Checking Battery Charge
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Forum Name: Podmods, Maintenance, Tips and Tricks
Forum Discription: Ask maintenance questions, share your podmods (modifications) and helpful tips
URL: http://www.rpod-owners.com/forum_posts.asp?TID=12544
Printed Date: 02 May 2024 at 5:44am
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Topic: Checking Battery Charge
Posted By: jato
Subject: Checking Battery Charge
Date Posted: 16 Jan 2019 at 9:37pm
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Having had 2 12 volt deep cycle group size 24 batteries for 8+ years I have sensed from many great posts that I need to do more than just trust the "el cheapo" monitor on the wall of my 177. From day one I have used each battery until it reads 1/3 charge then swap it out for the other one. What do you experts out there use to monitor your battery charge, something that a person with limited electrical smarts, like me could use with confidence. Thanks in advance.
------------- 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." |
Replies:
Posted By: furpod
Date Posted: 23 Jan 2019 at 8:01am
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We have just installed an actual voltmeter. In the Pod, I wired it into the bath light circuit, that means it reads just a hair low, due to line losses.. but that's a good thing in my opinion. We added a whole panel of 12v goodness in the new camper. While I like some of the features of it, it only reads in 10ths, and it's voltage monitor is on all the time. It's inside a cabinet, so it isn't a light pollution issue, but if it "on" it's wasting so mA's.. LOL "you can take a camper out of the boondocks..." Rpod.. I think the monitor and push button was about $5 on Amazon. https://postimg.cc/KKM09ctH">  https://postimg.cc/5HzyR8HM">  Lance: https://postimg.cc/phZG0JvQ">  ------------- |
Posted By: offgrid
Date Posted: 23 Jan 2019 at 8:31am
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The "right way" to measure battery state of charge (SOC) is by clocking amp hours in and out. Interpreting SOC from voltage is problematic because it depends on battery temp, current charge or discharge rate, and how long its been since the last charge/discharge. For this reason I don't personally think that a voltmeter is much more accurate than the little red leds in the rPod display are. So far the led display has worked OK for me. Battery monitors that measure SOC/amphours in and out are so cheap now that I'd suggest trying one of those if you want a step up from the little red leds. They all still also monitor battery voltage so you can get that too, and most can give you watts and watt hours too if you're interested in that. Here's one on Amazon, there are lots on there, you could look at the reviews of before deciding. This one uses a doughnut (Hall effect) sensor that you place around a battery conductor to measure current in and out. Others come with a shunt that you need to install in the battery circuit. Then there's one I saw on there that has a bluetooth transmitter so you can read it on a smartphone via an app. No meter to install in your wall or cabinet, as long as you don't mind using your phone. https://www.amazon.com/DROK-Display-Digital-Multimeter-Voltmeter/dp/B07B4CWKRJ/ref=sr_1_2_sspa?ie=UTF8&qid=1548252661&sr=8-2-spons&keywords=rv+power+monitor+panel&psc=1#customerReviews ------------- 1994 Chinook Concourse 1995 RV6A Experimental Aircraft 2015 Rpod 179 - sold |
Posted By: offgrid
Date Posted: 23 Jan 2019 at 8:57am
jato, a second thought for you is that you're already getting much more life out of your batteries than most folks do. Ergo, you're doing something right that's working well for you, so why change it  ?BTW, taking each battery down to 33% SOC individually vs taking twice as long bringing both down to 33% together could be giving you longer battery life if you're recharging each of them right away, because neither battery spends as long at a low SOC charge that way. ------------- 1994 Chinook Concourse 1995 RV6A Experimental Aircraft 2015 Rpod 179 - sold |
Posted By: jato
Date Posted: 23 Jan 2019 at 8:54pm
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Herein lies the problem offgrid. You know as well as anybody that the panel that shows fresh, gray, black water as well as battery strength is not the most accurate and when I monitor battery usage, as I have since 2011 I am using that panel as a stand alone so I am only assuming (and that can get me in a lot of trouble) that when it shows battery at 1/3 charge that in actuality it is. I really don't know for sure, maybe it is really 50%, maybe it is only 20% or less, that is why I feel i ought to having something that is more accurate and reliable than what I have been using. To be certain, it is important to keep the batteries charged, clean, and water levels up to full. Also trickle charging them once in the fall (November) at 2 amps for a day to day and a half each and then again in the following spring (late March or early April) have worked well for me here in northern Michigan. Certainly when temps get down to -32C, as they did not far from us a couple days ago will keep those batteries in "hibernation mode" or kill and crack them, if the charge is not full to near full. Thanks for the amazon link, I will check it out tonight. ------------- 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." |