12.6V is hardly low.......
BUT were are you getting that reading?
While hooked up to shore power OR just battery/no shore power?
5th wheel in storage since early Feb.....3 mos of parasitic drain can cause battery to be low.
Then when you plugged in voltage came up....LP Detector beep due to low voltage
2012 LP Detector should not be 'expired' (Usually 5-7 yr shelf life)
Is it time for your medication or mine?
2007 DODGE 3500 QC SRW 5.9L CTD In-Bed 'quiet gen'
2007 HitchHiker II 32.5 UKTG 2000W Xantex Inverter
US NAVY------USS Decatur DDG31