New group 29 battery with low specific gravity

hook it up to the old sears charger and let er rip overnight, as in 12 hrs. retest.

after further reading your old sears charger ain't as old as I thought!

No it is supposed to bubble while charging once it gets closer to being "full" Yes, let her rip on the manual mode and spot check the SG till it stops rising. You can shut it off for overnight and start again in the morning. It is cumulative.

Thanks for the inputs. I've seen one of those threads and much of it was over my head. I'll look for the other.

My charger also has a manual button and it puts out 14.5 volts. It sounds like I need to do that until it comes up, instead of the auto deep cycle.

Is there a time I should set it to that or do I need to watch the specific gravity and stop when it's at 1.265 or higher?

One of the threads talked about "boiling" which I think is when it's bubbling while charging... is that something I need to be concerned about?

The thread by land yacht is titled "My screwy 31"

You need a charger that will stay on the job for a few days, not an "automatic" that shuts itself off after a few hours. Your trailer's converter is one. Leave it on that charger for a few days and then check SG again.

You could really use a "manual charger" that gets the battery up to 15v for an "overcharge" but you need to unplug it yourself when it gets the battery voltage up there. Then leave it on the converter for a few days and then check the SG.

However if you have only those two chargers, try it with converter first before rushing out to buy anything.

How many volts is your charger putting out? The sg will probaly come up but it may take days if the voltage is only 13.6 or so. You will get a faster charge at 14.4 to 14.8 and you may also need to top charge at 15 plus volts to drive the SG up. There is a good thread by landyacht about his gp 31 battery that is a good read.