Losing Voltage

[MrZip]

I'm currently camped (plugged in to 30 AMP) shore power. I've been plugged in for two weeks but have noticed the past few days I'm slowly losing battery voltage off the coach batteries. How can I tell if this is a battery problem or a converter problem i.e. not charging correctly. BTW batteries are excide deep cycle and 1 year old.

[Beau388]

Go to the WFCO (World Family Company) web site and load the trouble shooting for the WF-8955 power center. The WFCO is the most common converter charger used by Thor in recent years.

With the converter on check the voltage output at the power center. These will be the large wires coming from the charger/converter going to to the 12 volt fuse panel. It should read 13.5-14.2 volts. If that good, it is NOT your converter charger. Next with the converter charger on find the battery charging cable in the battery compartment. It will be a fused #6 cable. Disconnect it and check the voltage. It should read 13.5 to 14.2 volts. If it is about 1.6 volts you have a bad battery charging relay.

[TurnerFam]

why do you think you are losing battery voltage?

[scrubjaysnest]

The WFCO is not capable of charging the Exides properly as I have never seen one go above 14.2 volts. If you check the manufacture web site the Exides require 14.8 volts for up to 12 hours to complete charging in absorb mode. The absorb voltage for the WFCO is 13.6 volts which is the float level voltage for the Exides.
When on shore power I use an automotive smart charger that will reach the required voltages.

[Beau388]

2.25 volts per cell will fully charge any lead acid battery (13.5 v for 6 cell battery). That's how a floating charge keeps the batteries fully charged. More voltage, the faster the charging rate and the hotter the battery gets when being charged. Generally the max CC/CV charging is 2.40-2.45 volts per cell. While this higher voltage does shorten battery life, it is deemed as acceptable to shorten charging battery time. Any lead-acid battery should be charged with a max amperage of 10% of AHr rating for max longevity. Typically this is 10-15 amps. AGM batteries require slightly different charging schedule to their very low internal resistance. I would suggest that the WFCO charger not be used with AGM batteries as it is optimized for flooded lead-acid batteries.

[MrZip]

Thank you all for the good information. Turns out I had accidently hit the battery "store" switch. Obviously the battery cannot charge if disconnected. Once I turned the switch to "use" the Voltage immediately started to rise. As mentioned the WFCO may not put the full 14.8 volt charge but 14.2 I think will be ok.