Inverter use

[Toby]

I sholud know this stuff but have not really used an inverter for any length of time in all our camping trips. This weekend, we dry camped for the whole weekend and ran the gen in the morning and evening. I noticed the volts got down to 12.2v each morning. I have 4 wet 6 volts batts. After we got home I hooked to shore pwr 120v and the batts showed 13.4v when I disconnected the shore pwr., it was on float chg at the time.

Some qxs I have are how low can I let the batts get to before I need to use the gen pwr? At what volts do they receive perm harm? Is there an easy way to determine when I need to replace the batts, i.e., only charge to a certain voltage, discharge real fast and etc ? What else should I look out for? Tnx s/Toby

[RV Wizard]

Toby, I would not let the battery bank go below 12.0 volts before recharging. Anything below 50% discharge over time does not help battery life. You will want to make sure the batteries are always maintained by keeping the plates covered with distilled water, the terminals are kept clean and I would recommend desulfating the batteries with an equalization charge once in a while. Good luck and keep us posted.

[Mike Canter]

This chart may help. This is without the generator on and everything 12 volts turned off.

Open Circuit Voltage (12 V)


Approximate charge

12.65 V
100%
12.45 V
75%
12.24 V
50%
12.06 V
25%
11.89 V
0%

[Toby]

Tnxs Mikes

Good info. How do I desulfunate the batts? Can I do it with my inverter? s/Toby

[Dennis Wells]

You didn't ask, but when drycamping on most coaches turn the inverter off when it is not needed.

[DAN L]

Quote:

Originally Posted by Toby Tnxs Mikes Good info. How do I desulfunate the batts? Can I do it with my inverter? s/Toby

to "desulfate" or "equalize" charge batteries you need a special charger. the charger must be capable of at least 15.5v output. my onboard converter bulk charges at 14.1v, about the same as the engine alternator. after the bulk charge, my converter switches to a 13.5v float charge.
i bought a schumacher charger designed for this purpose from schucks auto supply. in the desulfation mode, it pulses the voltage so it does not generate too much heat and gasses less. the voltage runs 16v+ intermittently. the charger i have also charges small motorcycle batteries.
when i had 2 12v deka batteries hooked up in parallel, it was necessary to separate them (disconnect the ground cable) and charge them individually to desulfate them. the cycle took 4-6 hours on each battery. the batteries had to be over 50% discharged before the schumacher would go into the automatic desulfate or equalize cycle.
i have not had to desulfate my 2 lifeline 6v batteries hooked up in series yet.

[RV Wizard]

Quote:

Originally Posted by Toby Tnxs Mikes Good info. How do I desulfunate the batts? Can I do it with my inverter? s/Toby

Toby, what inverter do you have? Some inverter chargers with three stage charging can indeed do equalizing of the battery bank.

[Toby]

Mike

I have the Magnum ME 2012 Inverter with the energy mgt system on the inside. The highesr I've seen it charging was 14.3volts. Is there a setting to get it to equalize? I guess I need to get a charger that will equalize. Turning off the inverter is a good idea. I'll do that when not in use. Thanks folks s/Toby

[SacsTC]

Quote:

I have the Magnum ME 2012 Inverter with the energy mgt system on the inside. The highesr I've seen it charging was 14.3volts. Is there a setting to get it to equalize?

Toby,
Yes it will do equalization. At the bottom of page 27 of this manual are the instructions.
Equalize will not start unless charger is in float or full battery mode.

[Toby]

SasTC

Thanks. I found the manual okay and see how you equalize the batts. I do not have this manual. Guess someone took it out of the MH before I purchased it. This is what I needed all along. s/Toby

[RV Wizard]

Toby, glad you have found the manual to instruct you on how to use the equalize mode on the inverter/charger. Might I suggest that when you do this, that your disconnect the loads downstream. Some control boards may not like the high voltage that this mode will be using. If your disconnect is wired to where the inverter is still connected to battery bank but the distribution panel is not, use it. If it is wired that the disconnect is between the battery bank and the inverter you can pull the fuses in the distribution panel and leave the disconnect on. When I equalized my bank, this was the time I would defrost the refrigerator. The equalizing usually is an 8 hour deal.

[Toby]

Mike

Tnx for this good info, I think. Now I have to use my gray matter which is very thin these days to figure out the electrical connections. I think I'll wait until we get back from our trip to the Natchez Trace to try to equalize my batts. s/Toby

[Rick Long]

The numbers are from Trojan Battery Co., the shading from several different charts.
I made this in MS Works Spreadsheet and here is a link to the file: http://www.really4me.com/pictures/Ba...argeStatus.xlr

SAVE the file... Do NOT OPEN from the web site or it will try to open Works too.

It's all set to print only the chart... Just click on the PRINT icon. I suggest photo paper for best results. I laminated mine and stuck it in my battery bay so I can see it when I check the batteries.

[RV Wizard]

Quote:

Originally Posted by Toby Mike Tnx for this good info, I think. Now I have to use my gray matter which is very thin these days to figure out the electrical connections. I think I'll wait until we get back from our trip to the Natchez Trace to try to equalize my batts. s/Toby

Toby, it is not hard to figure out. While plugged into power; put a volt meter on the battery bank. Disconnect battery with disconnect switch. If the battery voltage does not drop and the lights, refrigerator and appliance controls are inoperable, all you will have to do is use the battery disconnect when you go to equalize. If the battery voltage does drop off, this means that the disconnect is between the inverter and battery bank and you will have to manually disconnect each vulnerable circuit.