Power leaks, how do you track them down?

nwcanopies · 10-03-2011, 08:31 AM

Fall is upon us and we are in a State Park her right outside of DC. We've been plugged in the last 2 months here and there so haven't experienced this, but last night and the night before the coach using ONLY the furnace sucked our batteries dry. Its only 45 at night and we keep our 300' at 65 so its not working that hard.

At 3am dead after a full charge, seems like we'd be getting more than one night out of the batteries, but I'm new to this game so school me please!

The batteries were both new in the spring, however i haven't checked the fluids in them. I'll do that first. We've been full time for 4 months.

dsbike · 10-03-2011, 08:45 AM

Were you plugged in last night? I am sorry I can't help you with this, I really don't know how much power the heater will actually draw if just using battery power. I am always plugged in or use the generator if not & know I am going to be draining power continuosly for a long period of time.

JimM68 · 10-03-2011, 11:33 AM

The blowers in the propane furnaces do suck a lot of juice. even set on 60, if it's 40 or less outside, they will bring your battery to its knees overnight.

bbeane · 10-03-2011, 06:00 PM

Quote:

Originally Posted by JimM68

The blowers in the propane furnaces do suck a lot of juice. even set on 60, if it's 40 or less outside, they will bring your battery to its knees overnight.

Ditto, also the colder the battery's get the less compacity they have. also if you are staying in the RV you are useing lights, fridge, water pump, Tv with small inverter, it adds up real quick.

nbounder · 10-03-2011, 08:49 PM

The title of your question asks about locating power leaks. There's an easy way and a hard way, depending on the severity of the task. When I need to do it, I start the easy way. have assistant reading the battery voltage. Remove all the 12V fuses. Now, plug in one fuse at a time, and have assistant record/report the voltage, then remove the fuse and plug in the next fuse. if you have any serious issue, the voltage will really dump when its fuse is inserted. The hard way is to insert an ammeter into the supply line right off the battery, then plug in one fuse at a time and measure/record the ampere draw. Either way, an offending circuit will usually jump out at you.

Dave78Chief · 10-04-2011, 11:56 AM

Measuring amperage does not have to be hard. Just run down to Sears and get one of these clamp-on DC Amp meters http://www.sears.com/craftsman-digit...p-03482369000P. Most clamp-on meters only do AC but this one is AC & DC and is the best price I have seen for one. They are also real nice for measuring battery loads for load estimation as well as charging current. Side benifit is that it also measures AC/DC voltage, Ohms, and includes the measurement bulb for temperature (handy for determining if the AC is really dropping the ambient temperature by 30 degrees).

Now the questions become:
Do you know how to compute daily amp-hour usage needs?
Do you know how to size your battery to satisfy those needs?
Do you know how to isolate the parasitic loads?

Dave

Midniteoyl · 10-04-2011, 12:34 PM

First, you need to know how many Amp Hours your batteries are rated at.. Then you need to see how much power you are drawing over night (furnace, lights, pumps, etc..). If the draw exceeds the Amp Hours, you need more battery capacity. If it is less, then you need to check that your batteries are fully charged to begin with. This is done with a hydrometer..

http://www.batterystuff.com/tutorial_battery.html#6

While there, check the condition of the battery terminals and connections. The batteries should be cleaned using a baking soda and water solution; a couple of table spoons to a pint of water. Cable connections need to be cleaned and tightened as battery problems are often caused by dirty and loose connections. A serviceable battery needs to have the fluid level checked. Use only mineral free water, Distilled is best as all impurities have been removed, and there is nothing left that could contaminate your cells. Don't overfill battery cells especially in warmer weather because the natural fluid expansion in hot weather can push excess electrolytes from the battery. To prevent corrosion of cables on top post batteries you can use a Battery Terminal Protectant spray (red), or use a small bead of silicone sealer at the base of the post and place a felt battery washer over it. Coat the washer with high temperature grease or petroleum jelly (Vaseline), then place cable on the post and tighten. Coat the exposed cable end with the grease.

Confirm these before chasing down a suspected parasitic power draw...

nwcanopies · 10-04-2011, 07:52 PM

Bunch of Very helpful stuff! I will do what is suggested! I will be adding 4-6 6v T-105's soon with the 400 watts of solar. I think that will help some. Bunch of learning for a newb.