Battery Indicator Lights

wa8yxm wrote:

CA Traveler wrote:
The lights have only one purpose - for the salesman to explain "what a great monitor system this rig has".

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This is way better

x2. Variants of this exist on Ebay in $1-$3 range. All you need is to locate black and red wire, they are behind the box. You may also plug something like This in cig lighter socket.

Remove your battery meter

Turn it over

You will see something like this

CA Traveler wrote:
The lights have only one purpose - for the salesman to explain "what a great monitor system this rig has".

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This is way better

I do a lot of shopping via wish, it's china stuff for the most part but it should work.

NOTE that voltage is only an indiation of State of charge when battery is RESTING (neither charging nor discharging) A condition that almost never exists inside and RV.

The device is just the monitor panel itself; it is showing you the 12V system voltage (at a very, very coarse resolution). All the circuitry required is in the monitor panel circuit board itself.

Basically, the bottom LED illuminates whenever the check switch is pressed and gives you absolutely no useful information other than perhaps that you do indeed have 12V power. The remaining three lights illuminate when the system is over some preset voltage, as detected by a simple comparator circuit in the display unit. I have not sketched out a schematic of mine to see what it uses as a reference voltage--maybe there's a zener diode or something similar, or maybe even the forward voltage of the always illuminated bottommost LED.

There's no purpose-built ADC or microcontroller or anything at all sophisticated in most of these sorts of panels...though, these days, a little microcontroller would probably be cheaper if one were designing the system anew from scratch. Something like an ATTiny404, currently available for $.55 in single quantities from DigiKey, could easily run one of these monitor panels with four or so things monitored with minimal external components (a voltage regulator, some resistors and LEDs, a switch).

There is probably a circuit board in the control panel that operates the lights off a preset voltage span. I would search for the same control panel and replace it if you can’t find whatever controls just the battery lights. I have never looked behind mine so I’m guessing. I did add a dc digital volt meter where the radio is and prefer it but I would still fix the panel lights.

Had to replace the rocker switch on our indicator panel as it would only work intermittently, ended up replacing them all anyway as it is an older rig. I did order a couple of dc socket (cigarette lighter type) voltage meters that I placed around the interior and outside in converter/dc distribution cabinet of rig, being blue LEDs I can easily see stage of charging with a quick glance.

Easy to install is not what makes it "really inconvenient" - it's all about location, location, location. I would rather spend $40 to get my idiot lights to work (as crude as they may be), just because they are more conveniently located (i.e.: all in one as you might say).

And just to give a little more detail (and to ally the forthcoming obvious answers), the control panel is mounted on the side of a cabinet, within an enclosed space, that has no wire path going anywhere that you could fish a wire into.

wing_zealot wrote:
Let me try again. There must be some "device" (for lack of a better term) that tells whatever controls the control panel to "light one light", "light two lights", etc. What is that device and where is it located?

jdc may have a very good solution that I didn't think of; but, it would be really inconvenient to go that direction.

One of these would be quite easy to install, no shunt needed.

Let me try again. There must be some "device" (for lack of a better term) that tells whatever controls the control panel to "light one light", "light two lights", etc. What is that device and where is it located?

jdc may have a very good solution that I didn't think of; but, it would be really inconvenient to go that direction.

The driver D to A integrated circuit goes bad. You would have to Trace down the part number and hot air change it. There are very few western hemisphere suppliers to purchase specialty ICs.