OpenRoader66 wrote:
The trailer is only one year old. It came with two group24 interstate rv/marine dual purpose batteries. I'm looking to run my heater fan throughout the night and these die part way through the night.
The heater fan uses quite a bit of current. Think about more blankets or a down comforter and cut back on the heater use.
Its not good to run your batteries down below about 50% as it shortens the batteries life.
Your old batteries probably are rated at about 80 Amp-hours each, total of 160 AH. The T-105s are rated at 225 AH so should last about 1/3 longer. But it sounds as if the old ones were dying rather than just dropping to 50% so the T-105 will probably still be dropping below 50%.