Battery chargers

Plenty of basic chargers under £50. I don't recall seeing AH limits on ones meant for cars.

For a little bit more, I've been very pleased with this:

On the "normal" setting it will often get a big diesel car or van going in ten or 20 minutes, assuming the battery has not been completely flattened.

And the boost setting will normally get smaller engines started straight away, as long as you can get a good connection with the clamps.

These are usually smart battery chargers, for he latest all singing all dancing make you a mug of tea in the morning batteries

Most cars these days charge the battery while they are being driven about, so you don't need a separate charger.

Further, they use alternators which generate useful currents at low speeds, so your battery recharges even when the engine is at tickover.

Why do you want a separate charger?

If you want one that can be left connected for long periods, or even run off a timer, without damage being caused by overcharging, then one of the very best is the C-tek. Second best is one of the cheapies from aldi or lidl, but they will not re-start charging if the power goes off. Ring make a very good range which will also resuscitate a mildly sulphated battery, show you the voltage or amperage or state of charge. Depends on your actual needs and budget which will be best. As even a mid range battery is 50 quid and many are around the hundred, if your car is not in regular use then a charger can save you a wrecked battery and will repay the outlay.

When you find one that works let us know.

Aldi ones only show charging volts.

My "smart meter" from Aldi won't even begin on a properly pancaked battery. Won't put any juice in so you can't get the car to the new battery shop. I have had to get the 30 year old crude transformer and plate diode 4 amp one out from under the stairs before now.

Agreed. All (?) the smart type ones need some voltage already in the battery in order to detect polarity and start to do something. Any 12 volt wallwart will do to get the process started.

The Ring chargers show volts, amps and condition, screwfix sell one or two.

:-) Probably a new battery would be a better idea.

I have a cheap, ALDI bought charger in case of the odd occasion when I may leave lights on (difficult to do in modern cars), but mine has mostly been used to rescue neighbours who have dying batteries.

How quickly do you need to re-charge a battery?

If overnight is ok, a Lidl/Aldi smart one at under 15 quid is ideal. Although it is only about 4 amps, it delivers all of that until the battery is charged, so much quicker than some others which claim a higher output. For example my Halfords one which says 11 amps on it. Yet the Lidl one charges to full in a shorter time. And is also a fraction of the size

- it will fit in a (large) pocket.

Just for guidance it will charge my 70 amp.hr battery overnight, and can safely be left on for ever, as it switches to a maintenance charge when the battery is full.

Lidl tend to have them on offer several times a year.

or a replacement. Choices seem raher complicated today. I just want one tha t will tell me what amps are going in, whether I've connected the leads cor rectly and not cost a lot - say up to £50.

h. Why this limit? My previous chargers have never stated any limit.

urns out to be the best of the bunch. It's an Autocharge10.

I have a range of batteries on different vehicles and often they are not be ing driven much, so need a charge. Particularloy does a go-cart I made for my grandson using a Chinese scooter engine and transmission.

Well, in the end I went for a Maypole 716. Why? Because it was one of the o nly ones that looked the part ('strange reason' do I hear from the back?), had a proper ammeter, appeared to be able to charge most car batteries, cos t £41.59. But obviouisly it hasn't had a lot of use yet so I'll have to w ait and see how good a buy it was. Biggest problem? It wasn't a recommendat ion from Mr Cheerful, in whom I have the greatest faith.

Fair comment.

Essentially you are only trying to combat the loss of charge over time - so a small solar panel (about a square foot) connected to each battery when the vehicle is parked could be a good solution. No need then to find the charger a few hours before you intend to use the vehicle - it will be virtually fully charged whenever you need it.

Your only real problem with an old type charger is the need to keep an eye on it and not leave it charging too long (especially little batteries) Plug it in with a time switch if you are apt to forget/go out. The modern type smart ones will turn down to a rate suitable for continual charging and will cause equalisation of cell voltages (a good thing) and some (like the Ring ones) can even cure light sulpahation. I hope it works well for you. Not certain if it should be used on some of the modern AGM or gell batteries, but they are still rare in the car world.

Looked at the spec of the Maypole, and it wasn't very helpful. The quoted peak output is pretty meaningless - it's how well it regulates the charging current during charging which matters more. Many will start out at a highish current but very quickly drop to a lower one and taper off as the battery charges. Which means they can take longer to charge a battery in practice than a lower peak output 'smart' one.

Also can't see the point in paying for an ammeter. Tells you nothing - other than the charger is working. An LED can do that.

Also by the size looks like it contains a transformer. Silly these days as a SMPS is smaller, lighter, cheaper and more efficient.

Not very practical for overnight charging when it's needed most though.

Neighbour had one of those on a little used Porsche. Didn't seem to cope with the losses from alarm etc. Notice it's no longer there. Might have worked if we got sun all day, of course.

You should read the 8 pages on battery condition and charging in the Nissan service manual.

Initial rate should be set according to initial specific gravity and battery capacity. That demands a charger that has adjustable output current and a meter.

The average person does not have any need for the technical details of battery tech. and charging, which is why the smart chargers are a very good bet for almost everyone.

I'm sure they do. Lots of car makers do this sort of theoretical stuff - straight from some ancient textbook.

And do you really see a Nissan main dealer going to this effort just to charge a battery? And it likely only applies to fast charging. Such a charger costs hundreds. Not a DIY device.

I use a stabilised 12 Volt power supply to keep my camping batteries float charged. The current drops itself off as the volts come up. Gets it up to 80%. I have another variable power supply which I set at 13V if I want to charge it right up to the limit. Again the current drops itself off so overcharging can't happen.