Mazda 6 Tourer - Battery Charging in Situ with i-Eloop - moward

Hi folks, looking for a bit of advice with regards to charging my Mazda 6 battery. With working from home now almost entirely full time, my annual mileage has plummeted to such that I am only half way through my third tank of fuel this year. Naturally this has not been entirely optimal with keeping the battery in tip top shape.

To date I have had to remove the battery from the car once the start stop system stops working (this apparently happens once the battery drops below 65% charge) and charging it with my CTEK CT5 battery charger. Replacement Q85 batteries are expensive and I don’t much fancy having to replace one because it got damaged by being discharged too much.

The CT5 charger came with a set of pigtail leads with eyelets that could be connected up across the battery to allow for quick connection to the charger and for trickle charging/keeping topped up without having to disconnect it. However I have not been able to successfully charge the battery in situ using these pigtail leads. It does however charge perfectly fine out of the car on my garage floor.

Ultimately my query is, for a Mazda 6 with the 2.0 Skyactiv petrol engine and with the i-ELOOP charging system, is it possible to charge the battery fully using the pigtail connector without having to disconnect it from the vehicle? There’s a current/voltage sensor connected to the negative terminal, should this be unplugged when charging in situ?

Many thanks in advance for any help provided.

Regards,

M

Mazda 6 Tourer - Battery Charging in Situ with i-Eloop - Falkirk Bairn

Car sitting around not being used = depleted battery

What to do.

Put a few gallons of Premium Petrol and give the decent car a run.

It's not just the battery that fails with sitting around - AC seals perish, tyres get flat spots, oil drains away in the engine ................ when the car is properly warmed up give the car an Italian Tune Up.

Repeat every 2 weeks unless you have actually used the car on a decent run.

Mazda 6 Tourer - Battery Charging in Situ with i-Eloop - elekie&a/c doctor
Can’t see any reason why your charger shouldn’t charge through the pigtail leads . Are you sure they are connected to the correct points on the battery terminals ? Do this leads have an in-line fuse ?
Mazda 6 Tourer - Battery Charging in Situ with i-Eloop - moward

I had connected the positive loop directly to the positive terminal on the battery and the negative to the chassis, similar to how its shown in the manual for jump starting. I don't think there's any inline fuses either in the lead nothing obvious to me . This is the lead in question:

CONNECT EYELET M6 CTEK Consumer

I know Mazda's i-ELOOP equipped cars have an oversized alternator and a large capacitor for quickly storing up charge on the overrun and under braking, which then releases it back into the battery over time. I'm not sure how the battery, capacitor and the remainder of the charging gubbins are all linked together but I'm wondering if the charger is picking up residual voltages from elsewhere in the system and then switching over to its maintenance mode too early.

Mazda 6 Tourer - Battery Charging in Situ with i-Eloop - Engineer Andy

Car sitting around not being used = depleted battery

What to do.

Put a few gallons of Premium Petrol and give the decent car a run.

It's not just the battery that fails with sitting around - AC seals perish, tyres get flat spots, oil drains away in the engine ................ when the car is properly warmed up give the car an Italian Tune Up.

Repeat every 2 weeks unless you have actually used the car on a decent run.

That's what I do with my Mazda3, though mine is pre-iStop and it's just to keep the ordinary battery topped up, fluids circulating, brakes un-seized and the A/C refrigerant not leaking and parts nicely lubricated, plus keeping the tyres in good order.

I just go two towns over (13 miles each way) for grocery shopping every 1-3 weeks depending on the outside average temperature/conditions - the colder/damper it is, the more often I do this (at most once a week, which seems enough). One a month or two for (on the way back as the car is fulled warmed up) an Italian tune up.

Been doing this for a good few years now. Seems to do the job, even if my battery 'only' lasts 4-5 years (not the end of the world).

Mazda 6 Tourer - Battery Charging in Situ with i-Eloop - Big John

Ultimately my query is, for a Mazda 6 with the 2.0 Skyactiv petrol engine and with the i-ELOOP charging system, is it possible to charge the battery fully using the pigtail connector without having to disconnect it from the vehicle? There’s a current/voltage sensor connected to the negative terminal, should this be unplugged when charging in situ?

I thought you couldn't charge the battery on an i-ELOOP Mazda with a standard battery charger as it will do expensive damage. Possibly as you've used a better charger it's detected the huge capacitor etc and backed off. I seem to remember there was a HJ article/report about this where damage had been done to the car.

I think the Q85 battery is something like an EFB - not quite as expensive these days. Myself I'd replace the battery to avoid expensive damage to the complex i-ELOOP capacitor/control gubbins.

The EFB battery on my Skoda Superb was showing signs of decay after lockdown/ working from home etc - Low voltage messages etc. Even after a run (when we could!) the message was back after a couple of days. Battery replaced and all has been well since.

Edited by Big John on 12/09/2021 at 21:38

Mazda 6 Tourer - Battery Charging in Situ with i-Eloop - moward

The battery charges perfectly outside the vehicle, I suspect its something else in the charging system that's throwing it off, probably some residual charge from the capacitor that the charger is picking up on.

The Q85 battery is an EFB, there doesn't seem to be anything particularly special or remarkable about it, apart from its weight.

I've spotted Yuasa do a direct replacement for about £160 but I don't think I'm at that stage yet. Its the lack of use that's allowing the draindowns for now but I try keep on top of it and charge up again when necessary.

If you are able to find that article, Id be very interested in having a read. I'm aware of Mazda's "special" procedure for charging batteries and I think its a bit of over egging the pudding tbh. The battery when charging on my garage floor doesn't even get warm, let alone needing a water bath to sit in.

Edit: after a charge, all is fine for a few months until the stop/start goes off again which leads me to thinks its just low usage at present with the associated draindown rather than a dud battery

Edited by moward on 12/09/2021 at 21:46

Mazda 6 Tourer - Battery Charging in Situ with i-Eloop - Big John

I've spotted Yuasa do a direct replacement for about £160

If you are able to find that article, Id be very interested in having a read. I

I got a Yuasa replacement for my Superb as it happens!

Article:-

www.telegraph.co.uk/cars/advice/honest-john-will-n.../

"You don’t say if you disconnected the battery before charging it. If you did not, then, with this type of battery charger, you will have damaged the system, in particular the i-ELOOP capacitor that temporarily stores regenerated energy for the headlights etc. I think you need to get the car fixed."

Edited by Big John on 12/09/2021 at 21:50

Mazda 6 Tourer - Battery Charging in Situ with i-Eloop - elekie&a/c doctor
Another possibility is to disconnect just the earth lead , and charge the battery using the vacated negative post using a croc clip . That way the battery is totally isolated from the car .
Mazda 6 Tourer - Battery Charging in Situ with i-Eloop - moward

I think this ultimately might be the only way forward whilst leaving the battery in situ. The battery is particularly heavy and I don't want to accidentally drop it on something whilst leaned over the bonnet, and definitely not on my foot whilst carrying it.

Been reading up a bit on how it works at the following link, looks like there's a bit too much going on in this system for the charger to be able to isolate the voltage from the battery only whilst its still connected to the car.

i-ELOOP [i-ELOOP] (nema.club)

According to this if i understand it correctly, the capacitor actually only dumps its charge back into the battery after the ignition is turned off. One could be driving about all day long and not charge the battery at all until its turned off at the end. I have noticed this before when the stop start doesn't work driving to the shops, yet comes back to life when I get back into it for the return journey. I really wish this sort of info was published in the manual, would save me a lot of confusion.

Mazda 6 Tourer - Battery Charging in Situ with i-Eloop - Engineer Andy

From what I hear - rather like with traditional hybrid cars, these systems hate doing short journeys from cold. They need time for the main battery to recharge and only then will they charge the secondary system.

That's why I personally think it's daft to have such systems (plug-in hybrids and EVs are obviously less affected) in small city/shopping cars - like with this situation, they just end up as dead weight and cost a small fortune to replace if required.

The problem is that due to current-day circumstances, many people have either been forced into or now prefer to work from home, but their cars weren't designed to just sit around doing nothing for so long.

 

Value my car