Thor Forums

[Beau388]

The house batteries Thor installs in the gas coaches are flooded starting batteries and not deep cycle. As starting batteries, they are made to be completely recharged after supplying large amounts of starting current. For max life, they should never be discharged more than 20% of rated capacity. They degrade (self-discharge) rapidly at 3 to 4 percent per week. They are sensitive to over charging. Most batteries fail because of the coach on the dealer's lot is not plugged in. When the salesmen notices the awning won't work, they recharge the batteries and moves the plug to another coach that need charging. Starting batteries can only take about 4 deep discharges before they fail. Deep cycle batteries are just that, meant to take 400 or more cycles of discharges to 50% with minimum damage. They can be valve regulated (no maintenance) or flooded (removable caps for watering). AGM batteries come in three types just as flooded batteries do: starting , deep cycle and marine. AGM batteries are all valve regulated lead acid (VRLA) batteries. AGM batteries generally have less capacity in amp-hours than flooded deep cycle because of the space taken up by the glass mats and separators; however, AGM batteries can be discharged to 30% of capacity with minimum damage. They have very low internal resistance, so they do not heat up as much when being recharged. Lastly their self-discharge rate is about 1% per month instead of the 1 to 3% per week for flooded batteries. To get the maximum storage amount of wattage into AGM batteries, requires a slightly different charging profile than flooded batteries, but only those than dry camp for long periods of time using solar and generator need worry about the last 5% of a full charge.



I hope this helps with the confusion of why batteries fail so often in motor coaches.