Trojan Batteries

Ozi,

I have been getting about 18 months out of the normal 75ah deep cycle batteries.

I use it to run the fridge and they get charged with the car charging system.
Everything works well and I am happy with it but when I was at the battery shop yesterday they suggested a trojan and I had heard of them before.

I use the fridge fairly often as I go out bush at least once or twice a month plus I use it when I work off site.
I get a max of 38 hours running the fridge stationary without any recharging.
I have also been thinking about getting solar panels.

Will

We change ourauxiliary batteries every 15 months regardless of condition.
What determines the life of a battery in so many ways, is how the battery is used, maintained and charged. What is a deep cycle battery, basically an old technology design battery with modern technology applied to the construction of the battery, addition of better quality recipe paste, curing of the plates, and the addition of antimony to the lead.
In the way you are using the battery, I would stick with what you have if it is of sufficient capacity, or go to a higher rated Apollo 882 battery which is a Global Yuasa battery made in Korea by the worlds largest battery manufacturer and is reasonably priced, is well constructed, has high percentage of antimony and one of the better value for money batteries.
http://www.apollobatteries.com.au/spec.htm (Very bottom of page)

For example an 882 90aH is about $135 which works out at $1.50 per one amp/hour which is considered good value for money.
A Trojan works out at around $2.00 an amp hour. If the supplier is prepared to give you a two year warranty on that Trojan under the conditions you are using it, then maybe it is a good buy.
Because regardless of brand, how you treat a flooded wet cell is what determines its life. The way we treat flooded wet cells in vehicles, is why they only give you six months warranty on deep cycle batteries used in motor vehicles.
You are also looking at approximately 32kgs over the 16kgs your present battery. A considerable weight increase. That would require a good strong battery tray and clamp to keep it in place four wheel driving.
My philosophy after using so many deep cycle batteries and some damned expensive ones, is to buy good value for money cheaper batteries, flog them and change them every 15 months. In your case they may go 18 months. We change ours because we cannot afford them to fail in the field. Substantially more expensive to fix than the price of a battery.