Easy & Cheap way to determine battery draw
I would like to do some boondocking in Oct. How can I determine battery drain when I turn on a device, like a TV, amp, etc... while boondocking? Looking for an easy/cheap method to accomplish. Thanks
Forum Discussion
Hi,
I have a E-Meter, it is about $450, so probably way out of your budget for something to buy for the RV. Even I did not want to buy it, would have rather bought a 75 watt solar panel at the time, it would add energy, not measure it.
Anyway the E-meter tells me a lot. It carefully measures the amp hours going into and out of the battery bank. How does this help you? Well I can tell you that the refrigerator, CO meter an propane leak detectors use a total of about 35 amp hours per day, about what one of my 120 watt solar panels will put out in a day. Each light bulb is about 1.1 amps, while I changed to 24 LED panels, that are only 0.1 amps each, and two of the panels are brighter than one of the old light bulbs. I put in 4 of the LED panels in the porch light, it is really bright now, and only 0.4 amps, about 1/3 of the old light.
Your furnace is another large load. It can draw 5 - 8 amps per hour, though you only normally run it about 2 hours per day, unless it is really cold out. I have a Olympic Catalytic heater, no 12 volt power at all, but I need to leave a roof vent and window open all the time (just like while cooking).
Your charger should be putting out about 35 amps per hour to a pair of batteries, in the first hour. The second hour is going to be less, say 25 - 30 AH, depending on how full the battery is getting. 3 and 4th hours, probably less than 20 AH per hour,and it will taper to even less power per hour after that. It is better to run the generator for about 1 hour early morning and later in the day, it gives the most amps per hour that way
Fred.
I have a E-Meter, it is about $450, so probably way out of your budget for something to buy for the RV. Even I did not want to buy it, would have rather bought a 75 watt solar panel at the time, it would add energy, not measure it.
Anyway the E-meter tells me a lot. It carefully measures the amp hours going into and out of the battery bank. How does this help you? Well I can tell you that the refrigerator, CO meter an propane leak detectors use a total of about 35 amp hours per day, about what one of my 120 watt solar panels will put out in a day. Each light bulb is about 1.1 amps, while I changed to 24 LED panels, that are only 0.1 amps each, and two of the panels are brighter than one of the old light bulbs. I put in 4 of the LED panels in the porch light, it is really bright now, and only 0.4 amps, about 1/3 of the old light.
Your furnace is another large load. It can draw 5 - 8 amps per hour, though you only normally run it about 2 hours per day, unless it is really cold out. I have a Olympic Catalytic heater, no 12 volt power at all, but I need to leave a roof vent and window open all the time (just like while cooking).
Your charger should be putting out about 35 amps per hour to a pair of batteries, in the first hour. The second hour is going to be less, say 25 - 30 AH, depending on how full the battery is getting. 3 and 4th hours, probably less than 20 AH per hour,and it will taper to even less power per hour after that. It is better to run the generator for about 1 hour early morning and later in the day, it gives the most amps per hour that way
Fred.
