Battery current draw |
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Colorado r-pod guy
Newbie Joined: 09 Oct 2015 Location: Colorado Online Status: Offline Posts: 14 |
Topic: Battery current draw Posted: 09 Sep 2018 at 7:58pm |
Greetings Helpful R-Podders, I am looking at ways to decrease power usage when on battery with my 2011 R-176. One thing I have noticed is that every time I connect the battery I get a fairly large spark from the wire/terminal. I've tried removing all the fuses before connecting the battery and still get a spark, so obviously there is a significant current drain on the battery, the question is, what is causing the drain and is there anything I can do to eliminate the it? Many thanks, Tim p.s. There is probably a post on this subject already, but I searched and couldn't find it, please forgive me for that.
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StephenH
podders Helping podders - pHp Joined: 29 Nov 2015 Location: Wake Forest, NC Online Status: Offline Posts: 6326 |
Posted: 09 Sep 2018 at 8:28pm |
There is a certain amount of surge when the battery is connected as there are things that draw power even if everything is turned off. Things like the LP/CO detector or the circuitry for the AC/furnace or the radio or the refrigerator circuitry, etc. Some of these cannot and should not be disconnected (LP/CO detector, for example). It is a safety factor. Rather than continuing to disconnect and connect the battery, consider installing a battery cut-off switch (see my mods for an example). It won't eliminate the power drains but will make it easier to disconnect and reconnect power when you are not using your R-Pod. For us, we keep ours plugged in when it is not used since we park it in our driveway.
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StephenH
Happy is the man that findeth wisdom,... ouR escaPOD mods Former RPod 179 Current Cherokee Grey Wolf 24 JS |
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Colorado r-pod guy
Newbie Joined: 09 Oct 2015 Location: Colorado Online Status: Offline Posts: 14 |
Posted: 09 Sep 2018 at 10:05pm |
Thanks for the response. I suppose my thinking is that an RV electrical system should operate much like a house: When the main breaker is in the off position, you aren't going to have power anywhere in the house, but obviously that is not the case with an RV. I do have a battery disconnect switch, just haven't installed it yet. I've been taking the battery inside the garage when the R-Pod is not in use for more than a week or so just so the battery isn't baking in the summer or freezing in the winter. I'd like to be able to run the furnace off the battery while boondocking, but given the current draw I have doubts as to just how long I could get away with that without drawing the battery down too low. Naturally I could use a generator or photovoltaic system to charge the battery but would like to avoid that because I'd rather not shell out the money for something that would only be of use a few days out of the year.
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furpod
Moderator Group - pHp Joined: 25 Jul 2011 Location: Central KY Online Status: Offline Posts: 6128 |
Posted: 10 Sep 2018 at 7:46am |
If you flip the main breaker, there is no 120v power to the camper. That's how the system works. The 120v and 12v systems are completely separate.
Since the Pod doesn't come with a battery disconnect, you don't have any way to fully cut the 12v circuit, until you add one. As far as boondocking a couple times a year, and wanting to get by without a large investment to accommodate you 12v needs, surely as a truck owner, you carry a good set of jumper cables, right? In case of an emergency where you need to pump a few gajjillion electrons into your Pod battery, turn your truck around, hook up jumper cabled to your Pod battery, start truck, idle for 20 minutes. It's hard to say how long you can stay out with a single group 24 battery before you need to top off the batteries, because only you know what all you are going to need/want to run. The wife and I and 2 golden retrievers did a 3 day weekend in Nov here once, on a single G24. Had to do the jumper cable trick Sunday morning to get the slide in. We doubled our battery bank the next week, and 4 years later switched to dual GC2's. We never needed to do the jumper cables again, and stayed out as long as 8 days off grid. |
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offgrid
Senior Member Joined: 23 Jul 2018 Online Status: Offline Posts: 5290 |
Posted: 10 Sep 2018 at 10:49am |
The heater uses about 2A when operating, so at a 50% duty cycle its going to consume about 24 AH per day, which is half of what a single group 24 battery should be expected to provide. They are about 100AH but you shouldn't take them below about 50% state of charge. So as furpod suggests, dual 6V GC2's in series will give you much better service. That will give you well in excess of 200AH rated, 100 available, depending on exactly what you buy.
When I measured my current draws I didn't see a significant current with all the appliances turned off, maybe a few hundred milliamps at most. That really shouldn't be drawing your battery down much, only a few amphours per day. If you've checked everything is off and are confident your battery isn't really just tired, then you might want to consider buying a multimeter with a clamp on dc current probe. They're really cheap these days. You can use that to determine what your real parasitic losses are and which circuits are causing them. The problem with a battery disconnect is that you do still need to keep the battery on float charge, which the pod charger does for you as long as the batt is connected, so personally I don't see the benefit from having one. That's me. I just leave our trailer plugged in when at home. PV modules are dirt cheap these days and idling a tow vehicle engine or running a genny is expensive and inefficient so I wouldn't hesitate to buy one even for a few days a year, as long as your campsites have good solar access. By all means do also retain the capability to charge from a fossil fuel (TV or genny) source when you run into series of cloudy days.
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1994 Chinook Concourse
1995 RV6A Experimental Aircraft 2015 Rpod 179 - sold |
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mcarter
podders Helping podders - pHp Joined: 07 Apr 2016 Location: Greenbrier, TN Online Status: Offline Posts: 3419 |
Posted: 10 Sep 2018 at 11:35am |
The battery disconnect serves as a convenient way to isolate battery for maintenance or long term storage. I don't use it for anything other than that, but to me it is handy.
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Mike Carter
2015 178 " I had the right to remain silent, I just didn't have the ability." |
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lostagain
Senior Member Joined: 06 Sep 2016 Location: Quaker Hill, CT Online Status: Offline Posts: 2595 |
Posted: 10 Sep 2018 at 12:24pm |
Colorado guy, here's what we do to minimize battery use:
1. We replaced all the interior lights with LED (I was going to replace the outside light that we almost never use anyway, but inadvertently got the wrong bulb - hardly worth the effort). 2. We run the refer on gas when not connected to AC, which is almost all the time b/c we dry camp. 3. We keep the batteries fully charged with our 100A solar panel. 4 We minimize the use of the heater weather permitting. 4. We don't use much of any other appliances or electronics, except keeping the cell phones & macbook charged. 5. We try to pay attention to energy use and turn stuff off when not needed. With these simple things, we really have no issues with running low on DC power. If you want to use things like the AC, micro's, and other high AC powered appliances, your only realistic option is to either go to a camping place that offers AC power or use a generator to run them. Others have commented on the high power consumption of the furnace fan and we've had the same experience. That's why we try to run it only for a little bit in the morning - good blankets are cheap and cozy - and we can recover the loss of those electrons by recapturing some from the good old sun with our solar panel. The biggest problem for us when dry camping is the fresh water and gray water tank capacity. It's easy to use more than you should and run out of water or space for gray water. Again, being conscious of it makes you use less. A good quality deep cycle battery or, better yet - in the view of many - a pair of 6v golf cart batteries will give you all the electricity you need if you combine it with a solar panel and try to conserve energy.
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Never leave footprints behind.
Fred & Maria Kearney Sonoma 167RB Our Pod 172 2019 Ford F-150 4x4 2.7 EcoBoost |
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Colorado r-pod guy
Newbie Joined: 09 Oct 2015 Location: Colorado Online Status: Offline Posts: 14 |
Posted: 10 Sep 2018 at 9:02pm |
Many thanks for all the feedback. I've already replaced all the incandescent bulbs with LEDs. As an aside, my external power meter indicates that one two-bulb light fixture with incandescent bulbs uses 46 watts, while the same fixture with LEDs uses 3 watts. Quite a difference especially if you have several fixtures on simultaneously. We never use the fridge as we use a five day cooler that does the job just fine. The only thing I'm really concerned about is heat during cold weather, which, if we use the jumper cables from the truck method it seems like that should work just fine for a few days. It does make me wonder about putting the extra load on the alternator while out in the boonies, though. IMHO, generators stink. Add the gasoline, noise, yet another thing to maintain, and more weight. Maybe I should just go ahead and get the lobotomy now. Nothing ruins the moment like somebody nearby running a generator so they can watch Gilligan's Island reruns or whatever while we're trying to get some sleep before climbing a 14er the following day. Going solar sounds like a great idea, but there are so many options my head started hurting trying to figure out the most reliable and cost effective way to go about it. Is a 100 watt panel really enough to charge a deep cycle battery in one day if the battery is at about 50% charge? I saw an Airstream a while back and the top was completely covered by flexible solar panels. Obviously they are doing more than just charging a battery... Happy camping to all.
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lostagain
Senior Member Joined: 06 Sep 2016 Location: Quaker Hill, CT Online Status: Offline Posts: 2595 |
Posted: 10 Sep 2018 at 10:22pm |
If you take reasonable efforts to conserve power a 100W solar system can keep your batteries indefinitely charged. Something like this would work fine: https://www.amazon.com/ACOPOWER-UV11007GD-Foldable-Generator-Controller/dp/B01MU4PGLQ/ref=sr_1_5?ie=UTF8&qid=1536635733&sr=8-5&keywords=100w+solar+panel+suitcase&dpID=51A%252BtuB8EgL&preST=_SY300_QL70_&dpSrc=srch
As for generators, yes the noise is awful. You can get duel fuel inverter generators that run just fine on propane. The only problem is there are less electrons in the propane than gasoline so when you convert the fuel to electricity you get less. [For those who take that literally, I'm not serious. I know that the electrons in propane and gas molecules don't get sent into the generator. It's just that there is less energy in the combustion of propane that there is in gasoline.] I never let our batteries get fully discharged as you suggest. It's not good for their longevity. When you camp with a solar system, set it up when you arrive and take it down when you leave and you should have electrons enough to lend to your neighbors.
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Never leave footprints behind.
Fred & Maria Kearney Sonoma 167RB Our Pod 172 2019 Ford F-150 4x4 2.7 EcoBoost |
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GlueGuy
Senior Member Joined: 15 May 2017 Location: N. California Online Status: Offline Posts: 2654 |
Posted: 11 Sep 2018 at 10:33am |
50% discharge on a 12V 100AH battery is roughly 600 watt-hours. On a good summer day below the 40th parallel you should get 6-8 hours of sunshine (no clouds). I generally expect roughly 80% on our panels (we're at 37 degrees north), and we rarely have clouds in the summer. So, 80% at 7 hours gets you a bit over 560 watt hours with a 100 watt panel. Figure out how many watt-hours you use in a day, and see if that is close. Even if it's not quite enough, it could take weeks to add up to a problem.
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bp
2017 R-Pod 179 Hood River 2015 Ford F150 SuperCrew 4WD 3.5L Ecoboost |
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