How long should a charge last?
I got my trailer in July '16. I put new Trojan 6 volt batts in it. It sat down at the Dealer from Oct to early Jan in frigid temps and solar covered with snow while they fixed a bunch of stuff and r...
Forum Discussion
I don't really understand exactly why you unplugged from shore power AND then disconnected your solar panels. Without any way to recharge, the batteries will lose power every day. You have parasitic draw on your batteries that is more than just your CO/LP detector, depending on what your trailer is equipped with. converter, inverter, the radio (even if turned off), TV, Blue Ray/DVD player (if they run on 12 volt) antennae booster, various monitors, USB chargers, etc. In very cold weather, the batteries will lose power even faster.
Did you check the voltage about 4 hours AFTER you unplugged from shore power?
While you were plugged in, the onboard charger could have been putting in the 13.5 voltage into the batteries, but that isn't necessarily what the batteries were holding. You need to let them set for a few hours and then take a reading to get a true indication of the voltage they are holding.
Your math also doesn't add up. You said you started at 13.5 which was probably just the surface charge. You need to let it set for several hours or a day and THEN measure your starting voltage.. A fully charged battery should read at around 12.7 volts. But even if you started at 12.7 volts fully charged and lost .03 per day for 7 days, you should end up with 12.5 volts, which is an adequate 90% charge. Even if you got down to 11.7%, that is a 30% charge and not a death sentence for your batteries, but you should avoid going that low on a regular basis. If you lost 0.3 volts (rather than .03) per day, then you would be at 10.6 volts, which would be a fully depleted battery. But you said you checked it every day. Did the 2nd day's reading read at 13.2 and the third day read at 12.9? Those seem to be very high readings for a 12 volt battery.
As others have said, check the date stamp on the batteries, although it is entirely possible since you bought this trailer new roughly 6 months ago that even new batteries might have a 2016 date stamp.
Did you check the voltage about 4 hours AFTER you unplugged from shore power?
While you were plugged in, the onboard charger could have been putting in the 13.5 voltage into the batteries, but that isn't necessarily what the batteries were holding. You need to let them set for a few hours and then take a reading to get a true indication of the voltage they are holding.
Your math also doesn't add up. You said you started at 13.5 which was probably just the surface charge. You need to let it set for several hours or a day and THEN measure your starting voltage.. A fully charged battery should read at around 12.7 volts. But even if you started at 12.7 volts fully charged and lost .03 per day for 7 days, you should end up with 12.5 volts, which is an adequate 90% charge. Even if you got down to 11.7%, that is a 30% charge and not a death sentence for your batteries, but you should avoid going that low on a regular basis. If you lost 0.3 volts (rather than .03) per day, then you would be at 10.6 volts, which would be a fully depleted battery. But you said you checked it every day. Did the 2nd day's reading read at 13.2 and the third day read at 12.9? Those seem to be very high readings for a 12 volt battery.
As others have said, check the date stamp on the batteries, although it is entirely possible since you bought this trailer new roughly 6 months ago that even new batteries might have a 2016 date stamp.
