Batteries (again)

Here's a bit of practical experience from a boat. I had two unused 130AH Trojan's but one was about 2 years younger than the other. Both were maintained.
I did parallel them up to run a small Engel fridge plus the few boat electrics. Charging was from 44W solar panel + a 30Amp DC only genny on many days when the voltage was getting low.
This was intermittant heavy use, totalling maybe 6-8 weeks/year, the rest of the time the batteries were trickle charged when the boat was parked.
The batteries lasted not very long, I guess one of them never got fully charged as it died before the other, got maybe 2 years use out of it, the other lasted another year.

In my experience these batteries take a very long time to fully charge once they have been run down to 50% or so. Certainly, running the tank dry on the genny (about 3 hours) did not do the job, part of the problem being the genny's regulator cutting back the charge from full 30A to 1/3rd or less after a short time. These batteries apparently preferred to be slow charged or having some kind of smarter charger instead the one my Honda genny has built in.

I also found that my Trojans were rather thirsty despite being fed with well regulated charge inputs. I now use sealed ACdelco's and had no problem so far (4 years).
Klaus

Mainey.
I am looking at a Unisolar twin 65w system from the 12 volt shop.
Had a problem on our last trip to Shark Bay with the small genset not keeping up the charging.Battery ended up flat and had a problem for a while. Just thought a second battery would enhance the system.If we are not camped out for more than a night or two we are okay.

Ray, do I understand you have a 105 A/h Trojan Deep Cycle battery and "the small genset could not keep up the charge to the battery"
How "small" is it??

I would first talk with Tony at 12v Shop and explain your geni can't restore the power to the Trojan, I think it's a battery or generator problem, lack of performance and most possibly not fixed by a solar system!

If the original battery is any less than 100% perfect the new Trojan DC when wired in parallel to the original, will loose power to the faulty original battery when they equalise and you will have two x 1/2 charged batteries.