Remote Car Battery Voltage Monitoring

Don't know about ready to use products. They sell some cellphone remote module by some electronic stores. It could by connected to alarm system and other surveillance device or circuit.

Regards,

Ralf

Voltage is not an adequate measure of the battery state. A battery needs to be checked under load. Temperature also affects both the voltage and state of charge.

I th>Anyone have ideas or sources for remotely monitoring an infrequently used

You might not need to get that fancy, try something like

just put it on the dashboard, plug it in, and stop worrying.

Look around a little, that was the first l> Justr get one of these

I have a car at a second home that sits for months without use and a marine battery that sits in a small sailboat to power a bilge pump and lights. For the boat, I found a flexible, waterproof solar panel at West Marine that keeps the battery fully charged. In 4 years I've never had to charge it with anything else. For the car, I use a Battery Tender Jr. to keep the battery "ready-to-start" and it works well. Rather than monitoring the battery's condition remotely, in both cases I just use the chargers and never have to worry about it. If the car has a lighter socket, power outlet that's always on you can just plug it in that way.

shows the Battery Tender Jr. and you can buy it for under $30 at places like Pep Boys.

With the low current needed for a trickle charger, just wire it to a cigarette lighter plug and drape the wire across the steering wheel. It would be hard to drive off without noticing it.

Another solution would be to wire a 3 wire 1/4" phone plug to it and a jack to the car in an appropriate location where it will unplug if you drive away. Connect the 3rd terminal to get power from the car's jack and use it as a safety circuit to shut off the charger if it is not connected.

A lot easier, more reliable, and cheaper than monitoring the voltage and calling your cell phone.

Why go through all that bother? Look on ebay for a solar panel. There are a ton on small units that VW uses to keep the batteries topped off while the cars are in transit. They are small 5-10 Watt units. Usually go for about $10. Lay one on the dash and park the vehicle so the windshield is facing south. The unit has a cigarette lighter adapter and you just plug it in.

Scott

Robert Green wrote:

That's a good point. Still, voltage is better than no data at all in trying to figure out whether the battery needs a charge. There may be something wrong with the the onboard electronics in the van because the battery has lost its charge twice in the last two months. I'm going to have to monitor the standby current draw for a few days.

I bought a solar panel charger today that clips to the visor. I think it's unobstrusive enought to be workable for dad. I am just not sure it will deliver enough current to be useful.

That's a great idea but it's more ambitious than I would like, especially tapping into the starter circuit. We'll see how the solar panel works out. If that fails to solve the problem, I'll look at other potential solutions.

Thanks Dave! (110)

-- Bobby G.

I got something very much like it that clips to the sun visor and plugs into the cigarette lighter. We'll see if it does the trick . . .

-- Bobby G.

I just bought a solar panel that plugs into the dash. We'll see if it works. The van doesn't get a lot of sun where it's parked and the rear windows are all heavily tinted so mounting it back there won't help much. I may still have to go with some sort of detachable umbilical because I need to be able to charge his scooter while it's in the van, since he still walks from the van into the house with his cane.

Thanks for the info. Hopefully the dash charger will do the trick.

-- Bobby G.

I've thought about that as well as the solar panels but the car's parked in an area that gets very little sun. My damn toothbrush can recharge without any wires - why can't the car (aside from the massive size difference!)?

This is probably the most appropriate solution. I especially like your idea of wiring it so that if it is accidentally disconnected via a "drive off" that there won't be a live 12VDC plug lying in the driveway. I was also thinking of affixing the charging cable to a spring-wound reel so that when disconnected, it would retract into the reel housing. Not sure where to find one for 12VDC charging wire, but can probably make one from a retractable clothesline pulley.

The one downside to this solution is that sometimes, depending on weather and other factors, the van is backed in, not nosed in. I suppose recharge connectors on both ends would solve the problem. I think I'll end up getting RV connectors because another issue cropped up yesterday - the need to recharge his 24VDC powerscooter while it's sitting in the van. That means at least 4 separate conductors going to the van in addition to any supervisory wiring that I might need. My concern for those would be to waterproof them and make sure they didn't get clotted with road slime and become useless.

I'm still not giving up on the cell phone notification. It will tell me if the car charger wasn't plugged in to begin with! Whatever I do, I think I will incorporate the ability to determine whether the car is plugged in and if, so, what the charge level is.

Thanks for the insights, Bill.

-- Bobby G.

Which one? That URL points to a whole page of items!

-- Bobby G.

That's the plan for now. Hopefully it will end the problem of run-down batteries. I may still need to go the "plug in" route because I want to also be able to charge my Dad's 24VDC scooter while it's loaded in the van.

-- Bobby G.

A possibly easier alternative would be to use a different connector. Like the Anderson Powerpoles. This too would disconnect via "drive-off", but it wouldn't accidentially short the 12V charger if the plug happened to land on a piece of metal. Yet you wouldn't have to worry about the loose plug on the van end shorting the battery either.

Hi Bobby:

Make sure the dash charger is putting out more current than the "on board electronics" require. If, for instance, your total current draw is greater than the dash charger can supply, you're going to wind up in the same situation (dead battery). Additionally, (and at night time) the current draw on the battery is going to go back to "normal", and the charger may not be powerful enough to "keep up".

I found this in a "Froogle" search:

"Frank Olson" wrote in

Thanks for the heads up.

Has a discussion of just that potential problem and how to trace it. The process is woefully very much like hunting down a bad X-10 device or telephone extension. Out comes the clamp ammeter.

-- Bobby G.

You're welcome. I figured this solution would be the best for you because you could also install a jack to charge your dad's chair and the output is a "tad" higher than the solar charger option. You'll need an automatic isolator, but that's a snap to find and install as well. I know you're not in Canada, but a store by the name of Canadian Tire

has one (search on "battery charger" in "automotive").

In my experience, the "clamp" style ammeters aren't all that accurate when it comes to reading small currents. I like my digital multimeter and doing things the "old fashioned" way. :-)

Mind you, it'll mean you'll have to reset your dash clock and reprogram the radio buttons, but I figure you're more than capable. ;-)

Frank Olson