I have just received a CTEK 3.8 battery charger to top up and maintain the battery on my 58 Reg 2.0L Sport. The car only gets used on sunny dry days (remember those?) so it is getting a bit sluggish when I want to start it. I have a couple of questions about the charging, 1. Do I need to remove the cell caps during charging? The battery has lifting straps and it’s probably an original fit and I have read all sorts of conflicting information. 2. Is it best to connect the negative charger clamp to the battery terminal or somewhere on the block/chassis. Thanks
Negative can be connected to the battery post or chassis that is connected to that post via clamped lead, so whatever is more convenient to you.
If you have a battery with caps, I would remove them and charge the battery off the car with a normal charger but leave them in place with a trickle/maintenance charger.
Make sure that the CTEK will work on yours. My Panasonic is 31 amp which is just about OK for use with my optimate 3, designed for motorbike batteries.
Hopefully you have an AGM(absorbed glass mat) battery rather than lead acid - they respond far better to trickle chargers and prolonged periods of non use.
NC has a conventional lead acid battery.
I’ve currently got mine on a trickle charge, mine is the Lidl charger, rather much like the C-tek I believe. I just loosen the caps on the the battery, just to be safe. They seem to have breather holes in the caps anyway. I don’t leave mine on charge 24/7 although no harm will be done in doing so. What I find now is, my battery is getting to the stage where a replacement maybe imminent, as after a charge up over a couple of days it’s becoming apparant it loses charge faster now, but still starts the car ok ish. It is coming up to 8 years old, an original.
I have a 59 plate 2.0 Sport Tech. If I am not driving it is connected to my Ctek 3.8 charger and I have never removed or loosened the cell caps. It always starts instantly and I have never had any problems with it. I use the plug in connector lead which is permanently connected to the battery.
Kev.
The car’s alternator charges the battery while driving and nobody suggests removing the cell caps then. Where does this strange idea come from?
Guess it goes back to the good old days (or maybe not) when battery charging you did these sort of things. I remember putting many a battery on charge and they used to bubble away, always said remove the caps before charging. Yep, things have moved on, you can hardly notice any charge taking place now in a battery such is it’s low charge rate. I am sort of stuck in my ways, thinking the thing is going to go pop.
Now you’re going to tell me you are over 60 yrs old and have never done this.
When charging the battery off the car, the workshop manual does state to remove the vent caps and in some instances it says to place tbe battery in a water bath too.
My other toy has been on a battery conditioner 24/7 from end October to beginning of April for the last 14 years. Never taken any caps off and my first battery lasted 12 years
Thanks for all of the comments, I have enjoyed reading them. I think my problem is that the last time I charged a battery was on a Mini in about 1964. Things seem to have moved on since then although in the MX5 owner’s manual it does say undo the cell caps. I thought that was a bit strange because what would be the point of the CTEK comfort connector if you still had to remove the battery cover and the cell caps. Thanks again, It is now on charge.
Those were the days
The old fashioned unregulated chargers. Mine finally blew up, luckily!, whilst I was charging up a neighbours battery. I didn’t realise that there was a short in the battery and it started to rain, so put the charger and extension lead in a dustbin. Next morning I found one very burnt out charger in warm, smelly bin - it could easily have set fire to the bin which was quite close to neighbours house.
Never needed to put a battery in a bath of water but you can’t criticise over cautious advice. If you do use an old style unregulated charger, particularly on HI setting, always leave the caps loosely over their ports - stops the bubbling acid spitting out!
Smart chargers are the way to go but mine will not cope where voltage has dropped below about 10V, so a quick boost needed with an unsophisticated charger first.
A modern battery with a car in daily use should maintain charge and as soon as the battery struggles, charging largely as waste of time as battery has reached the end of its life.
Voltage retention at around 12.7 volts(little less for Panasonic) after charging is a reasonable method of checking a batteries health
I know why people are concerned about removing the cell caps. I was once in a back street garage and they had a truck battery charging on one of those huge rapid chargers. Without warning, the battery exploded, showering the whole unit in bits of plastic and acid. It was pretty frightening.
However, no domestic charger has the power of these commercial units, and most batteries are vented these days anyway. I have been merrily charging batteries at home for 30+ years, and I don’t think I have removed the caps for the last 20 of those - or put the battery in a tray of water, either. If a battery is ‘maintenance-free’. then getting the caps off will be a struggle anyway, a clear indication that it isn’t necessary.
I would always attach the charger to the battery terminals, so that the battery gets the full whack of the charger (there may be a small voltage drop between battery and earth point). The advice to put the negative to a chassis or engine earth is mainly for jump starting, where the battery may be gassing heavily and a stray spark could blow it up. As long as you switch the charger off before removing the clips, there is no risk of a spark.
Assuming the Ctek and Aldi/Lidl chargers are similar to my Optimate 3, they will provide a short boost charge at the start of the charging sequence if the battery voltage is low, and they will also provide a float charge when the battery is fully charged, which can be left on indefinitely. A lot of motorcyclists (well, the weedy ones who garage their bikes over winter) put an Optimate on in October and take it off in April, and no harm done, just a nice fully charged battery for the Spring.
Optimates can also revive batteries which are apparently dead, although you may need to leave it on for a full week for the magic to work.
Yep - I’m one of those wimpy fair weather bikers, although tempted to get out this month rather than the usual March.
Optimate 3 is still well thought of - mine has been doing a great job for years.
Not sure if yours is different to mine but the charging simply fails with the appropriate red light when car battery voltage dropped too far.
It wasn’t a problem once I had worked the issue out as low voltage - simply use old style charger for a few hours to boost voltage and then reconnect to the smart charger - another revived Panasonic
Hi,
Has anyone thought about doing what I do and make your mx5 your every day car , there fore the battery never becomes an issue l. Can’t go flat if it’s normally on the road.
They are even more fun on the frosty roads.
Michael
Mine’s an Optimate 3, like yours. I had a battery in my mower die totally, no lights and not even a click from the starter solenoid. I put the Optimate on it and got the yellow light which I think indicates suplhation. Overnight it did nothing, but as I had the battery on the bench and I didn’t need the mower for a while, I left the Optimate plugged in. It took a week, or maybe 10 days, but eventually I got a green light, and the battery lasted another year or so in normal use afterwards. I was impressed.
I’ve got a c-tec battery conditioner and i have connected the extra leads that come with it permanently to the battery so now I only have to connect the charger to the connector each time which is simple and works fine.
Nice one Michael - you are totally correct. The bullet proof Panasonic, however, does saves fair weather drivers from the headache that normally results from this sort of treatment.
Zulu - glad you sorted out a totally flat battery with the optimate. I’ve never let any of my batteries go far enough to get to that stage - the battery I had with low voltage was on the MK2 I bought a couple of years ago. It may be that the charger is more flexible with the smaller batteries it was really designed for.
Mine does a test charge before either failing with red light or going into recovery charge mode. Failure happens fairly regularly, so I just restart the charger. Tried this several times without success on the low voltage MK2 battery.
Don’t be silly, it would get all that salt/grit on it and have run through all those unrepaired potholes.
Just think of all those repair bills, for the sake of buying a cheapo battery charger.
Hi Mick sorry but changing the subject ,I’m thinking of lowering my MX soon and I was wondering what springs you have fitted to your car as it looks about the height I want mine to be not too low. Cheers Martin.