changing from 2 12volt batteries to 1 12v battery

RSD559 wrote:
My little trailer came with one group 27 battery. Two won't fit. So I tried swapping it out for a group 31 battery. Worked great until I plugged the trailer in. It would pop the fuse. Took it in to the dealer and they said that since the battery that came with the trailer worked, all is good. I wonder if it just pulled too much juice to charge. So I charge it in my garage and take it along as an extra. Nothing lost.

Good grief, you can use any size battery you want. Replacing a G27 with a G31 has absolutely nothing to do with blowing a fuse - you had some other issue, perhaps you incorrectly hooked up the new battery which would certainly blow the reverse polarity fuse on the converter.

My little trailer came with one group 27 battery. Two won't fit. So I tried swapping it out for a group 31 battery. Worked great until I plugged the trailer in. It would pop the fuse. Took it in to the dealer and they said that since the battery that came with the trailer worked, all is good. I wonder if it just pulled too much juice to charge. So I charge it in my garage and take it along as an extra. Nothing lost.

So you had ~230Ah capacity with two new fully charged healthy group 27s, and you need to know if 130 AH capacity is enough.

BUt we have no idea how much AH capacity you require, occassionally.

So nobody can answer your question without a bunch of supposition and guessing.

I did go from 2 group 27s in parallel for house, to one group 31 for house and did well in the cycles per $ category.

Now I have one group 27AGM for Both house loads and engine starting.

But I know how many Amp hours I consume/ have consumed and know how low I can go and still start the engine.

I think the point of going to a larger physical size is because physical size almost always coinsides w/ AH capacity.

Yes, a 31 should do the job for single overniters just fine.

The group size isn't what's important...just amp storage...and amp usage.

Moved from Forum Technical Support

For lights the grp31 should easily handle the task, and as long as it is fully charged and in good health it could handle light furnace usage as well.

IF you run your furnace at all? two is better than one.