Inverter / Charger Settings when Batteries Removed & More

[Bronccat]

So, I have the house batteries and one of the engine batteries out because I am working on the tray. I am hooked to 50 amp Shore power. I turned the charger off on the magnum remote since the batteries were disconnected.


I noticed the lights were dim.

I hit the "charger on" button today and the heater fan sped up and the lights brightened.

So I assume the charger should be on even with batteries disconnected?

This is a magnum charger / inverter, inverter is on.

Here's a shot of the remote with charging on and charging off:







Also, I opened the battery compartment door the other day and the batteries were all overflowing. Haven't seen that since we got the coach in November.

I checked the electrolyte (about 1/4" over the plates), checked with hydrometer (all good). There was some corrosion in the tray which I was told during the checkout was due to off-gassing, but once I got the batteries out it was clear there was a lot of liquid escaping historically. Once I got the mat out of the bottom of the tray, there was a ton of corrosion and liquid under there. I have added mineral oil for the time being, but don't know if there is another issue. These are interstate, wet cell, workaholic.

Thanks in advance!

[twinboat]

You need to check the voltage setting of the charger portion of your inverter/charger.

Your absorb voltage seems high.

That and 10.3 volts is a dead battery. Going that low is damaging.

[bobmac]

If you take any of the batteries out, you need to disconnect the positive and negative leads feeding the battery bank. You also need to insure the circuits they feed are isolated by turning off the battery disconnect switches. If you take some of the house batteries out, you run the risk of a major short circuit of the remaining batteries if one of the positive connecting leads touches anything grounded such as the battery tray. Nothing in the coach should work if the batteries are properly disconnected. Don't turn on the charger as there are no batteries connected. You are lucky that you haven't had a major short with what you have described. I suggest you get a friend who is knowledgeable of and comfortable working with batteries. The consequences of a short can be damaging to both yourself and the other electrical components and could result in anything up to a fire that could consume the coach.

[Bronccat]

Thanks. I thought it only charged the house batteries and there aren't any house batteries connected. Even if it charged the engine batteries too, I'm pretty sure it reads the 10.3 even with the battery switch off. Not sure how that works.

[Bronccat]

I turned both switches off before disconnecting. I have turned the engine switch on only to lower the steps. As stated above all house batteries are out.

[Bronccat]

This (from the manual) reads like the inverter should be off and the charger should be on (except for the part about charging the batteries that aren't there):

• Inverter Mode:
Direct current (DC) from the motorhome batteries is transformed into alternating current (AC) for use with electrical appliances.

• Charger Mode:
Alternating current (AC) is taken directly from shore power (or other AC sources) and passed directly to your household appliances. At the same time, the incoming AC is also converted to DC to recharge the motor home batteries.

When both the INV and CHG LEDs are ON, the inverter is in standby mode. Shore or generator AC power is passed through the inverter to the loads. If shore or generator power is lost, the inverter automatically supplies AC power to the loads.

[Bronccat]

Correction to OP - Charger isn't "off" or "on" it's "stand-by" or "on"

[bobmac]

Bronccat
Couple of things to check:
Workaholic batteries are heavy duty commercial batteries and not true deep cycle batteries. If they have "overflowed" before, water has likely been added depleting the electrolyte in the battery. Sounds like they are in poor shape and may need replacement.
From your inverter panel pix, note the inverter and charger light are on in the first picture. I don't believe that unit can charge and invert simultaneously. Don't understand while both lights are on. The current shown is also excessive if neither of the batteries are connected - they are usually disconnected for the charger when the disconnect switch is on as you indicated.
The second picture indicates the inverter is working and is drawing significant current accounting for the 10.3 volts on the battery and your dim lights.
Don't think this is good news to hear but you might want to start by getting tte batteries tested to determine if replacement is required.

[Bronccat]

Thanks. I've contacted magnum to be safe.

The batteries are 7 years old so they are probably about shot.

[Bronccat]

Batteries say U2200UTL Deep Cycle, so I'm pretty sure they are Deep cycle...

[lbw6303]

Seems to me that the Inverter should run even if no house batt's present -- if there is a load somewhere in the coach. It normally takes AC voltage and "inverts" it to DC to run lights, etc and/or to charge house Batt's. it should provide some output if, for example, the lights are turned on. Those lights should get sourced from the inverter. On the other hand, if no house batt's, the 10.3v makes no sense, unless that's a standby output w/ no load on the inverter. If house batt's installed, inverter on standby it seems like the 10.3 volts would be indicating a failed batt/batt's. That could explain "boiling over". The charger is trying to literally DRAG a failed battery up to 12 v level when a cell has failed and can produce only --- say 9v. the inverter would be pouring in charge in a futile attempt to get it up to 12V.
Not sure how the inverter operates if for example, only 30A (1 leg of 220 =110V is available). Does it feed both inverter legs, or does one half of Inverter not function? If not which of the 2 House legs doesn't get fed. Likewise, does the inverter not keep the Chassis batt's charged up?

[Bronccat]

I received several responses from Magnum that somewhat cleared the air but mostly confused me further. I'll post these when I am back at my computer.

Thanks

[twinboat]

Originally Posted by lbw6303

Seems to me that the Inverter should run even if no house batt's present -- if there is a load somewhere in the coach. It normally takes AC voltage and "inverts" it to DC to run lights, etc and/or to charge house Batt's. it should provide some output if, for example, the lights are turned on. Those lights should get sourced from the inverter. On the other hand, if no house batt's, the 10.3v makes no sense, unless that's a standby output w/ no load on the inverter. If house batt's installed, inverter on standby it seems like the 10.3 volts would be indicating a failed batt/batt's. That could explain "boiling over". The charger is trying to literally DRAG a failed battery up to 12 v level when a cell has failed and can produce only --- say 9v. the inverter would be pouring in charge in a futile attempt to get it up to 12V.
Not sure how the inverter operates if for example, only 30A (1 leg of 220 =110V is available). Does it feed both inverter legs, or does one half of Inverter not function? If not which of the 2 House legs doesn't get fed. Likewise, does the inverter not keep the Chassis batt's charged up?

Your explanation is all over the place and confusing.

An*inverter is an electronic device that changes*DC to*AC.

A converter/charger is a device that converts AC to DC.

I have not seen 2 legs of power hooked to an inverter in a MH. Most only feed 1 leg @ 120 volts.

To produce more then 30 amps AC, the inverter would have to be over 3600 watts.

I'm sure they make 240 volt inverters but not in MHs.

[lbw6303]

Sorry about that -- got my inverters/converters mixed up. I think of the Inverter box as also containing the "Converter" that functions as the Charger for the batteries and provides DC for 12 v stuff. The two functions are probably in the same compartment, but may very well be in two separate "boxes".

I'll try to edit my post here:
Seems to me that the Inverter & Converter should run even if no house batt's present -- if there is a load somewhere in the coach. The Converter should provide some DC output if, for example, the lights are turned on. Those lights should get sourced from the Converter rather than the battery.

On the other hand, if no house batt's installed, the 10.3v makes no sense, unless that's a standby output when no load on the converter. If house batt's installed, it seems like the 10.3 volts would be indicating a failed batt/batt's. That could explain "boiling over". The charger is trying to literally DRAG a failed battery up to 12 v level when a cell has failed and can produce only --- say 9v when not propped up by the charger. the converter would be pouring in charge in a futile attempt to get it up to 12V to stay.
Not sure how the inverter/converter(Charger) system operates if for example, only 30A (1 leg of 220 =110V is available). The reason I mention is that I'm plugged into 30 A plug in storage (rather than 50A -- two 110V legs/220V). Yet my (new) chassis batteries went dead. I'm trying to figure out how the two phase (220V) part of the AC input feeds the Converter/Charger. Does the Converter/Charger have two rails similar to the inverter and only one of those rails feeds the Chassis batt's to charge them and the other feeds the House batts?

I can pose that question on another thread rather than
hijack this one. Sorry.