Batteries constantly at 14.7V

[LeCrux]

Hi All,

I have a 150W panel connected to a DUAL battery PWM solar charge controller, which charges two 12v flooded marine batteries.

I live in CT so I kept everything hooked up for the winter to keep the batteries topped off/from freezing.

Upon checking them batteries with the multimeter, they each read 14.7, but the charge controller says it is currently NOT charging because they are topped off. With that reading it seems that in fact they are in fact still being actively charged no?

I am wondering if this sounds as if the charge controller is faulty, and will lead to my batteries being ruined?

[George_SD]

disconnect, measure, troubleshoot. If they are in fact being charged at 14.7 and controller says it's not charging - something is wrong.

[CharlieJ]

Does the charge controller include temperature compensation and if so, is it engaged? Assuming that the boat is outside in the cold, the temperature compensation feature will raise the charging algorithm setpoints to compensate. Might be the answer.

[LeCrux]

No the charge controller does not include anysort of temperature features. Thanks for the idea though.

[sailorboy1]

does the controller cycle? was it just recently on?

[LeCrux]

The charge controller just signals "Standby" which means that the batteries are topped and it is not providing them with additional power. IT is possible that yes, they had just cycled on recently, though I'm not positive.


I disconnected them last week and will check what they are reading tomorrow. I will connect everything back up to get some reading and do some more troubleshooting.

[thomm225]

What type PWM controller is it?

Some of the lower priced Chinese controllers allow the batteries to charge to about 14.4 volts and holds it there.

When I used one of those, I'd allow it to charge to 14.4 volts then disconnect for a few days and repeat. Did this for a few years until I bought a couple other controllers where you could adjust the float.

[roland stockham]

Volts alone only ever tells you half the story. Get a clamp meter so you know what the chare rate is. It is the amps that matter, voltsare just the pressure needed to drive them

[hlev00]

It seems high for a surface charge which is what is read after charging stops with no load but that might be what you are seeing. This link explains https://batteryuniversity.com/learn/...surface_charge

harry

[wrwakefield]

Have you validated the accuracy of the meter you are using?

I’ve had my cheap tool box VOMs go wonky before... new batteries usually fix it...

Just in case...

Cheers! Bill

[seabreez]

Originally Posted by LeCrux

Hi All,

I have a 150W panel connected to a DUAL battery PWM solar charge controller, which charges two 12v flooded marine batteries.

I live in CT so I kept everything hooked up for the winter to keep the batteries topped off/from freezing.

Upon checking them batteries with the multimeter, they each read 14.7, but the charge controller says it is currently NOT charging because they are topped off. With that reading it seems that in fact they are in fact still being actively charged no?

I am wondering if this sounds as if the charge controller is faulty, and will lead to my batteries being ruined?

At 14.7 volts, there is something wrong. In non charging rate and off charge the battery voltage should read 12.8 volts. When the engine is running the charge rate should be 13.2 to 14.7 volts. Having said this 14.7 is at the high end of the charge rate. You are at the maximum. Disconnect the system, wait 30 minutes and check the battery voltage again. It should go down until it reaches 12.8 volts. If the batteries are in good condition, they should last the winter. If you wonder... you could check in 30 days. I never take out my batteries in the fall and they are good to start in the spring time.

[facciatosta]

Originally Posted by LeCrux

Hi All,

I have a 150W panel connected to a DUAL battery PWM solar charge controller, which charges two 12v flooded marine batteries.

I live in CT so I kept everything hooked up for the winter to keep the batteries topped off/from freezing.

Upon checking them batteries with the multimeter, they each read 14.7, but the charge controller says it is currently NOT charging because they are topped off. With that reading it seems that in fact they are in fact still being actively charged no?

I am wondering if this sounds as if the charge controller is faulty, and will lead to my batteries being ruined?

In what way the charge controller says that batteries are not being charged? Shows 0 amps or else?

If there is doubt then in order to find out if battery are being charged or not you need to measure the current with either clamp meter or multimeter in series.

Is calibration of multimeter is up to date?

[Compass790]

As post 8 said check to see if its charging with a clampmeter if you have one.
The recent PWM controllers have adjustable float voltage, have you set it?
You will wreck your batteries if it holds them at 14.7 volts, it will boil them dry if they arent sealed.

PWM solar controllers are cheap as chips, you could buy 2 replacements for $20 & split your feed from panel. Our $10 PWM solar controller is 5 years old & still going. ( actually only cost $1 )
Please post back what you find but yea, I'd suspect controller not going to float.

[Uncle Bob]

Hi, I installed a Morningstar PWM duocharge about 10 years ago for my FLA batteries, with the dip switches set to the correct positions it has been great. Floats at 13.2 and once every 28 days (supposedly) equalises to 14.8.
I know that I could harvest more with a good MPPT, however it is doing its job very well so far, and there more pressing things to spend boat bucks on.

[barnakiel]

To me 14.7 sounds a bit on the high side.


Our regulator tops at 14.4 and then virtually immediately I see the bat and the regulator to drop off to about 13.7.


Are the batteries sound? Is the regulator set for a specific battery 'style' (gels, etc.)