AC power problem

[Jeff Watt]

Thanks Gerald,

We had to go out for awhile so I turned the genset off. At the time it showed absorption charge and 76% SOC.

Almost immediately after turning the genset off, the xantrex meter showed increasing SOC; watched for a couple of seconds and it was 80 when we left. On return it is 100%.

Could this have anything to do with new batteries and very few (2 or 3) discharge and recharge cycles from a low soc starting point?

Thanks again for the insight about equalizing.

Jeff

[Edward Buker]

Jeff,

The Xantrex is not perfect in its conveying of the charge status results. It basically has a battery bank accepting current and it steps through a charge routine supplying current at various logical voltages to maximize the capacity of the bank. I'm not sure if the Xantrex was telling you 76% of being finished with absorbtion or 76% SOC. The fact that you were in absorbtion means that you were in a finishing state for the charging and basically were close to going to a float state which is a mantenance state for charging.

After the generator was shut down it will take 20 minutes or so for the batteries to drop the voltage levels that the charger was putting on them and settle at the final voltage and charge state. 12.6 to !2.7 volts represents a fully charged battery with light or no load on it. The most accurate charge state measurement will be taken at this point with the Xantrex not charging and just battery voltage measurements providing the results. You need not worry, it would appear that your batteries and charging system are acting normally. If you reach absorbtion consider your batteries at a high state of charge and ready for use.

Regarding your Surge Guard issue. You could take the input side from the cord and couple it with large wire nuts to the output wiring side of the surge guard that feeds the coach. Tape over the wirenuts after they have been tightened.  You would leave the generator wires connected in the Surge Guard and the generator would be unable to connect to the coach. That would enable plugging in and not running the generator if you are staying each night in a campground with a power source. If you had the need and were forced to use the generator you would reconnect things as they were. This is just another choice if it suited your situation better. The neutral, ground, and hot leads woudl need to be connected properly to the coach wiring. Usually that is straight forward by the wiring position on both sides of the relay and wire color code but I have not been inside a Surge Guard to be sure.

Later Ed

[Gerald Farris]

Jeff,
I think that the erroneous SOC (state of charge) readings that you are getting are based on the technical inability of the Xantrex unit to give you any more accuracy than it does.

If you want an accurate SOC reading for your batteries, you need to install a battery monitor that is designed for the purpose. A battery monitoring system uses a method to determine the amount of discharge and recharge in amp/hours for a battery bank, usually by use of a shunt. Therefore the battery monitoring system can determine exactly how many amp/hours are left in the batteries for use, also known SOC (state of charge). Your inverter does not have this ability and therefore the SOC readings that you are receiving are just approximations that are inherently inaccurate now just like they were last year.

Gerald

[Jeff Watt]

Gerald, Ed

Thanks for the information; your experience helps greatly.

The Aladdin is showing 12.4v and the xantrex is showing about the same, with a SOC of 91 (we used the inverter for a few things last night and being 50F outside, the aqua hot was/is on). I'll probably fire the genset up sometime today but thanks to your insight I won't fret about it as much.

Is it because the xantrex can't give a true reading that the soc dropped dramatically when I used the microwave even though the genset was running at the time? So are all the readings on the xantrex to be taken with some degree of caution/sceptism? As it provides soc, v, time left to charge, time left to run, avg shunt amps, input amps, etc.

Ed, your suggestion is similar to what SurgeGuard suggested I do to test the unit, but I think I feel more in control with a genset available than only shore power. We can llive for few days on battery and use the genset (either stationary or while driving) to replenish. Plus, at a park I can run an extension to use some high draw appliances.

Great to have this forum to discuss issues that I (and likely others) don't fully understand.

Thanks again.

Jeff

[Jeff Watt]

Still on the road and managing quite well with generator and batteries, although A/C would have been nice at a park last night at least for awhile.

I was speaking with another RVer the other day and on his American Eagle, he had a similar problem. Turned out it was not the surgeGuard unit but rather his inverter.

I don't know if this is the issue, but I do have a question regarding my inverter (which still produces AC from battery):

the reset button will not go in and stay in.

I am not sure if it is supposed to go in and stay in (looks like in the manual)? Can this be the problem? I don't understand how it could be but then I know very little about this.

One other thing, what might be a parasitic draw on the house batteries. When no lights are on, inverter not on, there still is a slight draw of maybe 1-3amps. So by morning the batteries are down 4-6%. I know temperature can cause some fluctuation. Does the fridge use some (not when the fans are running)?

Jeff

[Edward Buker]

Jeff,

The parasitic draw seems about right, not everything is truely off. If your inverter charges and inverts then it is fine and the reset button must be a momentary type switch. I'm not familar with what you have in the coach but the functioning is what matters. If the reset needed to stay in and was not then functionality would be affected. Your problem cannot be the inverter because circuits that pass through it still work as well as those AC circuits that are not on the inverter leg also function. Your problem is between the main power cord end and the main transfer switch. With generator on all AC circuits function normally and the generator passes through the transfer switch.

Later Ed