House Batteries

[CarlParr]

Question. My house batteries are 18 months old, but will not stay charged like they did before. I had them load tested and they passed just fine. However, I am wondering if load testing house batteries requires a different meter/test then the normal one provided for car batteries. I, admittedly, did abuse them by sometimes leaving the inverter on and such. Until recently it was a daily driver. Or is there a chance the inverted is bad. It is the original in a 2007 Sportsmobile. Suggestions on testing the inverter? I appreciate all your thoughts.

[daveb]

Sounds like you're saying is they go dead after some period of time while the van sits idle.

When you start the inverter charge you should hear the separator click close as you apply a charge. This also happens when you start the vehicle. I'd make sure the separator is working correctly first off before jumping into the inverter. You should see the voltage jump into the 13.4-14.5 range with the engine running or the inverter is activated to charge. Start the vehicle and check voltage on both sides of the separator and note the voltage differences. You can do the same with the inverter. If you don't see a 13+ voltage on both sides of the separator, the separator may be the culprit.

What kind of batteries did you install? Same brand/type that you had before?

[BrianW]

Yeah I was going to say check the separator since it’s 12 years old at this point. If it’s a daily driver it should be keeping the batteries pretty well topped off if current is flowing from the alternator back.

[Scalf77]

So there is a different test for house batteries. Remember a deep cycle battery has rating for capacity. This is usually referred to as the 20 hr capacity. That means for a battery like the Lifeline 4D which has a 210 Amp-hr capacity that it can take a 10.5 amp discharge for twenty hours (210/20).

You could take the batteries to some place that perform this test, I would try marine repair locations. It generally takes an electronic load, and temperature controlled water bath (battery should be at 77°F)

The fact that you said you admittedly abused the batteries would lead me to believe that you are experiencing normal capacity loss. Since it was a daily driver, I expect that it's main charging mode was through the alternator, which will take off some capacity in it's own right. You have probably also left the battery in a partial state of charge causing sulfation and accelerating capacity loss.

You should invest in a good battery monitor, and also make sure you have a switch to turn on your inverter only when you need inverted power. And then come up with a good charging scheme.


more information can be found at these links

https://www.practical-sailor.com/iss...s_11689-1.html

and the results

https://www.practical-sailor.com/iss...s_11691-1.html

-greg

[REF]

Do you have solar? If not, this will maintain your batteries when sitting idle and help battery life and longevity. But I agree, your separator or isolator might also be shot.

[Lilnuts2]

Here is a great article about house batteries. It does have solar info in it also. Just a good read in general.

https://handybobsolar.wordpress.com/...ging-puzzle-2/

[CarlParr]

Thank you all for your responses. No solar. I have had it charging at home on shore power for a few days and it is sitting at 14.4. No load so I am going to see what happens.
Thank you Lilnuts, that was a good read.

[Scalf77]

Originally Posted by CarlParr

Thank you all for your responses. No solar. I have had it charging at home on shore power for a few days and it is sitting at 14.4. No load so I am going to see what happens.
Thank you Lilnuts, that was a good read.

So you have now peaked my interest more, I would not suspect your batteries to be sitting at 14.4 volts after a couple of days of charging. That voltage would be inline with the absorption phase of the charge cycle, which would mean it is not completed a charge cycle if your charger is providing a three stage charge cycle. I would have suspected that it would have completed a cycle after a couple of days.

How and when it completes that cycle is some-what dependent on the inverter/charger. Also the voltage output may be compensated by the temperature of the battery, a very cold battery could get you to a higher float voltage . A normal float voltage is around 13.3 -13.5 volts. Once you unplug the charger the batteries should go down and settle in around 12.8 volts.

More help could come if you were to give more info on the equipment in your rig.


-greg

[jimtmcdaniels]

Those batteries are still so very new, I wonder if your charging system is the right profile type(charging voltage and speed and top off voltage) your battery type requires.
Or perhaps the batteries are getting sulfated.
That’s what I found with my old battery fix Read below:


On a side related note:
I’ve noticed that batteries seem to last for less years than it should when in my mind, our new batteries should be lasting more years than our old batteries of the decades past due to improvements. Hmm...

1. Before you decide to replace old batteries, they might have life left in them.
I’m a true believer now I’m using a $20 electronic desulfator by cleanpowwr I got online A 2ah on eBay but they are also on Amazon the reviews are generally fairly positive, some amazing.
These are so super cheap but seem good quality and it automatically detects the voltage of the battery but have a manual button to set the voltage for weak battery’s it might not detect.
The small alligator clips are a bit of a challenge to get to clip on the large terminals.
One of the alligator clips came off and I had to resolder it but after it was fine.
Somewhere I read that the 4ah might be too strong for doing only 1 battery but good for doing a bank of batteries.
Because my car battery in my Buick that I drive almost daily, died after not much cranking one morning when trying to starting in this winter.
Battery is about 5 years old.
So I charged the battery and then disconnected the charger and one of the car terminals and connected the desulfator to the battery terminals and left it on for a day.
The desulfator creates high voltage pulses through the battery plates to break down the age related sulfation but drains the battery while doing so
I then charged the battery again and repeated the desulfator.
After like 3 days of this process, the battery has been like brand new and cranks strong and long even in the bitter cold days we have had.
Maybe they should call these desulfators viagra for the battery!
Saved me from having to buy a new one. I hope it lasts but as strong as it cranks, I feel it’s got years and years left.
So I’m now making it a yearly thing(I set an annual reminder in my phone calendar to nag me!) to do the desulfator to all my vehicles for one day for preventative maintenance and we will see how many more years it adds!

2. I’ve started installing battery blankets on all my batteries.
After reading how blankets protect batteries from damaging temp swings especially under the hood with the heat producing engine.
My friends get blue apron meals all the time and the silver reflective bubble wrap bags the food is in is perfect and free and has no aluminum so will not short anything.
I just use box tape and fold and cut to size and trim flush to the top edge and pole holes at the bottom for drainage if needed.

That’s all I knows!
Take care!