Are you still happy with your RedTop? I am planning to pick one up from O'Reilly's tomorrow morning.
It's a
very solid, decent battery. Above-average CCA (for the Group 35 category). Though it's aH output is middling and reserve capacity is below 100mins. Still, a very reliable unit. Have used this RedTop 35 in temps from -10ºF to nearly 110ºF.
Over the past three vehicles I've owned, they've all had Optima YellowTop or RedTop batteries. Have only once had one fail, and that was a couple years past "warranty" end-of-life (hence my 5yr replacement tendency). I generally replace after 5yrs, simply out of dislike for getting stranded.
By next year, it's battery swap time again. Which is why I'm mulling slightly-larger sizes. To get much greater reserve, higher CCA. Don't much like the idea of cutting the tray or ending up with a kludge setup, but if it fits well enough and is safely in-place ...
FACTORY = GROUP 35 -- ~ 9.4"L x 6.8"W x 7.7"H
Possible batteries next time around ...
Optima Redtop 35 -- 720 CCA, 44 aH, 90min reserve; 9.4"L x 6.8"W x 7.7"H; have had this one in the current Mazda CX-5.
Optima Yellowtop D35 -- 620 CCA, 48 aH, 100min reserve; 9.4"L x 6.8"W x 7.7"H; have used this one in a previous Mazda Miata.
Optima Redtop 34 -- 800 CCA, 50 aH, 100min reserve; 10.1"L x 6.9"W x 7.9"H.
Optima Yellowtop D34 -- 750 CCA, 55 aH, 120min reserve; 10.1"L x 6.9"W x 7.9"H.
XS Power D2400 AGM 24 -- 1056 CCA, 96 aH, 186min reserve, 3yr warr; 10.3"L x 6.7"W x 8.4"H.
XS Power D3400 AGM 34 -- 1012 CCA, 80 aH, 160min reserve, 3yr warr; 10.3"L x 6.9"W x 7.2"H.
XS Power D3478 AGM 78 -- 1012 CCA, 80 aH, 160min reserve, 3yr warr; 10.3"L x 6.9"W x 7.2"H.
Then, there are some seriously over-sized "pigs" in the running, which would require some judicious snipping, adjustments, anchoring. Still mulling over measurements, adjustments required. But probably these are all too large.
XS Power D4800 AGM 48 -- 836 CCA, 72 aH, 132min reserve, 3yr warr; 11"L x 7"W x 7.5"H.
Optima Yellowtop DH6 -- 800 CCA, 72 aH, 140min reserve; 11"L x 7"W x 7.5"H.
XS Power D2700 AGM 27 -- 1144 CCA, 113 aH, 239min reserve, 3yr warr; 12.1"L x 6.7"W x 8.4"H.
Optima Yellowtop DH7 -- 880 CCA, 80 aH, 155min reserve; 12.5"L x 7"W x 7.5"H.
XS Power D3100 AGM 31 -- 1376 CCA, 127 aH, 273min reserve, 3yr warr; 13"L x 6.9"W x 8.5"H.
NorthStar X2Power AGM 31M-- 1150cca, 100Ah, deep cycle marine; 13"H x 7"W x 9.3"H.