Battery Issue
Printed From: R-pod Owners Forum
Category: R-pod Discussion Forums
Forum Name: I need HELP!!!
Forum Discription: Perplexed/need help with a problem - ask here
URL: http://www.rpod-owners.com/forum_posts.asp?TID=14469
Printed Date: 13 Jun 2025 at 1:06pm
Software Version: Web Wiz Forums 9.64 - http://www.webwizforums.com
Topic: Battery Issue
Posted By: Ben Herman
Subject: Battery Issue
Date Posted: 16 Mar 2021 at 6:59pm
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Hi all - I could use some help from the wizards in this group on a power issue. We just finished out first trip of the season. Just as we were setting out, I noticed that the battery had discharged down to 10+ volts, after I unplugged the Pod from shore power and was running the fridge on propane just to ensure that everything was working ok. I wasn't worried about it at the moment, because we were heading to a campground with full hookups - something we rarely do. Once I connected my TV to the trailer, the voltmeter was reading 12+V so off we went. I was plugged into shore power the whole 4 days, everything was ok. Same when I plugged the trailer back into the TV, all was reading ok. As soon as I got home and got parked and everything connected, the battery was down to 10 V and small change. The battery is a 12V deep charge marine, I kept it in my workshop all winter plugged into a trickle charger. I check the water levels every few months to make sure all is good. It never gets below 40 degrees, so it didn't freeze. The battery is 3 yrs old. Where I need help is on where to start with trouble-shooting. I assume that I need to take the battery in for a load test. Any other thoughts on what might be causing this? I'm pretty handy but not very literate with 12 v systems, so I am not sure whether/how to test the inverter to see if its not charging the battery. I suspect that it is, since the voltage readings are fine when connected to the TV or to shore power. Any thoughts, Oh wise ones??
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Replies:
Posted By: jato
Date Posted: 16 Mar 2021 at 8:15pm
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Do you hear the fan on the converter running when plugged into shore power? If not I would suspect the converter may be toast. Also, check the plug going into the emergency brake box located on your a-frame. If that has pulled out it will draw your battery down rather quickly. Are you able to individually check the specific gravity of each cell? That would also be a good indicator as to whether it is a battery or trailer issue.
------------- God's pod '11 model 177 '17 Ford F-150 4WD 3.5 Ecoboost Jim and Diane by beautiful Torch Lake "...and you will know the Truth and the Truth will set you free." |
Posted By: Ben Herman
Date Posted: 16 Mar 2021 at 10:08pm
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Thx Jato this is helpful and a good start. I will check tomorrow and see if I hear any fan noise from the inverter. Is that the only litmus test to see if a unit is working? I have a battery tester around somewhere and will see if the cells are all testing ok.
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Posted By: podwerkz
Date Posted: 16 Mar 2021 at 10:23pm
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Initial thought is that you may have a shorted cell in the battery. Was your 'trickle charger' an old school trickle charger or was it a modern 'smart charger' or maintenance charger? I would take the battery to an auto parts store and have them load test it.
------------- r･pod 171 gone but not forgotten! |
Posted By: Ben Herman
Date Posted: 16 Mar 2021 at 10:27pm
| Not sure podwerks - its a pretty inexpensive Harbor Freight unit, so I don't think its old school but probably not top tier either. I'm thinking that I'll pull the battery and see if shore power will run the 12v stuff in the trailer. If it wont power it, then I'm thinking it is probably the power converter. But I'm no 12v electrical genius, so I will have the battery tested also. |
Posted By: offgrid
Date Posted: 17 Mar 2021 at 6:46am
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If you were on shore power for 4 days and your 12v stuff was fine then the converter (it’s not an inverter, which changes dc to ac) is probably ok. Doesn’t hurt to remove the battery and see if it will run the 12v loads without it though. What is the battery voltage while on shore power?
I agree with podwerkz, sounds like a shorted battery cell, each cell is providing about 2V so one being shorted would bring you down from around 12 to 10V. Very common failure mode. Either have someone load test it or if that’s not convenient put it on your charger. Voltage should go up to 13.5 or a bit higher. Leave it for a couple of days and then disconnect the charger. If it drops back to around 10V after a couple of hours the battery is toast. If the charger won’t take it up to 13.5 or higher that could also indicate a bad cell but it could be the charger too. Try the charger on another battery to be sure it actually works. What current (amp) rating does it have? Sometimes it happens, a typical deep cycle battery lifetime is around 5 years, but they can fail sooner. You might had a little prorated warranty left on it you could recover. ------------- 1994 Chinook Concourse 1995 RV6A Experimental Aircraft 2015 Rpod 179 - sold |
Posted By: Ben Herman
Date Posted: 17 Mar 2021 at 9:23am
| Offgrid, on shore power the battery reads 13.7 V. I just pulled the shore power, I'll see what the battery reads in a few hours. Its not hard to pull the battery so I'll take it down for a load test and see if that's the problem. |
Posted By: offgrid
Date Posted: 17 Mar 2021 at 10:49am
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13.7 means your converter is working. Leave the battery disconnected for a couple hours so there’s no stray load on it then check the voltage again. ------------- 1994 Chinook Concourse 1995 RV6A Experimental Aircraft 2015 Rpod 179 - sold |
Posted By: Ben Herman
Date Posted: 17 Mar 2021 at 10:53am
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I disconnected shore power then used the battery to open the slider, voltage immediately dropped to 10 or less. So I've pulled the battery and will take it for a load test. I did this before seeing your most recent message, thanks for responding so quickly! I got my dates mixed up, this battery actually was put into service in 2016 so its not inconceivable that it would be gasping for breath...
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Posted By: Ben Herman
Date Posted: 17 Mar 2021 at 12:10pm
| Battery was toast, picked up a new one and should be good to go. Thanks all for your help. |
Posted By: jato
Date Posted: 17 Mar 2021 at 12:16pm
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What did you find out, was one of the cells really low or was a load test given and just shown the battery to have failed the test? With proper maintenance batteries can last quite a long time. I have a pair of group size 24 Interstates that were built 12/2010 and 3/2011 and get used a lot - we usually boondock. Big thing for us is not to draw down below 60% S.O.C. or 12.2v before charging again as well as keeping an eye on electrolyte levels and fill with distilled water when getting low. ------------- God's pod '11 model 177 '17 Ford F-150 4WD 3.5 Ecoboost Jim and Diane by beautiful Torch Lake "...and you will know the Truth and the Truth will set you free." |
Posted By: Ben Herman
Date Posted: 17 Mar 2021 at 1:10pm
Battery failed. I'm pretty careful about drawdown, I use a solar 100W panel to keep it charged up (we almost always have sun out here in CO). I think that the weak link may be a cheap Harbor Freight trickle charger that I kept attached to it over the winter. Will get a better battery conditioner for next winter.
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Posted By: podwerkz
Date Posted: 17 Mar 2021 at 3:15pm
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Yes, 5 year old battery, and questionable charger.....if it was the CenTech brand from HF those things are JUNK. I would recommend you buy either a Samlex or Battery Tender or Marinco or NOCO charger...they are all decent quality. Anyway, new battery, it should all be working now cuz it sounds like your RV converter unit is fine.
------------- r･pod 171 gone but not forgotten! |
Posted By: offgrid
Date Posted: 17 Mar 2021 at 3:35pm
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5 year lifetime is normal for a deep cycle battery, whether it gets cycled or not. Batteries have a shelf life, which is shortened by warm temperatures and effected by battery chemistry. The lead antimony alloy used in deep cycle battery plates shortens their shelf life but gives them more cycling ability.
Batteries also have a cycle life, and the number of available cycles depends on depth of discharge and on plate design and alloy. It’s a race to the finish line depending on whether cycle or shelf life is shorter. You can think of deep cycle batteries as optimized more for cycling than shelf life, so you wouldn’t want to use them if you didn’t do much cycling, like for example in a starting battery. Bottom line is that 5 year old deep cycle batteries don’t owe you anything, time for a new one. ------------- 1994 Chinook Concourse 1995 RV6A Experimental Aircraft 2015 Rpod 179 - sold |
Posted By: Ben Herman
Date Posted: 17 Mar 2021 at 3:49pm
yes this makes sense. We have very hot summers here and the place where I park my trailer is in full sun. I'm sure the ambient temperature is 110+ inside the battery box. I might consider pulling the battery and storing it in my garage after each use - only takes me 5 minutes to do so. I always thought cold was more damaging but I was wrong! Thanks again for all of the assistance. All now working fine.
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Posted By: offgrid
Date Posted: 17 Mar 2021 at 4:13pm
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Heat accelerates almost all chemical reactions, including corrosion rates. A rough rule of thumb is that reaction rate doubles for every 10 deg C (18F). So at 110F you are getting something around a 4x reduction in shelf life of a battery relative to what you’d get at 70.
But the temp effect on chemical reactions causes batteries to have more internal resistance when they’re cold, because batteries undergo a chemical reaction when they charge and discharge. So they produce less current at a given voltage and need higher voltages to charge properly when they’re cold. That’s why people think cold is bad for batteries. ------------- 1994 Chinook Concourse 1995 RV6A Experimental Aircraft 2015 Rpod 179 - sold |
Posted By: jato
Date Posted: 17 Mar 2021 at 4:23pm
So there is one advantage to living in northern Michigan where the sun goes in hibernation mode for 5 months and weather is oft times dreary and damp - longer battery life ------------- God's pod '11 model 177 '17 Ford F-150 4WD 3.5 Ecoboost Jim and Diane by beautiful Torch Lake "...and you will know the Truth and the Truth will set you free." |
Posted By: offgrid
Date Posted: 17 Mar 2021 at 6:53pm
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Yessir!
But look at it this way, it could be worse. My family on my mother’s side are Yoopers from Ishpeming. Now that’s some cold country. I like SWVA. 73 was the high here today. We get enough snow to know when it’s winter, and enough heat to know when it’s summer, without freezing or sweltering for months or everything turning brown all summer. Just my opinion.... ------------- 1994 Chinook Concourse 1995 RV6A Experimental Aircraft 2015 Rpod 179 - sold |
Posted By: Ben Herman
Date Posted: 17 Mar 2021 at 7:01pm
| By and large our weather in Western CO is beautiful. Just so happens that my back driveway, where my Pod sits, is in direct south-facing high desert sun. So the Pod bakes. But it was high 50s an sunny here today, we had a bit or rain earlier in the week while Denver and the mountains got 2+ ft of snow. I prefer going to the mountains to play rather than living in them. |
Posted By: offgrid
Date Posted: 18 Mar 2021 at 6:29am
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Even if your pod bakes in the afternoon the battery won’t get up to that peak afternoon temp because it has so much thermal mass. It will probably settle out closer to the daily average temp, as long as it’s in the shade. Now if it is in direct sunlight that’s another story... In that case even just painting the battery box white would help a lot. ------------- 1994 Chinook Concourse 1995 RV6A Experimental Aircraft 2015 Rpod 179 - sold |
Posted By: Ben Herman
Date Posted: 19 Mar 2021 at 10:06pm
yes direct sun unfortunately - and no other way to orient the trailer in my driveway. i'll take your suggestion to paint the battery box white, time to break out the spray paint.
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