Hi all,
I put an Optima in it shortly after buying my '97 LR Discovery in 1999. The car has tons of power accessories including "Safari" and fog lamps, and a 130 amp alternator on it. So, the battery gets a pretty good workout. The two or three year old "low maintenance" Lucas batt. that was in was fine, I moved it to another car. I preferred a sealed battery in an occasionally off road vehicle.
The Optima was totally reliable for 7 years, then started to go South very suddenly. Talking to the guys at the shop where I bought it (cheaper than anywhere online, plus no shipping cost, but sales tax paid), this is typical of Optimas. They hold up well under hard use, take a charge easily and are "over-engineered". But, when they die, tend to go pretty fast.
The first one worked well, so I bought another Optima for the LR. It's well sealed against spills (great off road) and a couple of those treated anti-corrosion "donuts" on the posts kept the fluffy stuff non-existent for the entire life of the battery.
If I ever add a winch and additional lighting to the Disco, it will get a second Optima installed (there's room under hood if I just relocate the jack and tire chock). But, between the weight of the battery and the winch, I'll need to change the front suspension springs from the current heavy duty OMEs to a set of super heavy duties.
I've considered getting an Optima for my TR4 eventually, when it goes back on the road. I'll be relocating the batt. in the car. Also might choose instead to use two of the 6 volt Optima (or others) that are considerably smaller, hooked up in series, mounted to more evenly distribute weight either behind the seats or in the trunk.
My main complaint is that Optima are darned heavy, even the smaller 6-volt versions. Now, no battery is light weight, although there are some pricey racing batteries that are a lighter than standard (figure $200-400 and up one of for these). But I'm guessing Optimas are about the heaviest batteries around. Practically needed an engine hoist to install one in my Disco, which sits a little higher than stock. Okay, I'm exaggerating, but rest assured you will get a pretty good workout bringing one home and installing it. The weight is also a big consideration if you buy online or via mail order and have it shipped.
Shopping around, I found $130 for a 12 volt Optima locally when I bought it about a year or so ago. There are some other manufacturers offering similar fully sealed, spiral gel cell batteries. Perhaps some are slightly less expensive. But, I don't know if they are as good as Optima. All this type of battery seems to come in a fairly limited selection of sizes.
Cheers!