Battery meter

[hoggsback]

Isn't there something I can attach to my battery or plug into a 12v outlet that will tell me the status of my battery charge? Something that has red, yellow and green status lights or similar to tell me to charge my batt before I have it go dead in the house.

[Stringerless!]

Hoggsback, I had one in my hand at fleet farm a few hours ago. Could not justify spending $28 and change for one. They had batteries on sale for 19.99 for 9amp and 16.99 for 8 amp.

[hoggsback]

I was looking on the Northern site but can't seem to find what I'm looking for. A buddy just told me that Minnkota makes a small one so that is what I'm searching for now.

[walleyesforever]

Fish House supply has a nice one that plug's into the 12v outlet and has a nice led read-out

[hoggsback]

Perfect thanks.

[hondarider550]

I purchased a small Minnkota battery tester that you just hold on your termals every once in a while. I think that i bought in on clearance from walmart for only 5 or 7 dollars. Im sure you should be able to find something like that in any equipment store.

[backlash 1]

Another option is if you have a digital multi-tester at home just check the battery with that. Very accurate, and no cost, if you have one.

[hoggsback]

I have a couple of "testers" at home but don't know how they work and have never used them. They came in a package and I wanted 1 thing out of that package. I will have to look at them to see if they will work. They are the type with the needle window and various settings on a switch.

The best option I see would be a unit that has a 12 volt plug in that you can insert into your outlet and it will tell you the voltage, etc. Simple and easy to use.

I will check into the Minnkota type model at the big W if my other "testers" won't do it.

[aanderud]

Any volt meter will do, you can get cheap ones for 5 bucks or so. The trick if you are using a voltmeter is that you don't get "red/yellow/green", so you need to know what voltage corresponds to "full" versus "50% full" versus "nearly empty". Most multimeters I've seen have probes that will fit inside most any standard outlet, so they should suit your needs just fine. If you are near a harbor freight, I know you can get uber cheap ones there, just google the phrase "7 Function Digital Multimeter" for a sampling.

Here's a chart that you can use to translate voltage to charge fullness (assuming 12 volt battery, of course)

[hoggsback]

Thanks for the chart, I believe I can use my tester w/o buying anything else. If I am getting into the 11 volt range, time to bring the batt home for the charger.

[hoggs222]

Interesting! I would've never though that 12.06 V would be considered half charged or gone (depends on glass half full or half empty!). I'm going to print this out and keep it in the fish house!

Isn't there some manufactured kind of charger I can plug into my trucks 7 pin to charge the batteries? I think it was drive and charge or something?

Another question, if you get to a certain point, does it start draining faster?

[aanderud]

There's a fair amount of technical detail regarding charges and batteries. Many variables to consider, including temperature, etc.

I got that chart from a random RV enthusiast's HSOforum. The values were somewhat imperically derived from his own experiences. You can read about it here:

http://www.ccis.com/home/mnemeth/12volt/12volt.htm

Some of the interesting points:

Quote:

it's also important to note that the battery voltage will be affected by temperature.... The chart above, and most other ratings applied to Lead/Acid batteries assume that the battery is at room temperature: 21 degrees C or about 70 degrees F. As the temperature of the battery drops, so will the fully-charged voltage reading. I have found a lot of conflicting information about this phenomenon, but it seems to be safe to say that for each 10 degrees F drop in temp, you can expect to see the voltage drop about a tenth of a volt. (.10 volt) That means that a battery at 32 degrees F with a no-load voltage reading of 12.35 volts is fully charged