Audible battery low warning system? Does it exist?

Where as I do not know of any such device on the market I do know how to build one.. I'd have to do some research but it's a published article, You just need to make one small change.

If you can find one that turns on a light, either a regualr bulb or an LED (Led is best) replace the LED with an opto isolator,,, and use it to control a pizo buzzer, job done.

NOTE: This is how I key my ham radio on occasion,, Computer activates and LED, opto-isolator keys the radio, that way there is no ELECTRICAL connection between the two.

Maybe add a capacitor to the line to buffer the surges when first turned on?

kimberlysmoore wrote:
I've looked online for an audible house battery low warning system and the things that pop up are confusing to me. None of them seem like what I'm looking for..a simple, inexpensive, audible warning when my house batteries get to 50%. I have lights that tell me a general guess but checking them is not always an option and sometimes the "deadly drain" will happen at night when we are sleeping. ...

We have one. Not this, but similar: Voltage Meter with Alarm ($11 at amazon.com).

However, there's an issue that I haven't solved yet, so maybe I can add to the OP's question. Say you don't want to drain the battery to more than 50% (which is about 12.1 volts). But that value occurs when the resting voltage is 12.1 volts, not when the voltage under load is 12.1 volts. So, I thought I'd just develop a table showing the relationship between resting voltage and voltage under load. That, however, is was way harder than I thought it would be. For example, turning on the roof fan causes the voltage to go way down momentarily (due to the starting current of the motor) even though the battery was nowhere near drained. Even measuring the under-load-voltage for simple things (like the interior lights), has yielded a couple pages of notes and no clear relationship between state of charge and under-load voltage. I've also spent a fair amount of time online and haven't found a good source of information.

So in addition to pointing the OP to the right alarm, for those of you out there with alarms and some technical savvy, what voltage are you using and how was it determined?

Skip

Found this one from RoyB
VOLTMINDER model 71730 for $23.
Next paycheck.
Thanks Roy!

Yes it's true but mine doesn't for some reason. The light is burned out as well, however.. I cant remember exact details but my something stops working if CO2 is detected. I hit the reset button on the CO2 detector and the something works again. Once, before we moved into our RV, we had the CO2 detector tested and apparently it works because it is supposed to shut the something down when it "detects".
*my brain is hurting now

Ivylog wrote:
Many CO2 detectors will start beeping when the voltage gets low...not as accurate as a meter.

Many CO2 detectors will start beeping when the voltage gets low...not as accurate as a meter.

Thank you. I've been looking but it all seems so confusing.

MrWizard wrote:
There are many meters on Amazon and eBay that have a voltage alarm function
Just set the low voltage number and when it gets there the alarm goes off

Awesome! Thanks..I will check them out. The bottom one looks familiar but I don't remember audible being an option AND I remember they were expensive. Maybe I'm remembering wrong? I will check again.
*when I type caps I am shouting UNLESS I'm not o.O

RoyB wrote:
I have a home made meter panel that I use to watch the BATTERY LEVELs on when we are OFF-ROAD camping without shore power. When it gets down to around 12.0VDC (APPROX 50% charge level) I get excited and try to get them re-charged again...


This was a favorite meter to get a few years back called VOLTMINDER model 71730. I have one of these in my Truck. I think the company has since then come out with a newer version. This has a settable alarm for low DC voltage...



Another popular unit is this unit... Trimetric model TM-2025RV... They too may have an updated version out now as well...



All photos Google images...

Roy Ken

Our pace is 89.
As far as charging goes for starter battery, there was this 1 time a long time ago when the starter battery died so I started the gene and in about 30 minutes or less, the starter battery was charged enough to start.
Does that explain the system better?
Thanks for the info on mexicowanderer. I will follow up on that.

[qeuote=dougrainer]IF you have the 1986 Pace Arrow, then NO the charging from the genset is NOT the same as the engine Alternator. 1986 means you probably have a POWER CONVERTER(not an Inverter/Charger). A Power Converter does charge the coach batteries but is basically a trickle charger on your year model. The Chassis engine Alternator is a higher amp/voltage charger and will charge faster than on Genset. The Genset HAS NO charger. It powers the Converter, which then charges the coach batteries. As to your quest for an audible indicator. I have never heard or seen one in 37 years as a tech. There is a poster on these forums called mexicowanderer and he has a lot of expertise in aftermarket appliances for electrical items. Maybe he will be able to point you to something you can use. Doug

There are many meters on Amazon and eBay that have a voltage alarm function
Just set the low voltage number and when it gets there the alarm goes off