House Battery Montoring

[Rockin M]

Is anyone monitoring their house battery charge/discharge activity with any device other than the indicator lights on the panel with the tank monitors. I would like to have a way to better monitor battery conditions. I'm wondering if there is a way to connect a digital device to the existing wiring?

[Bluepill]

Very popular unit:

home - Bogart Engineering

[ScottBrownstein]

Originally Posted by Bluepill

Very popular unit:

home - Bogart Engineering

X2. Great unit and gives you insight to everything that is happening in your RV.

[Rockin M]

Thank you Bluepill and Scottb. I will look them up.

[zs325RES]

I purchased one of these from eBay:


Blue LED 0 4" Waterproof Digital DC 12V 24V Voltmeter Car Motor Volt Panel Meter | eBay

...and mounted it on the front of my Crusader. Effective and inexpensive.

[brucemc]

Likewise - though I installed it in the "Convenience Center" in an unused switch location with a switch & momentary push button (as I couldn't find a SPDT rocker switch with Momentary-Off-On):

[BandJCarm]

Do they not just monitor one battery?

What if you have four 6V instead of two 12V?

[zs325RES]

Originally Posted by BandJCarm

Do they not just monitor one battery?

What if you have four 6V instead of two 12V?

You can use one on each 6V battery, or monitor the complete bank at 12V.

[BandJCarm]

Originally Posted by zs325RES

You can use one on each 6V battery, or monitor the complete bank at 12V.

'swhat I thought, but needed confirmation.

So, the guys above........that have one monitor they've mounted......is that just measuring one 12V battery?? Don't they have two usually?

[BandJCarm]

If you could mount it where you could see it, why wouldn't this work?

Battery Gauges : Cabela's

[ScottBrownstein]

Fundamentally the problem is that monitoring voltage is a real bad indication of battery condition. What most good monitors do (Bogart, Victron, etc) is monitor current into and out of the battery bank. That way they calculate the state of charge using discharge and charge current. First thing is if you have a converter, as soon as you connect, the system voltage will jump to the converter output, just like the LEDs in the panel do.

Conventional wisdom is that you can only even try to predict battery condition if you measure the voltage after all charge and discharge current has stopped for at least 6 to 12 hours and the battery has settled down and all surface charge has dissipated. Even then, voltage remains a very poor indicator of state of charge.

[BandJCarm]

Originally Posted by ScottBrownstein

Fundamentally the problem is that monitoring voltage is a real bad indication of battery condition. What most good monitors do (Bogart, Victron, etc) is monitor current into and out of the battery bank. That way they calculate the state of charge using discharge and charge current. First thing is if you have a converter, as soon as you connect, the system voltage will jump to the converter output, just like the LEDs in the panel do.

Conventional wisdom is that you can only even try to predict battery condition if you measure the voltage after all charge and discharge current has stopped for at least 6 to 12 hours and the battery has settled down and all surface charge has dissipated. Even then, voltage remains a very poor indicator of state of charge.

OK, makes sense but I'm still trying to figure out if that Bogart unit measures one battery only? IF so, do you need two? Or what?

[HopHed]

Originally Posted by BandJCarm

OK, makes sense but I'm still trying to figure out if that Bogart unit measures one battery only? IF so, do you need two? Or what?

The Bogart Trimetric measures the system voltage from a shunt installed off of the negative side of the battery. It will also measure the voltage of a second battery which is usually the engine battery but will not indicate battery drain(amps/watts) or % of charge which it does for the coach batteries. Read the material on it on their web site. Great battery monitor and combined with their solar controller even better.

[ScottBrownstein]

Originally Posted by BandJCarm

OK, makes sense but I'm still trying to figure out if that Bogart unit measures one battery only? IF so, do you need two? Or what?

Bogart will actually monitor two, but only measures current in and out of one of them. That is because when you have a bigger house bank it is usually connected as a single bank of either 12 volt units in parallel or 6 volt units in series and parallel. My RV has 4 12 batteries in parallel and they are treated (charged and discharged) as a single bank. The second Bogart monitor connection is for the chassis battery in an RV and they only display voltage from that unit.

When managed correctly, a bank of multiple batteries can be treated as a single large battery. Sure you might get a bad cell eventually, but that will be long after the bank is ready for replacement. Since Bogart and Victron systems act like bank clerks and only measure discharge (withdrawals) and charge (deposits) it is a good idea to take a look at all batteries and cells every few months with a real hydrometer. This will confirm that all cells are good and that you don't need to equalize your batteries with a 4 hour charge cycle of maybe 15 volts. Few people actually equalize, although Bogart has a companion solar charge controller that has an equalization option and it communicates with the battery monitor for a display and current measurements.

[Randy Ashley]

Is there anyway of resetting the monitor panel lights for water. All mine are reading wrong. Even the storage tank and we are on city water. I have tried turning off electricity and battery power thinking it would reset. It didn't work. I know it's empty. We dumped and rechecked, still reading wrong. Any suggestion or is it in need of shop repair?

[Creativepart]

You are thinking that the monitors are more high tech than they are. There is nothing to calibrate or reset. It is physical water sensitive circuits mounted in holes in the tanks in thirds up the side of the tank. When the fluid level rises it closes a circuit and that activates the light.

TheY do become clogged, broken and unreliable - but there is no logic board to reset.

[Randy Ashley]

That's good to know. We have been on the road a couple weeks. This makes sense. Thanks again. Shirley