12 Volt Battery Drain

[T Alan B]

We have a 2019 29RS and are looking at upgrading our house battery. We replaced it last year with a 100 AH Interstate AGM battery yet when we boondock overnight the battery looses 50% of its power within a few hours. I'm considering a Lithium replacement because I don't want to add the weight of 2 AGM batteries. But I'm not sure I am really addressing my problem. I know things are running in the RV that will always drain power but this seems to be happening too fast. The only available power when we are un-hooked are the 2 USB ports in the bedroom. Do I need a new battery or do I have another problem? Thank You...

[Jkwilson]

Is your refrigerator on? Lights? Furnace? Water pump? Those all draw from the 12V system.

How are you determining the power capacity loss? Via the internal battery electronics or the panel in the RV?

[T Alan B]

Thanks for the follow up. Nothing is currently on. The RV is in the driveway. I have a Bluetooth monitor hooked up directly on the battery. This afternoon I unplugged the RV to see how long it would take to drain the battery and it went to 50% in less than 2 hours. If I pull the battery disconnect the power drains very slowly. A % or 2 every other day. I can't figure out what is draining so much power. Any ideas would be appreciated...

[TedS]

You could pull fuses. The fuse holder led will light up on a circuit that was drawing power, a normally on circuit.

[Jkwilson]

Thanks for the follow up. Nothing is currently on. The RV is in the driveway. I have a Bluetooth monitor hooked up directly on the battery. This afternoon I unplugged the RV to see how long it would take to drain the battery and it went to 50% in less than 2 hours. If I pull the battery disconnect the power drains very slowly. A % or 2 every other day. I can't figure out what is draining so much power. Any ideas would be appreciated...

What kind of monitor? Unless it has a shunt and requires you to enter battery AH, it’s not good info.

[tgodrich]

On my rig, I installed a voltmeter in the cabin to read the battery voltage, and I put a push button momentary on switch to read the battery voltage.

If you read the threads on this, the battery disconnect does NOT disconnect everything. If you want a true disconnect, I would recommend installing a boat battery disconnect (or just disconnect one of the battery terminals). I did add another battery, and the switch I added (needs to be high current) is a 4 position switch - battery 1, battery 2, both batteries, and no batteries (disconnected). This is a true disconnect switch. I put mine on the positive battery side, but you can also put on the negative. This switch goes between the batteries and the RV. I used a Blue Sea Systems 4 position Battery Switch part # BLS-9002E

The RV fridge (unless residential) will draw 12 volts when on, even if running on propane. The radio draws a bit, the propane leak detector, rear camera (I added a switch to this too), as do several other items in the rig, even when everything is shut off. If you are drawing down a battery to 50% in 2 hours, something is definitely on or shorted. Pulling the fuses will help you narrow what is drawing the current.

[Lonestar]

Thanks for the follow up. Nothing is currently on. The RV is in the driveway. I have a Bluetooth monitor hooked up directly on the battery. This afternoon I unplugged the RV to see how long it would take to drain the battery and it went to 50% in less than 2 hours. If I pull the battery disconnect the power drains very slowly. A % or 2 every other day. I can't figure out what is draining so much power. Any ideas would be appreciated...

For chasing down what ever is drawing current, an inexpensive DC ampclamp will allow you to effectively determine exactly the amperage being drawn. Then, using the above suggestion, start pulling fuses or turning off items until you get a reasonable current draw.

[Jlawles2]

T Alan B and Lonestar I could not justify the expensive Fluke (would love to have one) but instead chose a Klein. I did go with a 600 amp (for automotive work on the DC Stuff) but a 400 amp should be sufficient for most people. Available at the local orange box store possibly or for those keyboard shoppers like myself (box store ends up costing me money) home deilvery.... https://www.amazon.com/Klein-Tools-C...34&s=hi&sr=1-1

[Country Campers]

What I have done recently is installed 2 Lion Energy UT-1300 batteries, a Victron BMV-712 battery monitor and a true battery disconnect. The monitor has helped me see what each 12 v item draws when turned on. The couple items that are always drawing are the propane detector and the radio , this should not draw down a battery. I did have problems with our previous deep cycle battery not holding charge very long , which I verified when removed after about 3 days sitting on the bench it was dead, I think it was a junk battery to begin with, dealer installed. The lithium batteries are a huge upgrade and will definitely help with our dry camping stays. There could be a chaffed wire somewhere in your unit, maybe even in the brake wiring , that may be drawing your battery down, with out a meter to see what it is drawing it is hard to tell what the issue may be.

Brian

[Lonestar]

T Alan B and Lonestar I could not justify the expensive Fluke (would love to have one) but instead chose a Klein. I did go with a 600 amp (for automotive work on the DC Stuff) but a 400 amp should be sufficient for most people. Available at the local orange box store possibly or for those keyboard shoppers like myself (box store ends up costing me money) home deilvery.... https://www.amazon.com/Klein-Tools-C...34&s=hi&sr=1-1

Wish I'd gone with the Klein like yours. I bought a cheaper one:

https://www.amazon.com/KAIWEETS-Mult...NsaWNrPXRydWU=

It's OK and what little I use it for will be fine, but I think the Klein will last forever. I have a Klein digital multi-meter and it has held up well. Of course the Fluke is the meter!

[JustBob]

On my 2019 21g momentum.. with the battery disconnect switch in the "on position" ,I am drawing 0.45 amps... with the switch turn to the "off position" I am drawing nothing. So it's not any items that should be powered Direct from the battery ,it is something going through the battery disconnect switch.. If I turn my main breaker off on the electrical panel of the RV, I am still drawing the same 0.45 amps does anybody know what's hooked up after/ beyond the disconnect switch THAT does not go through the main switch panel of the RV?


FYI I just recently purchased it used, privately not through a dealer. I did bring the RV to the parts and service location the previous owner had used to service the RV, again not a dealer.. I basically paid for an hour and a half labor for a tutorial session just so I could go forward with a confidence of using the components of the RV correctly. I was thoroughly UN-impressed, the only Tech mechanic employed there, while he was knowledgeable, seem to be more of a shoot from the hip-self-taught type, rather than any Technical Training, he wasn't even using the voltage meter correctly I had to show him that was hooked up incorrectly. With that said I'm wondering if he altered any of the electrical components.
Any thoughts would be appreciated

Any thoughts would be appreciated

[TedS]

Where are your measuring current? If just after the switch or just before the switch, you are measuring only current through the switch. There may be devices, carbon monoxide monitor, not wired through the switch. The main breaker is ac not dc so it will not interrupt a dc battery draw.

[ncitro]

JustBob


Welcome to the forum! It depends how your unit is wired but usually the disconnect switch only disconnects the fuse panel inside. All the devices connected on the tongue draw current even when the switch is off. If you're putting it into storage it's a good idea to wire in a true disconnect right off the battery or pull one of the battery cables off.

[Yoda]

We have a 2019 29RS and are looking at upgrading our house battery. We replaced it last year with a 100 AH Interstate AGM battery yet when we boondock overnight the battery looses 50% of its power within a few hours. I'm considering a Lithium replacement because I don't want to add the weight of 2 AGM batteries. But I'm not sure I am really addressing my problem. I know things are running in the RV that will always drain power but this seems to be happening too fast. The only available power when we are un-hooked are the 2 USB ports in the bedroom. Do I need a new battery or do I have another problem? Thank You...

On thing that draws power in the background with the disconnect switch on is the radio(even when off) and anything else with a display. Find what 12V circuit that is on and turn it off and see what happens.

[Jlawles2]

Measuring amperage at the switch as wired from GD will LIE. You need to measure the amperage on the battery negative wire as close to the battery as possible and ensure there is only 1 wire leading from the negative pole of the battery.

GD normally comes off the battery to a distribution panel or bar or self resetting relay, then to the disconnect then to the switched components. Somewhere between the Battery and the disconnect they will branch off to the "ALWAYS SUPPLIED" components like the front jack, the gas detectors, and a few other circuits.