I've installed a couple of electronics recently and I'm having to jump my battery more and more since. I've read the Optima yellow top batteries are great for cars with added electronics, but I understand it may have to be custom installed/fitted. Which Optima battery is best or easiest to custom install for a 2010 supercharged?

I think you'll be lucky to get an optima battery to fit full stop... the range rover batteries are derived from BMW and as such they tend to be long and shallow... where as the optima batteries are regular shape and rather tall for a ffrr.

Some of the chaps over here have fitted a second battery in the rear compartment... it should be your passenger side, but suffice it to say the opposite side to the dvd / nav / tv/ radio . You might be able to get an optima to fit there, but again it's set up to take a BMW style battery.

FYI in my Jeep days the Yellow top Optima batteries were considered the best all-rounders  Yesterday I couldn't spell Engineer... Today I are one!
Inventor of the 'Guide-o-Matic automatic wheel alignment tool'
Former long term L322 owner, Up/Down graded to a Classic Tractor!

Have a look at this

http://www.fullfatrr.com/forum/topic26065.html?highlight=battery Yesterday I couldn't spell Engineer... Today I are one!
Inventor of the 'Guide-o-Matic automatic wheel alignment tool'
Former long term L322 owner, Up/Down graded to a Classic Tractor!

Hmmm... what about another make and model battery that fits and does well starting up with extra electronics installed?

miggit wrote:

Some of the chaps over here have fitted a second battery in the rear compartment... it should be your passenger side, but suffice it to say the opposite side to the dvd / nav / tv/ radio . You might be able to get an optima to fit there, but again it's set up to take a BMW style battery.

FYI in my Jeep days the Yellow top Optima batteries were considered the best all-rounders

How big do you want to go?

You can already get a 110Ah battery under the hood and fit the same in the back and you'll have 220 Ah, any bigger and you'll be robbing a big rig for a battery  Yesterday I couldn't spell Engineer... Today I are one!
Inventor of the 'Guide-o-Matic automatic wheel alignment tool'
Former long term L322 owner, Up/Down graded to a Classic Tractor!

I currently have a Interstate Batteries MTP-49/H8 100AH which is listed as 900 cranking amps and 730 cold cranking amps, so anything more powerful than that or that will stand up to a car with a lot of electronics.

Right there are a few things that you should know, Firstly your battery is a lead acid battery... ffrr's should have a calcium battery
Second, the highest output Optima battery is 75Ah...... the ffrr V8 std battery is 90Ah, but you can also get 100 Ah and 110 Ah batteries in the same case size.
Thirdly, Optima batteries are AGM (Absorbent Glass Matt), you can get AGM batteries to fit the ffrr only they are 90 - 110 Ah or put it another way 20 - 46.66% More power, delivered in the same way

My recommendation would be to get a 110 Ah AGM battery and try it, if your still having problems add a second in the boot, sorry trunk

FYI Bosch and Varta batteries are rated highly over here  Yesterday I couldn't spell Engineer... Today I are one!
Inventor of the 'Guide-o-Matic automatic wheel alignment tool'
Former long term L322 owner, Up/Down graded to a Classic Tractor!

So what's the number I need to pay attention to if I want the vehicle to start up reliably with extra electronics installed: capacity, cranking amps or cold cranking amps?

The higher the Ah the larger the capacity, and it will therefore last longer.... The important thing is to try and get a AGM battery, over here they are 020 size... but I have already discovered that doesn't translate into American, in fact I had trouble finding anyone selling batteries over there full stop What in Gods name do you call a battery your side of the pond?

Over here, if you type 020 in to the bay of fleas you get pages of batteries... tried that on fleabay USA and got zip  Yesterday I couldn't spell Engineer... Today I are one!
Inventor of the 'Guide-o-Matic automatic wheel alignment tool'
Former long term L322 owner, Up/Down graded to a Classic Tractor!

This is the type of battery that will give you the most power for the longest time, AGM are also called stop start batteries

https://www.tayna.co.uk/Exide-020-AGM-Car-...P9582.html

https://www.tayna.co.uk/H15-Varta-Start-St...P8824.html

http://www.alpha-batteries.co.uk/stop-star...r-battery/

http://www.alpha-batteries.co.uk/stop-star...ery-s5a13/

http://www.alpha-batteries.co.uk/stop-star...ery-s5a15/ Yesterday I couldn't spell Engineer... Today I are one!
Inventor of the 'Guide-o-Matic automatic wheel alignment tool'
Former long term L322 owner, Up/Down graded to a Classic Tractor!

I have a 2nd battery in the right rear side. ______________________________
Vogue tdv8 08MY poverty pack - wow

It's an optima yellow top. ______________________________
Vogue tdv8 08MY poverty pack - wow

What extra electronics have you installed that should effect the drain that much that starting is now a problem?
With engine off the load should minimal, ideally less than 50mA, any more than that then you risk increased battery drainage issues and battery aging.
Fitting a larger starting battery is not the ideal solution as a standard starting battery is designed for starting and not for a continuous drain. For that you would need a leisure battery. If the load/drain is large enough then you might consider a split charge system with a leisure battery in the boot/trunk what would switch between the two depending on the situation.

OK, I did this on a L322 and there are some things to watch out for. I won't ask about your electronics - I'll assume your knowledge about wiring them correctly is up to scratch.

So, point 1. Don't mix battery types, not even on a split charge system. Different technologies will work against each other as I discovered. So, if you leave the main battery as Lead/Acid flooded wet cell then the one you put in the trunk must match, i.e. don't use an AGM one.

If you must have an AGM (absorbed glass mat) in the trunk then you need to fit the same technology up front. The list above for AGM contains the 2 batteries I used. A 020 up front with 105 amp hours and then a smaller one in the trunk. This allowed me to use the existing 100a cable to connect the 2 together via a 300 amp relay. This relay was fired from a fuse which only goes live with the engine running. I also fitted a bypass switch to fire this relay in case I needed to self-jump from the rear battery.

So, mixing technoligies and why not to do it. The 2 main types have different charging requirements and (more important) they behave differently when at rest. AGM will exhibit a higher rest voltage than wet cell so it will begin discharging itself to try and bring the wet cell up to its voltage. Then when it drops below the voltage of the wet cell the same thing happens in reverse - kind of a flip-flop constant discharge cycle. What I found was that the AGM never got up to full charge, the wet cell one was holding it back. The later cars had an intelligent (?) charging system which stops the alternator charging once the main battery is fully charged. The fact the AGM one was only at about 80% means nothing.

The one I used up front
https://www.tayna.co.uk/H15-Varta-Start-St...P8824.html

and in the rear
https://www.tayna.co.uk/E39-Varta-Start-St...P4367.html