bad or good battery

[manorlife]

Is there a test you can run to determine if you have a good battery on board? I can get a multimeter but not sure how to test with it sorry if this question has been asked but my search for "battery" "bad battery" and battery test" has yeilded no results. again thanks in advance.

[scrubjaysnest]

The easiest way is take the battery to a place that sells batteries and let them load test it. Many auto parts places will do this.

[manorlife]

Originally Posted by scrubjaysnest

The easiest way is take the battery to a place that sells batteries and let them load test it. Many auto parts places will do this.

I can appreciate that but what I wanted to know is if there is a way to determine this yourself at home? or is loadtesting not possible without proper tools?

I once did some load testing using some very heavy resistors and my ohm-meter. But I wouldn't recommend it unless you're confident in your ohm's law calculations and have the proper resistors. Batteries can generate a lot of current

[Bill]

Is there a test you can run to determine if you have a good battery on board? I can get a multimeter ...

As Scrubjay and Brulaz are saying, testing the voltage of a battery that has no load on it isn't always meaningful. To approximate a load test, you can put the TM on shore power, wait until the battery is fully charged, then unplug shore power. Wait at least half an hour for the surface charge to go away, then turn on all the lights and fans in the TM. Now, with the load of all those lights and fans, measure the voltage at the battery terminals. Set your multi-tester to "DC Volts" or "VDC", put the red probe on the positive battery terminal and the black probe on the negative terminal.

What voltage should you expect to see from a good battery? Here is where it gets tricky - opinions differ. I would expect at least 12.8 VDC, but others will suggest something that differs by a few tenths. I think everyone will agree that if you see 12.0 VDC or anything less, you are probably looking at a bad battery.

By the way, you have asked some good questions, but your Trial Membership will expire before long, and you won't be able to see the answers. I hope you will consider becoming a Sponsor. The rather small fee will ensure you continue to have access to all the parts of the board that you are now seeing.

Bill

[Keith Wire]

Manorlife, you will find out a lot of information about batteries by reading "The 12 Volt side of life", which you can find here.

http://www.marxrv.com/12volt/12volt.htm

I will echo Bill's suggestion about joining TrailManor Owners. It was the best $12 I ever spent.

[scrubjaysnest]

Originally Posted by manorlife

I can appreciate that but what I wanted to know is if there is a way to determine this yourself at home? or is loadtesting not possible without proper tools?

Harbor Freight sells a battery load tester, it won't answer all your questions though. You will need to check specific gravity and correct for battery case temperature after charging the battery. Wait about four hours after charging to get rid of surface charge. All cells should measure very close to each other.

The load tester will show a bad cell but not a weak one which shows up with the specific gravity test.

As others mentioned read and understand the 12 volt side of life.

Also keep in mind you are working with a very strong acid.

My original response was made because I some how got the impression you were looking for a quick check.