Battery level

[Pooh]

What should my battery level read on the in command system

[markcee]

I may not be phrasing this correctly as it's not my cup of tea, but I believe if you are not plugged in to shore power or any other power source, the display should show the battery's current state of charge voltage.

If you are plugged in to shore power it will display the voltage that your converter/charger is sending to the battery.

Others much smarter than me will be around shortly to assist!

[snoobler]

Originally Posted by Pooh

What should my battery level read on the in command system

+1 to what markcee said. It will show converter voltage which will almost always be higher than battery.

In reality, it doesn't matter much. It's almost completely worthless because it uses voltage to indicate state of charge. The ONLY time it's kinda accurate is if there have been no loads or charging of any kind, and the battery has been at rest for 2+ hours.

[JRTJH]

Markcee is correct. If you are completely disconnected from all power sources (shore power and solar panels), the voltage reading will be the battery voltage, but won't be "accurate" because there will be a "load on the battery" (from the trailer phantom load), which influences the output voltage. Any drain or load on the battery will affect obtaining an accurate voltage from the battery.

If you are connected to shore power, the voltage reading will be the converter/charger output (or the battery voltage if it is higher than the converter/charger which is not likely unless there is a malfunction, but it can happen).

If you are connected to a solar panel, then you'll read either the solar charge controller voltage or the battery voltage depending on which is greater. Cloudy days or at night you'll probably read the battery voltage, bright sunny days if the battery requires a charge, you'll read the solar controller voltage. But, since there will be a load on the battery (if it is connected to the trailer) the voltage will not be "true battery voltage"...

The way to read the battery voltage is to disconnect BOTH battery cables at the battery, let it sit with no connections for 30 minutes and then use a voltmeter to read the voltage at the battery + and - terminals.

[GHen]

A fully charged “rested” healthy battery should be around 12.7
If it shows around 12.2, it is nearly dead and needs to be charged.

If the battery is being charged by shore power or solar it will show between 13.2 and 14.4.

[snoobler]

Originally Posted by GHen

A fully charged “rested” healthy battery should be around 12.7
If it shows around 12.2, it is nearly dead and needs to be charged.

If the battery is being charged by shore power or solar it will show between 13.2 and 14.4.

Just some clarifications:

Resting = no charge or discharge for a full 2 hours or more.

12.2V represents 50-60% on most lead-acid, so it's not DEAD, but it is "dead" in terms of you really don't want to use it any more. If it's the difference between running the furnace to stay alive and keep the belly from freezing, then yeah... murder the battery, but in normal use, 12.2V resting is the "CHARGE ME!" level.

[MurphyIRE]

I went with one of these, problem solved $70-80

[snoobler]

Originally Posted by MurphyIRE

I went with one of these, problem solved
Attachment 38422

Battery monitors are great.

If you want the cat's meow for lead-acid, the Victron smartshunt or one of their BMV units is amazing. It considers both Peukert effect and temperature efficiency and makes for very accurate readings.