Simple Battery State of Charge Capacity Voltage Test

[Gonefishin]

Good info. Easier than carrying around a portable volt meter. Let us know how long it takes to arrive from China. (or did you already receive one?)

[planovet]

Simple way of knowing State of Charge

http://cgi.ebay.com/Red-LED-Volt-Meter- ... f7bf1#shId

Led panel voltmeter with only two leads, no seperate battry needed, resolution is to .01 volts, dimmable
simply connect this panel mout meter ground and plus to proper terminals and thats it, draws 30 milliamps full brightness and 13 milliamps dimmed. When voltage begins to reach 12.2V its time to charge battery. Cheap $9.99 dollars at ebay

I have a similar voltmeter that I got off ebay. Looks the same only mine is not dimmable. I'm very happy with it.

[astrotrailer]

I have been using a DocWattson meter for about 3 years to track power usage. It gives real time
voltage, current and power. It all tracks cumulative amp hours and watt hours, peak amps and
minimum voltage.

I first started using it when I wanted to power my computer and telescope for multiple nights and
I didn't want to discharge the battery below 50% capacity. The cumulative amp hours reading was
very helpful. This summer I moved my 130 amp/hour battery into my cargo trailer and added solar
so I used the meter to track the amp output of the solar panels. I only use my trailer off the grid
since I dry camp where it is very dark for astronomy.

Here is a link to the meter.

http://www.powerwerx.com/tools-meters/doc-wattson-meter-dc-inline.html

It costs more but it does a lot more.

Jeff

[caseydog]

The battery in my car is the original battery. It is five years old. It has failed two load tests. It should already be dead.

I should have already replaced it, but I'm looking at it now as a challenge.

I know it is going to fail on me -- probably when I have plane to catch. But, I can't help wanting to see if it can make it to six years.

Maybe I should get a back up for that inevitable failure.

CD

[BC Dave]

somewhat on topic ... I replaced my car battery with a marine deep cycle battery that i had been using for an electric trolling motor that wasnt getting much use; car battery died so I just replaced it with that one .... got busy and noticed that the marine batytery was getting weak ... ment to check it ... but didnt have a chance untill I was in a hurry and it failed ... so took it out and over the weekend checked it ... it read 11.7 V! Yipes; I looked inside and couldnt see any liquid in any cells (i know stupid is a s stupid does; I was busy ...grrrr) .... topped it up with distled water and checked the voltage and "Voila"; was shocked (pun lol) to see it read 12.7 V! .... set it on the charger and it seems to hold a charge; also set it on high 10A charge for a couple of hours to boil off any scale on the plates ...

Comments thoughts; will it be as good as new with the abuse it went through? (will post this in the electrical section too ...)

[Steve_Cox]

The battery in my car is the original battery. It is five years old. It has failed two load tests. It should already be dead.

I should have already replaced it, but I'm looking at it now as a challenge.

I know it is going to fail on me -- probably when I have plane to catch. But, I can't help wanting to see if it can make it to six years.

Maybe I should get a back up for that inevitable failure.

CD

Sorry to continue the thread hijack, but.......

Our 5 year old Honda stopped passing the load tests at the Dealership about a year ago. I always bring it home and put the old fashioned battery load tester on it and it passes. What gives????

Back to the topic. I put an analog panel meter in the teardrop and none in the gypsy trailer. I seem to know when the battery is low, the lights dim or the exhaust fan slows down. I have a power converter but when there is no 120 volts available, I'm gonna use the 12 volts, til I use it up.

That is a nice digital meter however, I might have to have one