Parasitic power draw

chunker · 10-24-2017, 04:42 AM

I need help with batteries and finding and eliminating a potential parasitic 12v draw. There any many coached out there with similar setups. Mid to late 2000 era, freightliner chassis, DP, Winnebago body, etc. I have 3 house 12v batteries, 2 chassis. House batteries are wet cell in good shape. I regularly check water, has Magnum smart inverter/charger and ESP in coach. Batteries individually load test strong.

We have some new property along a FL Bayou near Freeport FL. We've cleared the land but no utilities yet so it's dry camping. Last trip was cool so we didn't need the generator for air conditioner but did run periodically to charger the batteries.

Overnight the batteries go from 12.7 to 12.0 - 11.9. In my opinion way too low for that time period. I have the inverter turned off so the refer is propane, we don't turn lights on unless necessary. I swiped out most interior and compartment with LED bulbs. I need a CPAP so have a small 400W inverter just for that and only turn it on to when using. Known parasitic draw. Refer uses some 12V, there are 2 radios part of the entertainment system, 1 in BR other in basement, that are off but illuminated in "standby". Possibly dash radio in standby will check dash position. Can't think of any other draws but I'm sure relays someplace use some. Pump is on but doesn't pump except for demand.

Anyone especialy someone with similar coach know of another course of parasitic draw or an item that's on that I'm missing? Seems to me I ought to be able to go longer than overnight without having to start the generator first thing in the morning to charge batteries. Course I have to start the generator to get the coffee pots going anyway.

Eventually, sooner than later I hope, we'll get the power and water to the site which will solve that immediate problem, but I sure would like to be able to boondock for longer periods without draining batteries.

staggerlee · 10-25-2017, 07:56 PM

Seems that everything that runs on elect. has some drow when off.
Your televisions foe example.
It keeps them warmed up for quicker starting when you turn them on.
Microwave with a clock. etc.

Balou · 10-31-2017, 12:54 PM

Turn off your water pump when not in use. It will draw power when switched on, but not being used.

luckydog08 · 11-08-2017, 06:05 PM

We recently replaced our Magnum converter charger with a gopower smart charger. Found that the Magnum did not charge with genset running. Also we replaced the 2 6v batts with 4 new Duracell batts. And installed a amp meter. Using amp meter we were able to locate every thing that uses 12 volts. For the TV and sat receiver we’ve plugged them into a power strip and when they are off they are OFF. I measured every single light bulb also. We bought a little suitcase charger rather than trying to park in the sun with roof top panels. No more power outages.

We turn the pump off at night because the drinking water spigot drips. Eventually that cycles the pump which is LOUD. I just stick an empty 12 oz water bottle under it and pour it in the dog’s bowl.

My understanding is that the temp compass display and dash radio run off chassis battery. As does the step light — you may not have one. The outside radio we disconnected. So far we’ve eliminated every amp leaker we can find and it seems to be working.

For the lighting I came up with a compromise solution. I replaced the three ceiling fluorescents with led tubes, ditto for my over the sink fixture. Every bulb in the compartments, shower, toilet room and so forth are LED but I left all the incandescent directional bulbs in. We only use them when we have shore power. I also left my vanity mirror bulbs for make up application.

chunker · 11-08-2017, 06:23 PM

We are heading down tomorrow for another 3 night dry camping. I have replaced all the incandescent bulb with LED and one of the fluorescent in the hall bath area. There are two large fluorescent fixtures in the living room that are not readily replaceable so haven't changed them yet. A big part of my problem was one of the house batteries was bad so I have removed it from the bank. Since it's a football weekend, we'll be running the gen a lot.

I'll turn the pump off because I can hear it cycle at night. The Dimension inverter is turned off so there shouldn't be any TV/DVD player/entertainment power draw. I can set the dash radio to either house or chassis battery. I'll make sure it's chassis this time. But I suspect I'll be better of just having removed the bad battery. After the first of the year I'm going to do serious research on 6V conversion.

wrayelwood · 11-09-2017, 11:45 AM

To find drain. disconnect all batteries at ground, start with motor batteries, then to Coach. Use a volt/ammeter or good 12v test light, connect between neg battery
& ground.. If light is on you have a draw- disconnect or remove fuse from each
until you find what is needing the power.
In my unit (03 Journey DL) i installed master disconnect switch for both sets.
Also installed a 'Buss bar' for each Motor & coach, then installed each main cable that was 'stacked' on the batteries to it. Now I do not have voltage drop...

Quote:

Originally Posted by drwwicks

I need help with batteries and finding and eliminating a potential parasitic 12v draw. There any many coached out there with similar setups. Mid to late 2000 era, freightliner chassis, DP, Winnebago body, etc. I have 3 house 12v batteries, 2 chassis. House batteries are wet cell in good shape. I regularly check water, has Magnum smart inverter/charger and ESP in coach. Batteries individually load test strong.

We have some new property along a FL Bayou near Freeport FL. We've cleared the land but no utilities yet so it's dry camping. Last trip was cool so we didn't need the generator for air conditioner but did run periodically to charger the batteries.

Overnight the batteries go from 12.7 to 12.0 - 11.9. In my opinion way too low for that time period. I have the inverter turned off so the refer is propane, we don't turn lights on unless necessary. I swiped out most interior and compartment with LED bulbs. I need a CPAP so have a small 400W inverter just for that and only turn it on to when using. Known parasitic draw. Refer uses some 12V, there are 2 radios part of the entertainment system, 1 in BR other in basement, that are off but illuminated in "standby". Possibly dash radio in standby will check dash position. Can't think of any other draws but I'm sure relays someplace use some. Pump is on but doesn't pump except for demand.

Anyone especialy someone with similar coach know of another course of parasitic draw or an item that's on that I'm missing? Seems to me I ought to be able to go longer than overnight without having to start the generator first thing in the morning to charge batteries. Course I have to start the generator to get the coffee pots going anyway.

Eventually, sooner than later I hope, we'll get the power and water to the site which will solve that immediate problem, but I sure would like to be able to boondock for longer periods without draining batteries.

puttin · 11-09-2017, 03:05 PM

As Wralewood explains you can see amp draw using his technique, or you can use a couple of other methods too. If you have a meter with an amp clamp it's just a matter of reading draw when the appliances are on- either totally or one at a time. It's also possible to check voltage drop at your panel by removing fuses (12v side) while watching voltage on your meter. To be as accurate as possible have the meter set to hundredths of a volt. Finally- here are some examples of typical draw of various CPAP's in different modes. You've probably already looked up some of this. It's also somewhat important to know that using these in DC mode is more efficient than off of an inverter.

https://www.cpap.com/cpap-faq/Power.html
http://www.healthyresources.com/slee...s/power03.html
https://www.guaranty.com/blog/what-s...-run-my-cpap-1

At 11.9 to 12V your batteries are basically dead. If this has happened many times it's very likely you've reached end of life for them and before you replace them you should get those loads under control and verify the converter/charger is doing it's job. A cheap single stage unit should charge at a rate of at least 13.5 to 13.7V.- You probably have at least a 3 stage unit in your rv which does better. The water pump uses no current unless it's actually pumping- so unless it cycling constantly, leave the switch on. Providing your incandescent lights are off as well as the tv- the biggest loads will be the fridge and the CPAP (with the inverter). I'm assuming that you're checking the batts in the morning while they are at rest (with no loads and sitting for at least an hour idle).

Jim_HiTek · 11-12-2017, 09:47 PM

If your refer needs to run during the night, and is it has a 12V heater, that will definitely draw your batts down. Best to set it for propane. Even then it's circuitry draws. Than you have the engine and tranni and radio memories.

What I'd do, is wire a temp 12V, pos and neg, to the refer, and then disconnect the main ground at the batteries every night. And have a few LED flashlights to get around at night. Or you can buy a set of the batt switches that attach directly to the batteries.

Once you've got the time and inclination, you can try to track down all the vampire loads.