Originally Posted by dcoke
The battery on my 2010 34 rlsa won't stay up. I am plugged into 50 amp. service. Battery tested good.
I'm with Flybob. If by 'won't stay up' you mean that you get full voltage while plugged in, then the voltage, or lights, drop quickly when not plugged in, that means that your converter (110/220AC to 12 volts DC) is likely just fine.
If you battery really is about 5 years old, that's another strike against the battery.
While there are many, many possible causes for this, the vast, vast probability is that you just need a new battery.
You said it was tested? There are two tests. 1) just using a voltmeter, and 2) using a voltmeter and a load, after letting it sit. Flybob's test is closer to #2. If you, or a service person, or battery store person didn't do #2, then it wasn't really tested. I've seen the counter guy a Intersate Battery do just #1 and call it good when a battery wasn't.
You can either take it to a battery place and make sure they do #2, or do Flybob's test. That will tell you whether it's really good.