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Discussion Starter · #4 ·
I bought the car second hand a month or two ago so I'm not sure. I doubt whether its a new battery though. I have disconnected and charged it to try and see if it resolves the issue but the message does come back after about a week.

I've read in some other threads that batteries on the way out will start throwing errors like these. The replacement battery is almost $500 (Aussie dollar)
 

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Hope your idea of disconnecting and fully charging the battery works; sure would not like you to have to spend $500 on a new one.
 

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Your car, assuming its has the i ELOOP system as shown in the picture, requires a special battery. There are also procedures for disconnecting, removal and charging that need to be followed to prevent issues. The Q85 battery isn't the same as a normal car battery. You can't just slap in an equivalent battery from Autozone, there aren't any. Check your battery to see if it is actually correct for the i ELOOP system.
 

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I have that Q85 battery but my UK car only has i-Stop, not i-Loop. You can get these batteries for around £100 in the UK if you shop around. I usually turn off i-Stop when I start the car partly because I I don't need it and party to preserve the life of these expensive batteries.
 

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Discussion Starter · #13 ·
There are also procedures for disconnecting, removal and charging that need to be followed to prevent issues.
Thanks for mentioning this. I went and looked for the official procedure and found this: https://euroesi.mazda.co.jp/esicont/eu_eng/mazda3/20110724140058/html/id0117h5800900.html

Turns out my battery reads between 12.3V and 12.45V so it is below the specifications of the car. Seems like the requirement is to be between 12.5 V to 12.7 V.

I will follow their charge procedure and report back over the weekend.
 

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Your car, assuming its has the i ELOOP system as shown in the picture, requires a special battery. ... The Q85 battery isn't the same as a normal car battery. ...You can't just slap in an equivalent battery from Autozone, there aren't any.
This is wrong. You can't use a standard starting battery, but you can replace it with an AGM deep-cycle battery, because the Q85 battery is nothing more than an "enhanced flooded" lead-acid battery for deep-cycle applications. These batteries are now common in decent parts stores. One brand is "Optima" (specifically, their yellow-top line); also Bosch makes a line of AGM batteries. These things are common because lots of cars now have start-stop systems or systems like the i-eLoop. They aren't cheap, though: expect to spend $150-200.

TL; DR: go to Autozone and buy an Optima Yellow-Top.

Lastly, you can try to preserve your OEM battery for a while longer: clean off the top, then carefully open each cell and check the water level. The water may be low. Carefully add *distilled* water if necessary. I used a syringe to do it accurately in mine: one of the cells was noticeably low, a couple others were just a bit low.

Also, while you can buy actual "Q85" batteries in Australia, the more generic AGM batteries like Optima Yellow-Top and Bosch are superior, and much cheaper. The Q85 is still just an "enhanced" flooded lead-acid battery, and horrendously overpriced; AGM is a superior technology. See this company's blurb about the applications for AGM.
 

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Discussion Starter · #18 ·
This battery is on the way out... After charging last weekend the warning light came back on yesterday. Voltage dropped again.

Do we have to use a Q85 or can we replace with a cold crank equivalent?

Sent from my MHA-L09 using Tapatalk
 

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Your car, assuming its has the i ELOOP system as shown in the picture, requires a special battery. There are also procedures for disconnecting, removal and charging that need to be followed to prevent issues. The Q85 battery isn't the same as a normal car battery. You can't just slap in an equivalent battery from Autozone, there aren't any. Check your battery to see if it is actually correct for the i ELOOP system.
I am trying to look out for this info. to me, the iELOOP is a separate system that generate energy to recharge the battery. Do you know the construction of this battery? batteries are batteries other than voltange and capacity. whatever added is outside the battery from my understanding of battery.
 

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Do we have to use a Q85 or can we replace with a cold crank equivalent?
No, you can't replace it with a standard starting battery, however you can replace it with a deep-cycle AGM battery that you can get at any decent parts store. They're a lot more expensive than a starting battery, but they should be much less than a Q85. Q85s are just "enhanced flooded lead-acid" batteries; AGM batteries are even better.


I am trying to look out for this info. to me, the iELOOP is a separate system that generate energy to recharge the battery. Do you know the construction of this battery? batteries are batteries other than voltange and capacity. whatever added is outside the battery from my understanding of battery.
The Q85 is an "enhanced flooded" battery. Here's some links about them:
What you need to know about EFB’s (Enhanced Flooded Batteries)
Enhanced Flooded Batteries | Johnson Controls

The short answer to all this is: just get an AGM battery from your parts store to replace your Q85 when it goes bad. Optima Yellow-top and Bosch AGM should work fine. Expect to spend about $200 in the US. AGM batteries are better than EFBs by every account I've read; the automakers use EFBs like the Q85 only because it's cheaper than an AGM battery (and then they can charge you a fortune for an OEM replacement).
 
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