One charger not working

[jelmore]

It appears one charger isn't charging. Our Liberty has two 2500 watt Freedom inverter/chargers. I don't know how they share the charging loads. We've been dry camping a lot lately and I noticed charger #1 would indicate an overheat, would reset, and then start charging again. Charger #2 doesn't seem to be doing anything. The dc amp load on charger #1 would be up at 130 and #2 would be at 0-10 amps.

3 or 4 months ago I changed the dip switch settings to the Liberty default which is all off. That setting disables "power sharing" and, I guess, lets the charger charge at full rate. The chargers are rated at 130 amps. To solve this until it gets fixed, I changed the power sharing setting to 20 amps on charger #1 and it is working, I guess, ok and is charging the batteries without overheating, though slowly. The dc load on #1 is around 70 amps and the batteries are slowly increasing voltage over many hours, something like 11 volts to 14 volts in 6 hours. Doesn't sound quite right to me. The charger breaker on #2 isn't tripped.

We're close to Liberty in Chicago and I am thinking they might be best to figure this out.

Or, would this maybe just for sure be a bad charging board? Maybe it needs further diagnosis?

Perhaps a call to Gusdorf might be in order before visiting Liberty?

What do you think? I know some here have repaired their inverters or had similar situations.

Does any of this sound familiar?

A basic question: how do the two chargers share the charging load? Do they talk to each other? If they are set to allow full current through, 130 amps, does each only deliver 65 amps? Surely they wouldn't deliver 130 amps each! I've never seen it so I don't think that happens.

Need some more school.

[truk4u]

Jim,

You have a lot going on, but check the internal inverter fan(s) and make sure they're running on the one that overheated.

[garyde]

Hi Jim. I would call Troy at Liberty. My understanding is limited, but I was told the inverters were working together, one being a back up to the other. When mine charge they charge at about the same load rate which indicates to me both are running & sharing the output charge. If you turn one off the other one will pick up the charging load. The 4 batteries I have are in parralell / Series so they are all connected to both Invertor/chargers.

[jelmore]

Gary, we're in Chicago so I'll check with Tony or Bill up here. Good to know yours charge at the same rate. Tom, the fans seem to be working. When I said 130 amps, that was total. Other dc loads were probably 30, so the charger was actually putting out maybe 100 amps. The second charger is for sure not charging.

[Joe Cannarozzi]

Jim when I needed repair Mr. Gusdorf diagnosed the problem on the phone.

He then inquired if I were capable and inclined to remove the "board" to reduce shipping and then proceeded to tell me every screw it the exact correct order of removal.

It was not hard. If I were inclined to have someone do that for me I would expect, maybe, take 2 hr out 2 in.

It will be interesting to see if you find another source for your part and repair after a conversation with the boys in N. Chicago in the morn. Take pictures.

[Jon Wehrenberg]

One thing everyone should know about our inverters is when charging either by being connected to shore power or receiving power from the generator they both have the ability to supply charging current to the batteries at the same time. They may charge equally as Gary has indicated, or one may handle the load. If there is ever any question about whether both are working because one always seems to carry the charging load, turn it off and see if the other one starts to pick up the charging load. You should be able to see on the remote panel when the inverters are charging, but if you want to verify it, hook your voltmeter to the house batteries and check the voltage with one or the other turned off. As long as the batteries are receiving a charge the voltage will be well in excess of 13 volts and possibly as high as 14.3 volts depending on where the inverter(s) are in the charging cycle.

A set of batteries not being charged will fall back to 12.7 volts or lower depending on their state of charge.

There is also a misconception that if a bus has two inverters the available power for 120V AC electric devices is their combined wattage and that they supply 120 V AC power together like they do on the 12 or 24 V DC output. Not true. Well, almost not true.

The inverter output when functioning as chargers can be combined and is combined.

The AC (alternating current) output on the 120V side is not combined. Each inverter either passes through shore or generator power to the circuits it is dedicated to power, or in the absence of generator or shore power converts battery power to supply 120 V AC power to the dedicated circuits and those circuits are isolated from one another. You cannot combine the outputs of two inverters to create one single circuit. The must always remain isolated. If your coach is set up with 2500 watt inverters for example, and one inverter has outlets, a refrigerator and an air conditioner on its circuits, the combined amperage or wattage for all circuits supplied by the inverter must not exceed the inverter rating. A 2500 watt inverter therefore can only supply 2500 watts of output power, or a little more than 20 amps total. Since a typical air conditioner will draw 13 amps when running there is not much additional capacity, and a refrigerator, or the TV's may exceed the output if added.

[jelmore]

Good description, Jon.

Some observations: when the charger is on, ac input to the circuits powered by that inverter seems to be passed through to those circuits. When the charger is off, the inverter seems to power those loads. On my charger #2 that does not seem to be charging, when I turn off the charger, the ac load displayed on my control panel drops approximately .3 amps. Turn the charger on and the ac load goes up the same amount when the ac input kicks in. Interestingly, there is enough of a delay (measured in milliseconds probably) in the switch from ac power to inverter power that sensitive items, like a powered usb hub or hard drive, will disconnect from the computer. Nothing else seems to notice, like a refrigerator or a lamp on an outlet.

The remote panel seems to be doing a fairly accurate job of measuring ac and dc loads, so if charger #2 doesn't show any charging load similar to charger #1, then I would assume that it isn't charging. I can't readily get to my house batteries so I can't verify that.

[Jon Wehrenberg]

As soon as an inverter that is supplying 120V AC power receives 120 V AC power the transfer is as fast as it takes a relay or some similar electric device to switch. You are right in saying it might be milliseconds.

There is a delay in charging however. I can't measure it, but when I turn the charging inverter off, the one that has been sitting idle picks up the charging responsibility, but there is a delay of a second or three.

If I am correct we also have delays in our transfer switch so as we go from power source to power source, or even device to device there are gaps.

You do not need to get at your batteries. Go to the electric bay and hook your voltmeter to one of the buss bars and a ground to measure battery voltage. Better yet, look at the house voltmeter on the dash.

[jelmore]

The dash house voltmeter matches, approximately, the display at the control panel for inverter/charger #1. Right now for example, both read 13v and a dc load of about 70 amps (+70 on the dash voltmeter). All of that dc load is coming out of charger #1 and #2 is idle.

Another observation:

Yesterday, I tried turning off charger #1, and charger #2 did nothing. Left it that way all day. And this is curious. The generator was in autostart mode and running. When the batteries got down to 11v, the generator stopped. I was able to restart it after turning off autostart. Glad I was there to see it happen. After turning on charger #1, and the generator again in autostart mode, the batteries got to 14v after about 6 hours of 20amp charging and the generator stopped. Someone asked if the generator stopped after the batteries are charged and I guess this confirms that.

[Joe Cannarozzi]

Jim I just got off the phone with Mr. G he said to shut the good inverter down, give a hard rap with your knuckles on the front of the faulty inverter in the upper right hand corner and see if the charger starts.

He has seen many loose connections to the internal switch that would cause this and that is where it is.

He also said yours are still not obsolete parts are still available for them out there and many repair shops are in the habit of just replacing the board to the tune of 600 bucks and they are repairable for much less.