Parasitic Drain on 12V system

[Stan&Sharon]

Originally Posted by JimD

With a single battery starting at 12.34 volts I find it hard to believe you could get 8 hours while pulling 10.5 amps. I would expect far less time before you hit the recommended 12.1 volts shut off before battery damage.

I have 3 interstate group 24dc flooded batteries, each has est 64AH... haha.. sad but true. I've entered 180AH total available into the monitoring software. That's how it can guess around 8 hours remaining.

[ttavasc]

Originally Posted by Stan&Sharon

I have 3 interstate group 24dc flooded batteries, each has est 64AH... haha.. sad but true. I've entered 180AH total available into the monitoring software. That's how it can guess around 8 hours remaining.

If you have the Interstate HD24-DP FLA batteries they are 64ah each so I would enter 192 for the Battery Capacity in the VictronConnect app. I believe the "Discharge Floor" defaults to 50%, but if not, you can adjust it as needed. Given those parameters the ~8hr remaining estimate would be accurate assuming a full charge when the SmartShunt sync'ed to 100% SOC. Our ORV came with a pair of those Interstate HD24-DP batteries and the short time we used them before upgrading to a pair of Trojan T-125 6v GC2's I found that they didn't hold up that well under a heavier draw. I'm not surprised to see the voltage drop a bit under the 10amp load with those batteries.

[Eric H.]

FYI, I read one person say they would look for a short to account for a battery drain. A "short" means the circuit has shorted to ground and will either fry the fuse, wires, battery or wires and battery if there's no fuse in the circuit.

A stereo display won't drain your batteries overnight.

As far as dry camping, it amazes me the lengths people go to make up for a lack of amp hour capacity and how many people are still buying wet batteries for an RV that they plan on dry camping in.

[Vicr]

Has the OP had the batteries load tested??

[SAMM Kinder]

The furnace is a battery killer !! And a great battery is a must .... Put a test light between the unhooked bat terminal and the cable ... If it lights there is a draw ...... Have someone watch the test light while you pull and reinstall fuzes till the light goes out .. Thats the circut with the draw.... I do have a 1000 W generator I run for an hour durring dinner prep .. as I do run a CPAP (wired for 12 volts only) This system works great for me .. and I have a 4 year old battery .... O and unplug your TV or anything else with a off light durring testing

[teach]

How do you guys connect you cpap to power. We are heading RMNP next summer and I have been trying to figure out the cheapest way to power my cpap. We will be there 4 nights in July.

This will prolly be the only dry camping we do for years, so investing in an expensive system doesn’t make sense.
Thanks for your input.
Bob

[thenne1713]

Originally Posted by 907-Jayco

Hey all!

We are having trouble keeping our 12V house batteries juiced overnight when dry camping. On my last overnight, I parked after a 2 hour drive, checked them with a multimeter (13v.) Stayed outside the whole evening (no lights, no TV, no nothing) and went to bed at 11:30P using only my flashlight. The only appliances on were the Sony head unit (which I always dim, but I'm sure sucks a little juice regardless) my Norcool fridge running on propane, and the furnace. It was a chilly night, but I keep the furnace pretty low.

Even after all that, I woke up at 4AM and noticed the Norcool light was red. Every time that happens, I know there isn't enough juice to fire up the fridge.

Went and measured the house batteries...11.6!

Here is what I've tried so far:

- Checked all basement compartments for lights left on
- Pulled batteries and ran a cycle with a Noco Genius10 (Thanks to those who weighed in on my thread about trickle chargers).
- Checked water level in batteries
- Every day I check the batteries with Main Power off, and they hold at 12.66. So, my inexpert opinion says the batteries are probably fine?

The only thing I can think of to do now is go fuse-by-fuse to see if I have a short somewhere...but that's a long, arduous afternoon since I don't know what fuse is mapped to what device. Is there something simpler I'm not thinking of?

Could it be the Sony head unit they started putting in the 2021s? The screen seems like it has pixels lit up even when it's in "hide display" mode.

It is NOT Uncommon for FURNACE to draw down a single Group 24 or Group 27 battery in 5-6hrs and require you to Boost start the GEN; if you have a rig that also uses a LP solenoid on the tank, controlled by the LP/CO ALARM DETECTOR, Might be even faster? (From memory?) Group 27 only give 10-20% more than Group 24?

[Mikec557]

Originally Posted by teach

How do you guys connect you cpap to power. We are heading RMNP next summer and I have been trying to figure out the cheapest way to power my cpap. We will be there 4 nights in July.

This will prolly be the only dry camping we do for years, so investing in an expensive system doesn’t make sense.
Thanks for your input.
Bob

It depends on which power source next to the bed. The lowest battery draw is to get a power supply that runs on 12vdc rather than 120vac. I bought a 12v power supply for my ResMed AirSense 10 on Amazon for $35. It has a cigarette plug on one end.

If you don't use a 12v power supply, then you'll need to buy a small $65ish true sine wave inverter to power your 120vac CPAP power supply.

For what it's worth, my ResMed actually operates on 24vdc. So regardless of 12vdc or 120vac power supplies, they're going to change the voltage to 24vdc.

The 12vdc power supply draws half the power from the rv/house battery compared to using the inverter. I recently tested mine. For

8h15m of sleep, it drew 6.538ah, or 86.5wh, from the rv/house battery. I DO KEEP the heated humidifier ON. I sleep better that way and it doesn't really draw that much more power from the battery. I have it set to 5. If I run it off of an inverter it draws about double the Ah/Wh.

If you can, and if it's not already there, install a cigarette lighter adapter within about 6ft (the length of the cord on the power supply) of the bedside table.

How many usable Amp hours do you have available at the start of bedtime?

Hope that helps.