I replaced the battery in my 2011 G5 Deluxe today.
Over the last couple of months, the one I had in it was getting to the point where it wouldn't hold a charge so I dug out my records to see how long it had been installed.
Would you believe I installed it 7 years ago? Yup. 2013 was when I bought it.
I figured if it lasted that long it might be a good idea to get another one just like it, even if it does have a rather odd name. It's a "Big Crank" AGM battery and I got it from Battery Mart so I looked them up on the web and sure enough, they still carry them. The price is a bit high at $89 but I figured it might be a good idea to get a battery that can last for 7 years at a high price instead of buying something for $49 and having it die in a year.
Anyway, the "Big Crank" battery that fits my G5 (the American name for a Electra) is a ETX-15.
Looking at the side of it where you can see both terminals, the positive (+) is on the left and the negative (-) is on the right.
I think a lot of the more common RE 500 UCE's like the C5 have the polls reversed with the (-) on the left and the (+) on the right. If your wanting to buy one of these batteries and you need the polarity of the terminals with the (+) on the right the number for the battery is ETX-15L.
I ordered the battery on Monday at about 10:00 AM Phoenix time and it arrived at my house at at about 10 AM on Wednesday. That's pretty fast for something that was shipped from Winchester, Virginia.
Remembering that brand new batteries usually need a couple of hours on a low amprage charger I tested the voltage as it was received. It was right at 12.8 volts. No charge needed with this one.
Anyway, here's hoping this Big Crank lasts as long as the last one did.