Battery life, fridge only

One Marine battery is weaker than a real Deep Cycle battery.
Get rid of a Marine battery next time, anyone, any reader who has one. Uselss.

Solar really is the key. You can do a very simple solar system where you deploy a panel outside in the sun and plug it in to camper, or put a permanent one on the roof and have it always able to charge.
For you it sounds like 100 watts is enough, but is so cheap, go for at least 200 watts of solar, then you need a charge controller (mttp or pwm) and then just wires.
Youre looking at about $200-250 on ebay for this, give or take.

Just to keep batt running a fridge you can use a plug-in 50 watt portable panel.
A portable is useful also to keep your vehicle topped off.

opnspaces wrote:
Yes.

But as usual the true answer is it depends. There are more phantom loads on the battery than just the refrigerator. But typically a good battery will last about two weeks before going completely dead. If the battery is older it might not make it quite that long. If your battery is in fairly good shape though it should make it for at least a week.

What is your plan for recharging the battery after the two days? Are you relying on the tow vehicle to recharge it? Or are you getting an electrical hookup once you get to your destination?

This is a good answer and others who answered too.

I will add a few things not yet mentioned to help the cause.

1. The gas detector in your camper is normally wired live all the time. That is one of the small loads being talked about that you cannot turn off.

2. If your camper has a roof TV antenna with a booster amplifier, and that amplifier is left turned on, it will draw power all the time. Most of these have a small button you can push to turn it on/off. Turn it off to make the battery last longer.

3. The radio in the camper, some have a backlight screen that sucks power, not a lot, but it is still power. Most times the only way to unhook this load, is take the fuse out of it on the back.

4. Here is a power sucker, not sure what model/brand fridge you have. Some of the Dometic's have what they call a "Climate control" feature. That is a heat strip that warms the freezer door gasket area to not freeze up on humid days. Some of these have a rocker switch up at the top door gasket area of the freezer door to turn it "off". Make sure that is off. On the RM2652 fridge at least, that heat strip can be live all the time even with the fridge main switch turned off if the climate control switch is left on.

Battery size, type, age, and what state of charge it was in when it started all plays into how many days.

Many of the older campers never had a battery disconnect switch at the battery. You had to unhook the battery cable to stop these parasitic loads from draining your battery in a week or two. Now a days, campers do have disconnect switches, just the owner needs to remember to turn it off when the camper is not used. The ideal thing, you have shore power close to the camper being stored. Plug in a battery minder with a desulfate mode and the battery stays maintained at 100% all the time and in good condition if you have a lead acid battery. If you do not have power near by, then the solar charger just for the battery takes care of it as the other poster stated.

Hope this helps

John

What kind of batteries(12v starting, marine or 6 v GC batteries) do you have and how many amp hrs? How new are the batteries? With good batteries the answer is yes even with just 12v starting batteries. With good GC batteries you can easily go a week before the self discharge with just the refer on. Depending on the length of your trip to your camping spot and you alternator and charging system you could recharge on the trip. How many amps are going back to your batteries while traveling? Will you be dry camping or staying at a FHU park?

rwynkoop wrote:

SailingOn wrote:

time2roll wrote:
I have been skipping this step the last few years. Just load the fridge with cold food same as you would a cooler. By the time anything would get too warm the fridge is cooling it back down.

But turning on the fridge announces it's only a few days until we can leave! Who could skip that?

I agree, I'm always excited to go turn the gas on and start the fridge.

Excited...that reminded me of my brother when we were kids
Trips had to be kept 'secret' from him otherwise he would get SO excited he would get SICK and that was not pretty

SailingOn wrote:

time2roll wrote:
I have been skipping this step the last few years. Just load the fridge with cold food same as you would a cooler. By the time anything would get too warm the fridge is cooling it back down.

But turning on the fridge announces it's only a few days until we can leave! Who could skip that?

I agree, I'm always excited to go turn the gas on and start the fridge.

time2roll wrote:
I have been skipping this step the last few years. Just load the fridge with cold food same as you would a cooler. By the time anything would get too warm the fridge is cooling it back down.

But turning on the fridge announces it's only a few days until we can leave! Who could skip that?

Assuming the battery is close to full charge and there is not too much extra parasitic load you will be fine for a few days.

I have been skipping this step the last few years. Just load the fridge with cold food same as you would a cooler. By the time anything would get too warm the fridge is cooling it back down.

For every 100 amp-hours of usable capacity 3 day of fridge.

Consider a solar system and your battery issue goes bye bye.

Depends on the capacity of your battery. The average absorption fridge will use between 15-20 AH per 24 hour period.
You should be OK for two days without depleting the battery too low.