Outback VFX3524 Charging Issue

northerner

I'm having an issue with the charging of the batteries through my inverter (Outback VFX3524), where charging current to the batteries while running a generator maxes out at about 54 amps (24vdc output to batteries). It should be capable of 82 amps according to the spec sheet. Is there another setting which determines the charging limit that perhaps I've missed? The only limit which I have set is the AC input from the generator, and I currently have that set to 20 amps at 120 vac in. Loads are not an issue in this case, as I've checked it with very light loads (less than 100 watts). Also the generator puts out far more than what the charging limit indicates, which shows up when heavy loads do come on. Any ideas?

jcheil

Re: Outback VFX3524 Charging Issue

If you are saying that you are limiting the AC from the generator to the charger at 20amps, then 54amps on the DC side is pretty much on the upper end of what you could expect from only 20a on the AC side.

My stand alone charger 40a charger just barely runs on a 20amp AC circuit (however your charger is way more efficient).

Cariboocoot

Re: Outback VFX3524 Charging Issue

There are two settings: the Gen Input Limit and the Max Charge Current.
The input limit is set to keep the combination of loads and charge demands from exceeding the gen's capacity. 20 Amps would be about 2.4 kW.
The maximum charge current is set under the charger menu and is in AC Amps even though you charge in DC Amps. It's about a 5 to 1 ratio: every 1 Amp AC = 5 Amps DC. If this is limiting you to 54/55 Amps then it's probably set at 11. The higher you set it, the less current available for loads. But it will reduce charging first, rather than drop AC OUT.

So if the gen input is at 20 Amps and the loads are pulling 9 Amps no matter what the maximum charge current is at it won't pull more than 11 Amps AC. (The numbers do not equate perfectly, nor are they 100% accurate.)

NorthGuy

Re: Outback VFX3524 Charging Issue

What is the battery voltage when this happens?

northerner

Re: Outback VFX3524 Charging Issue

jcheil wrote: »

If you are saying that you are limiting the AC from the generator to the charger at 20amps, then 54amps on the DC side is pretty much on the upper end of what you could expect from only 20a on the AC side.

My stand alone charger 40a charger just barely runs on a 20amp AC circuit (however your charger is way more efficient).

That's the max that this inverter will go to is 20 amp limit at 120 vac. It should be closer to 80 amps than 50. Specs are 82 amps?

northerner

Re: Outback VFX3524 Charging Issue

NorthGuy wrote: »

What is the battery voltage when this happens?

Between 27 and 28 volts, but doesn't make much difference.

NorthGuy

Re: Outback VFX3524 Charging Issue

northerner wrote: »

Between 27 and 28 volts, but doesn't make much difference.

First, this could be high enough to hit an absorb voltage setting.

Second, the more voltage the more power.

28V x 54A = 1512W. Discounting charger efficiency 1512W/0.85 = 1779W

If pf=1, this is 1779W/120V = 14.8A.

Bur, if pf=0.8, this is 18.5A. If it limits amps, not watts, then this is exactly your limit. Do you know what is the charger power factor?

Cariboocoot

Re: Outback VFX3524 Charging Issue

Don't mind me. I've just owned and used a VFX3524 for years. :roll:

northerner

Re: Outback VFX3524 Charging Issue

NorthGuy wrote: »

First, this could be high enough to hit an absorb voltage setting.

Second, the more voltage the more power.

28V x 54A = 1512W. Discounting charger efficiency 1512W/0.85 = 1779W

If pf=1, this is 1779W/120V = 14.8A.

Bur, if pf=0.8, this is 18.5A. If it limits amps, not watts, then this is exactly your limit. Do you know what is the charger power factor?

Absorb is set to 29.2 v, so not an issue there.

This inverter is listed as ~92% efficient. Also listed, is 82 amps DC continuous charger current. It's not anywhere close to that?

jcheil

Re: Outback VFX3524 Charging Issue

To get 82amps at 24vDC out of that you will need a rather large generator (5k+). What size do you have?
And pay attention to what coot said since he owns one. But it does sound like your settings are wrong.

northerner

Re: Outback VFX3524 Charging Issue

jcheil wrote: »

To get 82amps at 24vDC out of that you will need a rather large generator (5k+). What size do you have?
And pay attention to what coot said since he owns one. But it does sound like your settings are wrong.

Oh, sorry about that, I missed seeing his post, checking it out now.

northerner

Re: Outback VFX3524 Charging Issue

Cariboocoot wrote: »

There are two settings: the Gen Input Limit and the Max Charge Current.
The input limit is set to keep the combination of loads and charge demands from exceeding the gen's capacity. 20 Amps would be about 2.4 kW.
The maximum charge current is set under the charger menu and is in AC Amps even though you charge in DC Amps. It's about a 5 to 1 ratio: every 1 Amp AC = 5 Amps DC. If this is limiting you to 54/55 Amps then it's probably set at 11. The higher you set it, the less current available for loads. But it will reduce charging first, rather than drop AC OUT.

So if the gen input is at 20 Amps and the loads are pulling 9 Amps no matter what the maximum charge current is at it won't pull more than 11 Amps AC. (The numbers do not equate perfectly, nor are they 100% accurate.)

Thanks for that coot! I will check out the Max Charge current. Edit: just checked the max charge current and it's set to 20 amps as well. Loads don't factor in as I mentioned as I did the check when they were virtually non existent.

Blackcherry04

Re: Outback VFX3524 Charging Issue

northerner wrote: »

Thanks for that coot! I will check out the Max Charge current. Edit: just checked the max charge current and it's set to 20 amps as well. Loads don't factor in as I mentioned as I did the check when they were virtually non existent.

What INPUT are you using " Gen or Grid " ?? What Generator are you using to charge with ??

Cariboocoot

Re: Outback VFX3524 Charging Issue

northerner wrote: »

Thanks for that coot! I will check out the Max Charge current. Edit: just checked the max charge current and it's set to 20 amps as well. Loads don't factor in as I mentioned as I did the check when they were virtually non existent.

Okay, problem: the maximum charge current can not be 20 Amps AC as there is no such thing; it would be 100 Amps DC. Turn this down to the right number for your batteries. IIRC you have about 600 Amp hours so this should be 12 AAC.

northerner

Re: Outback VFX3524 Charging Issue

Blackcherry04 wrote: »

What INPUT are you using " Gen or Grid " ?? What Generator are you using to charge with ??

That may have been the problem as it was set to Grid. I didn't realize you could change this to Gen. And I wasn't in the right page when I set the charger limit, as it was at 13 amps. All is well now! Charging at close to 70 amps and showing 2100 watts charging power in. Using a Yamaha EF 3000i Thanks for all the help!!!

Blackcherry04

Re: Outback VFX3524 Charging Issue

northerner wrote: »

That may have been the problem as it was set to Grid. I didn't realize you could change this to Gen. Using a Yamaha EF 3000i

OK, just set the AC amps in to the max on the gen ( breaker ) and the Charger Limit to something under that. Using the wrong Input setting is common thing.

northerner

Re: Outback VFX3524 Charging Issue

Blackcherry04 wrote: »

OK, just set the AC amps in to the max on the gen ( breaker ) and the Charger Limit to something under that. Using the wrong Input setting is common thing.

I find their menu system rather confusing and awkward to navigate. Some of the settings have to be done in the Advanced menu as well.

NorthGuy

Re: Outback VFX3524 Charging Issue

northerner wrote: »

I find their menu system rather confusing and awkward to navigate. Some of the settings have to be done in the Advanced menu as well.

The important thing is that you can set what you want. It is better than something which is very smooth, bot doesn't let you configure things.

Blackcherry04

Re: Outback VFX3524 Charging Issue

northerner wrote: »

I find their menu system rather confusing and awkward to navigate. Some of the settings have to be done in the Advanced menu as well.

It looks like that they originally set them up where the Installer would set the settings and then the user would be locked out unless they had the password.


It's really a handy feature if you have two Generators of a different size, call one "Gen" and other "Grid" then all you have to do is change the input instead of the settings for each. I always forget to swap them at times though.

Cariboocoot

Re: Outback VFX3524 Charging Issue

The original purpose of the GRID/GEN AC IN selection was for system used as back-up power which might be fed by utility under normal circumstances or a generator during an extended outage. The two functions can in fact be used interchangeably, but you have to have the programming and input selection match the power source; if you program GEN for the generator specs but select GRID for input it may not be compatible.

Complicated? Yes, but they are the must versatile design around. Still.

northerner

Re: Outback VFX3524 Charging Issue

Blackcherry04 wrote: »

It looks like that they originally set them up where the Installer would set the settings and then the user would be locked out unless they had the password.


It's really a handy feature if you have two Generators of a different size, call one "Gen" and other "Grid" then all you have to do is change the input instead of the settings for each. I always forget to swap them at times though.

Yes, that could easily be accomplished with admin status, a simple log in/out to actual make certain changes. It would be best to have everything together IMO. A larger screen with all the headings listed or even something similar to the midnite classic display would be an improvement.

bill von novak

Re: Outback VFX3524 Charging Issue

Cariboocoot wrote: »

The two functions can in fact be used interchangeably, but you have to have the programming and input selection match the power source; if you program GEN for the generator specs but select GRID for input it may not be compatible.

If GEN is selected instead of GRID is the inverter more "lenient" in its requirements for accepting the power source?

Blackcherry04

Re: Outback VFX3524 Charging Issue

I have a Outback Wish list for Inverter / Chargers.

1) Ending Amps Feature
2) Forced Float with Timer Reset

Once you start a Charge cycle there is no way to get out of it unless you start a new Bulk cycle from the Hot Keys and then terminate it. Otherwise the Absorb timer will keep restarting the cycle where it left off because of the timer.

To get Ending amps I have to start a old Xantrex Inverter and let it finish the charge off, if i want it to be automatic.

Cariboocoot

Re: Outback VFX3524 Charging Issue

bill von novak wrote: »

If GEN is selected instead of GRID is the inverter more "lenient" in its requirements for accepting the power source?

Depends on how it's programmed. Basically two sets of the same criteria, one labeled "GRID" and one labeled "GEN". The default values on "GRID" have less latitude.