Optima makes blue, yellow and red-top batteries. I can't speak for the yellow or red-top varieties but I've been using an Optima blue-top marine battery in the X5 for a year and a half and it's been outstanding. I'm not sure why Gresch felt the need to post (twice) that he doesn't like Optima batteries. Though he's entitled to his own opinion it seems a little slanted since he's never actually owned one of their many fine products.
:flame:

The Optima blue-top runs about double what an equivalent Bosch/Pepboys replacement costs but it is deep-cycle so you'll have all of the associated joys of knowing that you won't permanently kill your battery the next time you leave your lights on or leave your car parked in an airport for several weeks at a stretch. In all fairness I should warn those who are interested in the Optima blue-top that the battery is taller than what is typically installed in an X5. For my particular deep-cycle application (I run a 3000 watt/120v power inverter for power tools), I went nuts and got the 238mm BT DC 5.5I which required me to custom-fabricate 3 brackets to lift the air compressor. Additionally I had to permanently forego having the spare tire installed to make adequate room for the battery. However he Optima blue-top also comes in the space-saving 200mm BT DC 4.2 and the more starting-friendly BT SLI 4.2 also at 200mm. These would be a better choice for those who want deep-cycle capabilities but don't want the headaches of a bracket modification.

Here's some popcorn for the commercial below...:popcorn:

"(Optima) are the batteries that we used on the Warn Glacier Expedition in Iceland. They performed beautifully and seemed completely unaffected by the cold. They worked for hours at a time as we winched the Jeep up and down Hvannadalshnjukur mountain and across Vatnajokull glacier."
Barbara O'Donnell - Peak Communications

:iagree:

My x5 has eaten alive two optimas (red & yellow) and one BMW battery.

After hearing the rave reviews of AGM gel batteries for marine applications, I tried one for the X. Its been over a year and still holding up well.

DEKA Intimidator
http://www.eastpenn-deka.com/default.aspx?pageid=163
http://www.remybattery.com/images/Pr...or_9A34_MD.jpg

I have had a Red Top Optima in my '93 Range Rover LWB and never had any issues at all! It was in my dad's '91 Range Rover for a year before i started to part out the '91 and then i put it into my '93. Starts up fast even in -20 F w/o counting wind chills. One thing about the Optima batteries, if they drain all the way down they can be hard to charge up.

I have heard that Odyssey batteries work good too.



I think when i start to part out my '93 range rover i will put in my red top optima in my X5 (i think it should be the same battery part number).

What is the exact make and model that will fit our X5's at Autozone? I've gone in there and they say they don't have any for our cars. But if i know the exact make and model of the battery that would help out. I have a 2001, 3.0i X5.

One of the big design problems that all gel batteries have (AGM as well as straight gel-type) is that they are EXTREMELY sensitive to overcharging situations. Some manufacturers are reporting that battery life in gel batteries will be reduced by almost 60% simply by charging them .7 volts higher than recommended levels (generally 13.7 volts) and an 80% reduction in life with a 1.5 volt overcharge. This is not an issue with dry cell batteries and is just something to consider when selecting a battery for your particular situation.

Those who have a need for extended battery power (e.g. huge audio systems, 120v outlets, extended storage requirements, and/or harsh environmental conditions) will require a vastly different type of battery than the daily suburban driver in a moderate climate. That said, since battery designs and their corresponding advantages/disadvanges are both material and significant - it's more appropriate to say that a particular design is better for a certain type of application rather than simply saying "brand X sucks, brand Y rules".

My 2 cents...

I just replaced my battery this weekend with the Duralast 49-DL. An online search of Autzone's website doesn't show any compatible batteries, but at the store the guy said it showed that battery as compatible only with the 4.4 (I have the 3.0). Their battery for the 3.0 - don't remember which one - cost another $40, so I just told him I'd try out the 49-DL and come back if it didn't fit. It does. You just move the bracket over to the widest notch, connect the vent tube extension, and you're good to go.

All the batteries at autozone will fit. The battery in the X5 is massive so those batteries simply go in there. They are all smaller than the current X5 battery.

I got one with 950CC and 110 storage capacity. It is smaller than the X5 battery but it is held in place by the old clips.

I run HIDs, DSP + 250WATT RMS Sub just fine. No problems.

It's not a direct fit but you have so much room to work with there that it will fit anything.

2001 3.0

How many of these replacement batteries have that vent hose attachment? Maybe the gel or dry types don't need one, but the conventional ones do.

Thanks, that helps out a bunch...:thumbup: