Q85 battery replacement / I-stop.

Faults and Technical chat for the Mazda CX-3
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Re: Q85 battery replacement / I-stop.

Post by lhcmazda » Tue Jun 30, 2020 8:25 pm

I have a CTEK start / stop charger and just connect it to the battery without disconnecting the battery from the car, and not experienced any problems. The only thing I have noticed is that even though the battery is shown as fully charged, i.e. the charger is showing "Care" mode. When I access the cars Fuel Economy Monitor it doesn't always show a fully charged battery, i.e. a Blue Halo around the battery symbol, and the stop / start facility does not therefore work. However after a few runs the battery Blue halo appears and the stop / start function is restored. I have tried other chargers with the battery connected and experienced exactly the same conditions.

2018 Mazda CX-3 2.0ltr sports nav AWD Auto petrol.

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Re: Q85 battery replacement / I-stop.

Post by jtonline » Tue Jun 30, 2020 8:50 pm

Well health & safety & Mazda would say remove battery from the car before charging because highly explosive hydrogen gas is released during charging & could build up under the bonnet.

Disconnecting the negative terminal may be worthwhile to protect the vehicle’s electrical components from over voltage if a smart charger produces a high voltage during all or part of its cycle.

However, you’ll probably find loads of people that do neither of those things and everything’s been fine.

It’s important to check the electrolyte level in the battery & top up if necessary before charging, and leave the filler caps off during charging.

I have a 10A Ctek charger that I got during lockdown, just in case, but I haven’t had to use it yet.
09/15 CX-3 Sport Nav, Dynamic Blue Mica, 1.5 Diesel, AWD, Automatic
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Re: Q85 battery replacement / I-stop.

Post by Doug » Mon Jul 06, 2020 11:12 pm

With my 2016 CX3 I experienced the I-stop continually turning off permanently when the battery level dropped by a quarter to 3/4 charge. With my 2019 I pop it onto automatic charge when it is likely not to be used with in a 3 week period or more. On charge throughout lock down, no problems. There are 2 ways to reset the I-stop. Have Mazda do it with there computer reader or go through the long drawn out turn the method like an alarm setting up. Great if you have a key to turn!
June 2019, CX3 Takami , Soul red crystal metallic, Automatic 2WD 2Ltr petrol.

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