How To Use An Accurate Voltage Panel Gauge For Diagnostics.

[MEXICOWANDERER]

I'll encourage others start to start off...contribute...share

To elaborate the gauge can detect issues with the electrical/battery system.

The gauge (meter) must be connected to the battery.

[MrWizard]

Right it stops counting watt hrs and amp hours at 100% when recharging
Just charge until charging amps are less than 0.5 amps per 100 ampHrs of capacity
200 ampHr bank, 1 amp charge rate at 14.xx volts
Bank is full
An meter is reset, and you can see your discharge use

[Harvey51]

The eBay one automatically calibrates; just charge until it says 100%. It seems to take some charging current after reaching 100% but never indicates over 100%. A very simple means of calibration after setting the capacity amp-hrs when initially setting it up.

[MEXICOWANDERER]

• Nothing is perfect. Hydrometer samplings are very sensitive to "Lag and Overrun"
• An ammeter is a poor choice for determining resting battery state of charge
• kWh or amp hour meters need regular zeroing and restating of CEF.

Well you can't have everything

[MrWizard]

i put one of those of the 200A version in the previous RV the Safari

a 100A is best for most users, 200A if you have an inverter that can draw over 100A use

750A will be less accurate counting 10-20amp Normal loads
and 30-60 amps avg charging
its a matter of the calibration accuracy of the shunt used for measurement

[Harvey51]

A voltmeter cannot tell the % of full charge because any load diminishes the voltage, any charging increases the battery voltage for at least an hour (I’ve seen well over 13 volts two hours after a short drive in our class C - does that mean it’s over 100% charged?). Why not go straight to a monitor that counts amp-hours going in and out and always displays the per cent of full charge?
Here is one for $40. Some basic knowledge of current and voltage needed to install.
eBay.com

Oh no, I'm infected with that Captcha bug putting up CloudFlare error messages. It happens on ipad Safari and Windows 10 Firefox for the first time tonight. Impossible to post!

[trail-explorer]

MEXICOWANDERER wrote:
To elaborate the gauge can detect issues with the electrical/battery system.

A gauge doesn't detect anything, it displays stuff though.

[time2roll]

There was a picture posted....

[MEXICOWANDERER]

You are absolutely correct. I should use the term FIVE NUMBERS. The meter will register a maximum of 33.000 volts. But rather than involve decimal and fractions I tend to simplify things. But I really should have put a caveat somewhere in there.

Thank you for the correction 🙂

[CA_Traveler]

In addition if I wanted millivolt accuracy I'd question just how accurate in a $5 voltmeter? And it certainly would be less accurate when the power and sense lines are combined and then wired back to the battery. But no problem for bedtime viewing!

[bpounds]

Seems there is confusion about the number of digits. The decimal counts as a digit. A 5 digit reads hundredths of a volt when in 12v range. Millivolts would be a 6 digit. I agree millivolts is not useful in an RV.

[MEXICOWANDERER]

The 3-1/2 digit models I have tried read frequently a fifteenth to two tenths of a volt in error. For five dollars I do not need error. The 5 digit models are frequently within 3 thousandths of a volts with one another. It's all not about thousandths of a volt -- it's about accuracy, stability and money. Heck, tape off the least significant digit if you want. The 5 dollar meters agree with my bench meter that cost 3 thousand dollars in 1995 and was last certified in August 2017 when I had a pacemaker implanted. The bench meter is a 6-3/4 digit unit. It stays wrapped in plastic with a ton of Sodium Polyacrylate powder.

After having purchased perhaps a dozen panel meters and having remained stable over a 7-year period (The BORG) I feel confident enough to recommend them. The 3-3/4" digit Fluke agrees with the Bench meter and the 5 digit panel meter. But a 5 digit rather pricey Triplett meter is in error by 5 hundredths of a volt. And has drifted 4 points. Like it or not I have discovered that power supplies that hunt are not stable and are soon zombies.

[time2roll]

I assume 12.77 would read 12.8 on mine and I sleep like a baby.
Nothing in my RV will get me to 50% by sunrise in these conditions.
Even if it read 12.4 I do not worry.
Mine is an unlit LCD by the door. No way do I want that LED glowing by the bed all night. Too many nightlights in the RV as it is.

[pnichols]

I have a couple of 4-place permanently plugged-in (to 12V receptacles) voltmeters in our MH showing what the coach batteries's voltage is at any point.

i.e. Suppose these voltmeters read 12.77 volts at some point. Every light in our MH is an LED-array one. When I turn on JUST ONE of these LED lights, the voltmeters' reading would drop by one one-hundredth of a volt ... in my example they drop to 12.76 volts.

Why on Earth do I need more coach battery bank voltage reading resolution than this????????

[MEXICOWANDERER]

While being wheeled into surgery for my pacemaker, I couldn't help but notice the six feet wide high definition flat screen above the table.

I have a 32" high definition monitor. Is it rational to believe I could find a high definition camera and mount it on a stiff umbilical mount, or is the notion out of my financial league? Two feet of 4/0 aluminum trunk wire would be stiff enough to maneuver yet stay in place.

This area of electronics is not within my expertise. What would I need besides...



to make it happen?

I just purchased a large PC board mounting fixture to keep the work area steady. Lights are no problem as I have a genuine sunlight grade 50 watt LED chip illuminating the bench and can add another if atomic fireball light intensity is need.

A camera and some way to transcribe the signal to flat screen video input. I am so techno-weak in some areas 😞