I have a 2018 CX5 Grand Touring and need a new battery.
Does anyone know if a CX9 battery will fit ?
Also, any suggestions for a good battery and a good place to get one ?

Thank you in advance,
Robert

 

I have been happy with O-Reilly Auto batteries. I would assume a CX9 battery would fit as they use the same 2.5T motor as the CX-5. Not sure if the non turbo 2.5 uses the same battery but I would think so. Most batteries come out the same couple of plants anyway. Just decide if you want an AGM or not.

 

Why would the OP ask to use a CX-9 battery? Depending on the year and model, both use a Group 35 battery with a minimum of 550 CCA.


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I usually get my auto batteries at Costco and they didnt carry one for a CX5 after 2016. However, they have one for the CX9.
I did some research and the CX9 battery is very similar.
In fact I called the dealer and spoke to the parts dept. They said they sell the same battery for the CX9 as they do the CX5.
So after doing research I went to Costco and for $89.99 I got their Interstate battery for the CX9 and it fit perfectly into my CX5.
The cranking Amps etc were the same too.
So far so good !

What I found interesting though was with the old battery I got a lot of codes.
When I would start the car I would get a check engine code or a smart brake system failure.
The craziest part is the power rear liftgate stopped working. When I put the new battery in, it worked again.
So if your battery is getting weak its better to replace it as soon as possible so you dont get any codes and dont do any damage to the vehicle.

 

This is typical for most all modern vehicles. As a battery nears its death the voltage it actually supplies to the vehicle drops. With all the computers in modern vehicles a small drop in voltage can cause a malfunction and trigger a code. The vehicle may still start, but it can’t keep every electronic system functioning correctly.

 

May I offer this fairly universal guide?
A basic electric meter (VOM, for example) is all that's needed.

Check voltage 4-12 hours after shut down:
12.8v = new battery
12.5v = 3 year old battery
12.3v = seek replacement
12.2v = FAILED battery

With many people driving less, battery pros suggest overnight charging (using a suitable charger) every 60 days.
Remember, the AGM batteries are happiest with an AGM tailored charger. Old fashioned, basic chargers kill AGM's as they near full charge.
'Tis always better to change a battery early than allow it to strand you.

 

Interstate is a respected brand, you did good on the price.

 

Thank you Robert for the information. I had/have the same issue. Went to Costco yesterday and no battery for our 2018 CX5GT. I will go today and ask for the CX9. Do you know if this what they are calling the group 35 battery?

 

Yes, 35 according to Costco's battery for the 2018 CX-9. Still find it odd the CX-5 isn't listed..

https://costco.interstatebatteries.c...898&Country=US

 

On my own 2016 CX-5, I just installed an Optima Red Top. It's a Group-35 battery. (On the CX-5 it required use of the included plastic platform, to be high enough for the tie-down bracket to hold it in place.) And it was listed as the fitment for the CX-5 and CX-9, both for the 2016 and the OP's 2018. More expensive than the Costco one, of course, but O'Reilly Auto Parts' search lists various batteries as fitting both vehicles, and both vintages. So, other than minor size differences from make to make of battery, it should fit.