The charger in your generator does not function if the generator is not running. It takes time to recharge a battery, and you probably have not run the generator long enough to recharge your battery. I've read that some folks have had problems getting a battery to charge with the built-in charging circuit.
recently i install a 17000 gas generator whithout the ats(atomatic transfer switch) and is running great.but a few weeks later after two weekley test the display shows a battery weak signal.the mannual said that there is a built in charger.i am wondering if is in the ats,which i did not use.may i just put an external charger connected to the battery terminals.
I strongly recommend that you use a commercial battery maintainer and keep it connected the battery 24/7. Many folks here use the [url=http://batterytender.com/waterproof-800-usa-western-hemisphere.html][COLOR="Blue"][U]Battery Tender 800[/U][/COLOR][/url]. I use the [URL="http://www.batterychargers.com/ProductDetail.aspx?ProductName=94026717"][COLOR=blue][U]Schumacher SEM-1562A battery maintainer[/U][/COLOR][/URL] to keep my camper's battery up to snuff all the time and I also use a [URL="http://www.batterychargers.com/ProductDetail.aspx?ProductName=94026501A"][COLOR=blue][U]Schumacher SE-1-12S[/U][/COLOR][/URL] in my Generac standby generator to keep its battery charged all the time.