Battery Gauge?

Is there anyway to tell if the battery is low.

I like to play music in acc at the beach and would like to know if the battery needs to be recharged.

It looks like the auto power off feature turns off after 20mins but doesn't take into account the battery level.

 

You can get cheap voltage gauge that plugs into cigarette lighter

 

Get one of these:

LCD Cigarette Lighter Voltage Digital Panel Meter Volt Voltmeter Monitor for Auto Car Truck PatternName: 1piece

www.amazon.com/Cigarette-Lighter-Voltage-Digital-Voltmeter/dp/B0092KVYGI/ref=sr_1_4?ie=UTF8&qid=1453657920&sr=8-4&keywords=12+volt+power+gauge

 

I have a 1000 amp jump box so I don't get stuck in the middle of no where. It will also power your electronic devices so you are not running down your vehicle battery. The 600 amp in the link below is only $43.70. This might work unless you are trying to blast the sound system in the vehicle.

http://www.target.com/p/peak-600-amp-jump-starter/-/A-15130590?ci_src=17588969&ci_sku=15130590&ref=tgt_adv_XS000000&AFID=google_pla_df&CPNG=PLA_Automotive+Shopping&adgroup=SC_Automotive&LID=700000001170770pgs&network=g&device=c&location=9052941&gclid=CKzQhoXCw8oCFQZsfgod9_gHkw&gclsrc=aw.ds