is 300W (say 350-400 realistically) and 75A is 3x that, so 900W (say 1000-1100W max).

But not sure how this relates to site electrics?

If you were on 6A hookup (say) - @220v = 1300W (multiply 6x220) So you could use a 75A charger (1100w) to top up your battery bank whilst using you inverter but thats irrelevant.

If you were on 3A hookup (750W) you'd need to use a lower charge rate (maybe 50A ) etc.

But all meaningless without more info

 

[Lenny HB]

I take it you have an inverter charger, charging at 75 amps will take approx 4 amps from the EHU

 

[Les]

Confused.
You have a battery bank with a 3000w inverter and want to connect a battery charger (of 25-75A) - to charge what?
Seems you are flattening one battery back to charge another and converting DC to AC back to DC with various inefficiencies. What are you trying to do exactly?

but to answer your question, if your 25-75A charger is to charge 12v then just multiply the numbers up and add some (as 12v charger may be 25A @ 14v rather than 12v, devil is in the spec sheet)

so 25A @ 12v is 300W (say 350-400 realistically) and 75A is 3x that, so 900W (say 1000-1100W max).

But not sure how this relates to site electrics?

If you were on 6A hookup (say) - @220v = 1300W (multiply 6x220) So you could use a 75A charger (1100w) to top up your battery bank whilst using you inverter but thats irrelevant.

If you were on 3A hookup (750W) you'd need to use a lower charge rate (maybe 50A ) etc.

But all meaningless without more info

No I’m charging from mains power to top a 314amp Lithium battery.i had a bit of a saga installing inverter/charger now in France it was doing funny things,you have to have I/C switched on as the van ring was connected to inverter output as inverter decides what output to use.
I have now disconnected the van ring from inverter so mains run ring,also I’ve got power going to inverter/charger so it just charges battery.
I’ve decided now may just wire inverter to a separate double socket so that’s the only of grid power.
Hope that makes some sense so when I’ve charger on the wired inverter socket will be on
Les

 

[matbic]

This might help:

I_charge_max_setting = (I_EHUlimit × V_mains × η × PF) / V_batt

I_charge_max_setting = current to set on charger
I_EHUlimit = current rating of campsite socket
V_mains = mains voltage
η = charger efficiency
PF = power factor of charger
V_bat = battery voltage

You might have to look some of these up but here are some defaults that won’t be far out.

V_mains = 220, this allows for the loss of voltage in a normal badly wired up camp site (i have seen it at 180v but that is really getting dangerous!)
η = 0.85 might be a bit higher but check on data sheet of charger
PF = new charger will be in region of 0.9
V_bat = 14.4, this is the voltage when charger is in the absorption stage

So something like this will be a good estimate:
simplify I_charge_max_setting = (I_EHUlimit × 220 × 0.85 × 0.9) / 14.4
which is:

I_charge_max ≈ 11.7 × I_EHUlimit

I guess setting charger limit to 10 times ehu breaker limit will be safe.

Hope this helps

 

[Les]

No I’m charging from mains power to top a 314amp Lithium battery.i had a bit of a saga installing inverter/charger now in France it was doing funny things,you have to have I/C switched on as the van ring was connected to inverter output as inverter decides what output to use.
I have now disconnected the van ring from inverter so mains run ring,also I’ve got power going to inverter/charger so it just charges battery.
I’ve decided now may just wire inverter to a separate double socket so that’s the only of grid power.
Hope that makes some sense so when I’ve charger on the wired inverter socket will be on
Les