Foretravel Owners' Forum For owners and Fans of Foretravel Motorcoaches September 12, 2025 ...

Amp Draw

September 22, 2015, 10:11:49 am

I was wondering if you could tell me what would be a acceptable level of Amp Draw on my system when dry camping ?
There seem to be a lot of different information on this subject , I realize the less the better, however you can't turn everything of.
I look forwards to your answer .

And how to find the culprit that causes my concern.

Thank you
Rob.

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Re: Amp Draw

Reply #1 – September 22, 2015, 10:29:32 am

Not much draw if you change out your bulbs for LEDs and replace the CRT TV with a LED (not plasma!). We also shut off the inverter (OEM and still working well) when we go to sleep. I hate the sound of the bedroom heater so leave it off and just use the front one. We also have a unvented heater (modern sales term is "vent free") that uses no juice. Microwave takes much longer with the inverter but is OK.

If you don't have a solar setup like ours, you would want to run the generator in the morning. The house batteries like a shallow discharge for maximum life. Increasing the battery capacity (more batteries) lowers the percentage of discharge each day cycle.

You didn't say anything about your symptoms. What problem are you having?

Solar is pretty inexpensive if you DIY. Will extend the life of the batteries.

Pierce

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Re: Amp Draw

Reply #2 – September 22, 2015, 10:57:12 am

We're all different. Some of us have CPAP units going all night long, there are people who can't sleep without the TV going in the background and/or a light on somewhere, etc. You don't mention whether you already know how much current is being drawn from your system but, as far as I'm concerned, that's the first step.

A lot has changed in the battery monitor world. A few years ago there was only the Bogart Engineering Tri-Metric 2025 but now there's more choice. Bogart has a newer version, Midnite Solar has a product that works in conjunction with its solar charge controllers (which quite a few of us are using), and more. Just Google "rv battery monitor" and see what's out there.

One thing they have in common is that in order to measure current flowing out from a battery you have to either have a meter in series with the entire flow (usually in the ground lead) or you have to use a "shunt"; as far as I know, they all use a shunt. A shunt is a very low value resistor placed in series with (usually) the ground connection of the battery bank you want to measure (usually the house bank). This low value resistor does not drop voltage significantly but just enough so that the current draw can be calculated by measuring that tiny voltage (using Ohm's Law).

The TriMetric 2025 does much more than simply measure current flow (amps); it gives you a method of managing it. Here is a video that briefly demonstrates the 2025. It doesn't explain how to configure it but there are other videos on YouTube that will do that for you. http://www.youtube.com/watch?v=9pk3ycLK7_c

(Here I should explain that the TriMetric can only be set up for one main bank; usually the "house" bank. It will measure and display the voltage for the engine (chassis) bank but won't give you detailed information on that second bank.)

So the first step would be to see what the draw is when you think everything is off. Then, by shutting down breakers one-by-one you have at least a chance of finding the rest (refrigerator, inverter, TV sets that you think are turned off but really aren't, etc.).

An acceptable level of overnight current draw for me is one that allows my solar panels (700 watts more-or-less) to recharge my house batteries by about noon. This gives me the rest of the afternoon to recharge anything else (trolling motor battery, laptops, cell phones, neighbors, etc.) That "after noon" power is free as far as I'm concerned so that's when you can use your shop tools and the like.

You can never get rid of that "parasitic" current draw overnight (unless you simply disconnect your battery bank) and the newest coaches are probably worse than the older ones. But you can identify most of them and deal with them. Or install enough solar to handle that draw.

Craig

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Re: Amp Draw

Reply #3 – September 22, 2015, 11:27:38 am

If no compressor side of my refer is used and the chest refer is on and normal Aqua hot diesel usage in down to 40 degree at night weather and with led lights and light inverter use we run around 160 amp hours overnight.

Big percentage is the compressor motor in the chest freezer.  Aqua hots motors and pumps are next in draw.

Hardly turn on our led tv's or satellite but they do draw a fair amount.

Original freedom 25 inverter.

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