[Willdu]

Hi, new member here, located in UK. I have had my CX60 since September. Mainly short local journeys in EV mode. Warning has appeared on dash telling me that the 12v battery is low, and to start the engine. I have done about 40 miles on engine only, but warning still appears with annoying sound that continues for 30 seconds. I connected a battery charger, and left it overnight, for two nights running. Warning still appearing. Help!

 

[Willdu]

I'm also suffering from this - I will try and59's solution.

I put a cigar lighter type voltmeter into the the socket and checked the voltages on the battery - Nothing wrong with the voltages - All within normal ranges.

Thanks for your reply. I have a 12v battery meter arriving today. I had it booked in at Mazda dealers, but then warnings stopped, so I cancelled. Now it is back!

 

[Willdu]

Thanks for your reply. I have a 12v battery meter arriving today. I had it booked in at Mazda dealers, but then warnings stopped, so I cancelled. Now it is back!

Checked the battery today, showing not fully charged. Ran the engine for a few minutes, meter then showed fully charged. Warning back on shutdown.

 

[Willdu]

Did you follow the suggestion from and59 - I've not had the warning since I started doing this.

What voltages did you get before and after?

I have seen suggestion from and59, I have done this with no success. My meter only has lights, fully charged one is flickering, but is steady after running the engine for a few minutes. Going back to dealer next week.

 

[Willdu]

I have the MyMazda app on my phone. Will try and show text that popped up. I have a voltmeter arriving tomorrow. Steve, just in general where in the country are you? Screenshot is below.

 

[Willdu]

I have the MyMazda app on my phone. Will try and show text that popped up. I have a voltmeter arriving tomorrow. Steve, just in general where in the country are you? Screenshot is below.

I am in Warwickshire. Maybe a stupid question, does the CX60 have an alternator? I heard somewhere that some PHEV's don't have them. How else would the engine charge the battery? Unfortunately, I don't profess to be a mechanic. Seems that Mazda batteries are at fault. Never had battery trouble with my CX5.

 

[Willdu]

Mine is going in next Tuesday, be interesting to see what they come up with. Can't see them changing faulty batteries for the next three years. Mine has done less than 1,000 miles.

 

[Willdu]

I went to the service center with this complaint and yesterday they called me and changed my 12v battery. Until now, the message has not appeared. It seems that the problem is solved.

This morning, reading on voltmeter was 13.5 with engine off. Engine running it is showing 14.2. Had a thought. When I bought the car, the salesman told me that they had halted production of the CX5 to concentrate on getting the CX60 to market, and they were using what parts they could. Maybe the CX60 has the wrong battery? Have now run the engine for 5 minutes, turned off and the reading is 12.8, less than before. No annoying warning though.

 

[Willdu]

On another forum, it has been suggested that problem is with the smaller backup battery, not the main battery. This was confirmed in a conversation with the service manager at my dealer.

The voltage measurements mentioned above only relate to the main battery.

Sorry, do you mean the battery that is located on the passenger side just underneath the windscreen? If so, that is the one I thought was the problem. When you say main battery, do you mean the one that actually drives the wheels!?

 

[Willdu]

The Cx60 has two 12v batteries, one small one as you mentioned and a normal AGM 12v battery.

The hybrid battery is 48v.

Thanks. Where is this AGM 12v located?

 

[Willdu]

There are, as far as I’ve learned 3 batteries.

A 48v battery for driving the wheels
A 60Ah 12v battery, located under the cover in the engine compartment, near side in a RHD model
A 6.3Ah 12v backup battery located somewhere accessible from inside the car. This is the one that’s apparently the problem.

That’s why measuring the main 12v battery shows good voltage and charging up doesn’t fix the problem.

Thanks, I will go hunting before Tuesday, when it goes in.

 

[Willdu]

I will. Of course the warning hasn't appeared today.

 

[Willdu]

Steve. I found something under the drivers seat, towards the front. Black plastic cover. Holes in part of it with what looks like a heat sink inside. Two button looking objects on it. Thought I could remove the cover somehow, but didn't want to damage anything. Possibly have to lever off the buttons maybe. Could this be the elusive battery?

 

[Willdu]

On another forum, it has been suggested that problem is with the smaller backup battery, not the main battery. This was confirmed in a conversation with the service manager at my dealer.

The voltage measurements mentioned above only relate to the main battery.

It gets more baffling. Spoke to the technician he says there are only 2 batteries fitted. The large drive one, and a normal 12v. If there is another one, it beats me where it could be. Attachment below on what they carried out. Any further problems they will have it for a couple of days.

 

[Willdu]

When did you get the battery changed and has it cured the problem permanently?

My CX60 is at the dealers for the second time with this problem....

I had my car in the dealers a few weeks ago. They didn't replace the battery, but reset various settings. No problems since.