I have a LiFePO4 battery in my Miata. It is not suitable for use in a daily driver in a vehicle with a high power demand like a CX-5. It has enormous starting power (current), but has relatively little capacity, measured in Amp-Hours. Specifically, the battery I run weighs 4.8 pounds, has 540 CCA, but only 12 A-Hr compared to the OEM battery's 45 A-Hr. I am on my second one partly due to sitting at a burger drive-in listening to the R&R Hall of Fame awards for 45 min. Battery died. I forgot and left a door open in my garage a few hours another time and it dropped so low it would never recover. 13 A-Hrs, doesn't go far. To keep the dark current from pulling the battery too low (takes 2 weeks, sitting) I have to keep My Miata on a specialty charger when parked.
In addition, I cannot run my blower fan on max if I will have to idle the engine, because the Miata's charging system drops below 13.1V in that situation. That will cause damage to this LiFePO4 battery.
All this is fine with a toy convertible, or specialty application like a motorcycle that we all like to fuss over, but, every day? No.
As heavy as a CX-5 is, there is no point. Losing 27 pounds in a 2500 pound car, maybe. I thought the steering responded a little quicker. Dropping 34 pounds in a 3600 pound SUV and paying $300 to do it makes little sense.
An AGM battery will last longer for a small premium, if you are dying to blow cash. Flooded cell Pb-SO4 batteries are the most popular car battery for many reasons.
Thanks Colt... it's great to hear from a miata owner that's run these before. Needed this real world opinion. Your post helped me decide to stay away from Li for now. Lithium seems like it still needs to work out alot of problems and lower pricing.
For now a lightweight AGM is the way to go, even though pricier. If I wasn't adding weight to a non-turbo, would just use my $120 Napa lead battery(37 lbs).
The Mazda CX5 non-turbo setup and curb weight seems close to perfect and has just the right amount of pep...in retrospect shoulda got the turbo(but only because I'm adding weight.)
However in order to maintain close to stock weight, while adding accessories, means need to drop some weight, wherever I can, including the dreaded gym membership.
Don't want the cx5 to feel sluggish after adding 100 to 150 pounds of modifications and additions( hitches, roof racks, fullsize spare, etc.) on the daily driver to only feel more sluggish once start adding passengers and luggage, etc. on vacations, wknd excursions, etc.
For most people reading this thread, it appears a cheap flooded lead acid should be just fine(I prefer NAPA). However, for those adding a ton of weight, a lightweight AGM seems preferable over a lithium.
For reference, the Mazda cx5 stock battery = approx. 32 lbs. ( Which is decent), flooded lead acids and regular AGMs are between 30 to 50 lbs, lightweight AGM are 16 to 21 lbs, and Lithium are 2 to 16 lbs. Pricing wise, Flooded =$, AGM= $$, and Li = $$$.
On curb-weight, it's interesting to see Ford pushing towards 4 cylinder vehicles like Bronco and Maverick with approx. same curb weight as the cx5 to gain fuel mpg, while Mazda is going in other direction with plans to throw 6 cylinders in the new cx5s. Why can't the manufacturers just make a inline 5 SUV? For the perfect balance?
Thanks again for sharing your knowledge / experience.