Low Battery Voltage

[Mr__C]

2020 Keystone Cougar 26RBS. After a 4hr trip home, low voltage prevented the slide from opening. The fridge was running during the trip. Plugged in and opened the slide. The next day I had the battery tested and it's fine. I verified that the truck charges the battery. Yesterday, with battery at 13.6, I unplugged. Fridge was running. This AM, 6.3 volts.

What direction do I need to head? Only the fridge and propane detector were running on the battery.

[Mr__C]

valhalla360 wrote:

Mr. C wrote:

valhalla360 wrote:

Mr. C wrote:
OK. Regardless of all of this, I'll be getting a new battery. Went to Harbor Freight and got a cheap load tester and a CenTech 30a Circuit Tester #67724. Also cheap. It replaces the fuse and reads the amperage. I could get the battery to read bad if I kept the load on for 10sec. Interstate RV/Deep Cycle. 405CCA, 505MCA.

Fridge circuit .8-1.3
Propane detector circuit .2
The TV antenna is on one of the circuits and can't be turned off like in our last camper.

Converter voltage 13.6

Voltage at the truck plug 12.6

So, is the AGM battery worth the extra $100 compared to a flooded battery?

When parked at home, the camper is always plugged in. Good or bad? Or should I just use a battery tender?

Thanks for the input and help...

The AGM offers nothing in your situation (one battery-rarely off grid). More importantly, until you are sure there isn't a systemic problem, no chance burning up a more expensive battery.

Can I assume that the amp readings on those 2 circuits are normal? All other circuits were 0...

Yeah, that sounds fairly normal. What was the amperage direct off the battery terminal (this should include everything)? If it's 1-2amps, there's no major hidden draw.

Overnight (say 14hrs), that should be 14-28amp-hrs, which shouldn't kill a fully charged battery in good condition. (It might be down to 60-70% by morning but certainly not 6v which is beyond dead).

1.1-1.2amps at the new battery, measured with my new DCa clamp-on meter. Also have a new battery tester and a new 12v circuit tester. All good things to have, and it took a simple problem for me to get them. I'm glad it was just the battery all along.

[valhalla360]

Mr. C wrote:

valhalla360 wrote:

Mr. C wrote:
OK. Regardless of all of this, I'll be getting a new battery. Went to Harbor Freight and got a cheap load tester and a CenTech 30a Circuit Tester #67724. Also cheap. It replaces the fuse and reads the amperage. I could get the battery to read bad if I kept the load on for 10sec. Interstate RV/Deep Cycle. 405CCA, 505MCA.

Fridge circuit .8-1.3
Propane detector circuit .2
The TV antenna is on one of the circuits and can't be turned off like in our last camper.

Converter voltage 13.6

Voltage at the truck plug 12.6

So, is the AGM battery worth the extra $100 compared to a flooded battery?

When parked at home, the camper is always plugged in. Good or bad? Or should I just use a battery tender?

Thanks for the input and help...

The AGM offers nothing in your situation (one battery-rarely off grid). More importantly, until you are sure there isn't a systemic problem, no chance burning up a more expensive battery.

Can I assume that the amp readings on those 2 circuits are normal? All other circuits were 0...

Yeah, that sounds fairly normal. What was the amperage direct off the battery terminal (this should include everything)? If it's 1-2amps, there's no major hidden draw.

Overnight (say 14hrs), that should be 14-28amp-hrs, which shouldn't kill a fully charged battery in good condition. (It might be down to 60-70% by morning but certainly not 6v which is beyond dead).

[opnspaces]

I know you said you are buying a new battery but wanted to add my 2 cents. I once had a battery that would pass the tests and in the morning was dead. I asked the parts guy to charge it up and test it and then let it sit all night and test in the morning. It passed the test that night and failed the test in the morning. This sounds exactly like what you are reporting on your battery.

If you are mostly or always plugged in when camping then get a cheap 12 volt lead acid battery and go on with life.

If you dry camp often and have the room then put in two 6 volt batteries from Costco or Sams Club.

[pianotuna]

Mr. C wrote:


When parked at home, the camper is always plugged in. Good or bad? Or should I just use a battery tender?

Wasteful. Get a timer and power the RV for one hour a day. That will maintain the battery.

Many batteries die from over charging.

Keep looking for ways to eliminate the parasitic loads.

[enblethen]

Were you able to get a reading on the antenna circuit? It should have a fuse somewhere. You should be able to shut it off. Make and model of antenna?

[Mr__C]

valhalla360 wrote:

Mr. C wrote:
OK. Regardless of all of this, I'll be getting a new battery. Went to Harbor Freight and got a cheap load tester and a CenTech 30a Circuit Tester #67724. Also cheap. It replaces the fuse and reads the amperage. I could get the battery to read bad if I kept the load on for 10sec. Interstate RV/Deep Cycle. 405CCA, 505MCA.

Fridge circuit .8-1.3
Propane detector circuit .2
The TV antenna is on one of the circuits and can't be turned off like in our last camper.

Converter voltage 13.6

Voltage at the truck plug 12.6

So, is the AGM battery worth the extra $100 compared to a flooded battery?

When parked at home, the camper is always plugged in. Good or bad? Or should I just use a battery tender?

Thanks for the input and help...

The AGM offers nothing in your situation (one battery-rarely off grid). More importantly, until you are sure there isn't a systemic problem, no chance burning up a more expensive battery.

Can I assume that the amp readings on those 2 circuits are normal? All other circuits were 0...

[valhalla360]

Mr. C wrote:
OK. Regardless of all of this, I'll be getting a new battery. Went to Harbor Freight and got a cheap load tester and a CenTech 30a Circuit Tester #67724. Also cheap. It replaces the fuse and reads the amperage. I could get the battery to read bad if I kept the load on for 10sec. Interstate RV/Deep Cycle. 405CCA, 505MCA.

Fridge circuit .8-1.3
Propane detector circuit .2
The TV antenna is on one of the circuits and can't be turned off like in our last camper.

Converter voltage 13.6

Voltage at the truck plug 12.6

So, is the AGM battery worth the extra $100 compared to a flooded battery?

When parked at home, the camper is always plugged in. Good or bad? Or should I just use a battery tender?

Thanks for the input and help...

The AGM offers nothing in your situation (one battery-rarely off grid). More importantly, until you are sure there isn't a systemic problem, no chance burning up a more expensive battery.

[MFL]

It is good to keep it plugged in at home. Some converters may have an excessive charge system, that will cook the water out. Even then, if you check water level regularly, it should be okay. You can disconnect the battery if you want.

I have a PD converter/charger, that goes to float charge of 13.2, when battery is fully charged. I have not needed to add any water, but do check on occasion, and mine is plugged in from early Spring, till late Fall.

Jerry

[Mr__C]

OK. Regardless of all of this, I'll be getting a new battery. Went to Harbor Freight and got a cheap load tester and a CenTech 30a Circuit Tester #67724. Also cheap. It replaces the fuse and reads the amperage. I could get the battery to read bad if I kept the load on for 10sec. Interstate RV/Deep Cycle. 405CCA, 505MCA.

Fridge circuit .8-1.3
Propane detector circuit .2
The TV antenna is on one of the circuits and can't be turned off like in our last camper.

Converter voltage 13.6

Voltage at the truck plug 12.6

So, is the AGM battery worth the extra $100 compared to a flooded battery?

When parked at home, the camper is always plugged in. Good or bad? Or should I just use a battery tender?

Thanks for the input and help...

[time2roll]

I would start with charging the battery 72+ hours with the converter. Once charged, disconnect the cables and wait another 48 hours with nothing connected. While disconnected and resting a couple days the battery should hold 12.6+ volts.

Post the results.

[enblethen]

Mr. C, do you have an electric tongue jack? Some of the switches fail as they are in the weather. Check that to insure it is not using power when not in operation.
Another item to check is the breakaway switch for the same basic reason.

[Flapper]

CCA is not a very valid test for our use of a battery. That is a rating for how big a burst of power a battery can put out in a very short time (like for turning over an engine). Slightly more meaningful, but not much, is how many times the battery can pass the test without recharging. I've seen many that can pass the test once, but have no lifespan at all for longer term lower draws. Other than putting a know load on it, and periodically monitoring the voltage over time, there isn't any quick way to test for it's ability to deliver rated amp hour capacity.
If you have the meter, and time, you may want to swap with a vehicle battery and see how that does over time. But periodically monitor, so you don't over discharge your test battery and ruin that too....

[theoldwizard1]

pianotuna wrote:

theoldwizard1 wrote:
If you want to run the refrigerator on electric while driving, get a DC-DC batter charger.

As most fridges need 325 watts, a 40 amp dc to DC unit would work--but that requires a larger alternator.

Any truck with a trailer tow package will likely have an alternator capable of 200+A. Plenty to spare !

[Mr__C]

enblethen wrote:
You need to verify voltage from TV and battery to the 12 volt DC distribution panel.
Is your refer a three way or a two way? If three way it should be set to LP.

I will do this tomorrow. The fridge is 2 way and is running on LP...