Aldi battery charger.

[Avulon]

Originally Posted by SD1too

When you think about it, what's the difference between the "voltage changes" caused by:

1. The ignition being turned on
2. The operation of the starter motor and
3. The alternator commencing charging

and a modern 'smart' battery charger?

Nothing I would suggest.

Simon

Except that the car battery can't provide more than 12.8v and teh alternator (as long as it's working properly) somewhere around 14.4v (Both DC)

A modern battery charger could supply full mains AC in a failure. Even a failing Regulator isn't going to supply more than 80v (and probably dirty DC)

Originally Posted by mss

A current surge by itself is not really the problem but reactances within the car can turn it into a voltage spike. This does happen.

Above battery voltage? I'm sorry, but I don't believe that Apart from the alternator there aren't any other large inductors or Capacitors in our Cars. Which you'd need in order to multiply voltage. What do you think happens in the ign switch...?

[MSS]

Originally Posted by Avulon

.............

A modern battery charger could supply full mains AC in a failure. Even a failing Regulator isn't going to supply more than 80v (and probably dirty DC)


.............

Hence my repeated focus on how a charger handles failure modes, including externally induced voltage transients and the quality of the protection components in the charger!

Originally Posted by Avulon

...................
Above battery voltage? I'm sorry, but I don't believe that Apart from the alternator there aren't any other large inductors or Capacitors in our Cars. Which you'd need in order to multiply voltage. What do you think happens in the ign switch...?

Really?

How about field winding on the starter motor, the coils in every other motor, all the relays and solenoids, and of course the multiple meters of wiring!

Then there are all the stabilising capacitors in the electronic modules.

Why do you believe that on this very forum a number of the gurus have said that they've had to deal with corrupt EEPROM data follwoing battery replacements? Please explain!

Also, please explain the spark on connection mentioned by member tourer above.

Don't forget that induced EMF = -N dPhi/dt = -LdI/dt which means that the amplitude of the induced transient (voltage spike) is proportional to the rate of change of current, not the size of the current. It takes very little energy from an induced transient to damage a CMOS circuit.

[COLVERT]

Originally Posted by mss

And guess how many of the cheap chargers do not have one! Also, if it does, can you trust it to act like a fuse?

Similarly, the cheap £2.89 DVM's. They are OK for simple tasks, but they are no Fluke 77!

Ditto cheap PC power supplies which are the closest item to a modern charger in terms of functionality. Many of them are dangerous!

Simple answer. Fit your own in-line fuse.--Cost a pound or less and fitted in two minutes. You won't then pass enough current to damage other parts of the cars electrical system.

[MSS]

Originally Posted by COLVERT

Simple answer. Fit your own in-line fuse.--Cost a pound or less and fitted in two minutes. You won't then pass enough current to damage other parts of the cars electrical system.

See my post immediately above

[COLVERT]

Originally Posted by SD1too

When you think about it, what's the difference between the "voltage changes" caused by:

1. The ignition being turned on
2. The operation of the starter motor and
3. The alternator commencing charging

and a modern 'smart' battery charger?

Nothing I would suggest.

Simon

I would guess it's the FREQUENCY of the changes in voltage. The chargers voltages would be hopping about all over the place.---

Lots of the car's electronic components would never get the chance to go into SLEEP mode.

[MSS]

Originally Posted by COLVERT

I would guess it's the FREQUENCY of the changes in voltage. The chargers voltages would be hopping about all over the place.---

Lots of the car's electronic components would never get the chance to go into SLEEP mode.

Why - please explain COLVERT.

[COLVERT]

Charging the battery on the car.--Just remove the negative lead to separate the car wiring system from the battery charger.

You can buy a 12 volt battery unit that plugs into the cigarette lighter to maintain 12 volts in the system with the main battery disconnected.

Avoids radio code loss and spikes induced into the cars electrics whilst connecting and disconnecting the battery.



High voltage sparks ( Spikes. ) are generated when a connection that has current flowing through it is disconnected.

As the connection is being broken an arc forms between the parts because the current tries to continue to flow.

This arcing is what generates the rise in voltage and the subsequent spike as it fails.----

Remember---disconnection, not connection.

[COLVERT]

Originally Posted by mss

Why - please explain COLVERT.

The Rovers electronic system goes slowly into sleep mode and, lets say, after half an hour is using the minimum current possible to be ready for when the system needs to be activated again.

Pressing the key button, opening a door or any other electrical use will make the electronics click into action.

A pulsing charger like these smart chargers will keep, in effect, prodding the system awake with the fluctuation voltages needed to trickle charge the battery.

[COLVERT]

Originally Posted by BigBen

The Alternator is not just a generator, it has rectifiers and regulators to prevent over-charging and spiking and will also blow in extreme cases to prevent possible damage (although, as we know, that doesn't always succeed!).

For me, there's a massive difference in maintenance charging or "conditioning" - i.e. charging the battery while in-situ in the vehicle - and re-charging from a flat or low charge state - i.e. removing the battery from the vehicle first.

But then, I have always removed any battery from the vehicle to charge it.

I have various chargers, including one bought from Argos @ £15.99 - It's an 8A smart charger that is also suitable for AGM & Gel batteries and works very well. In fact it's the one I use most often. I also have a battery conditioner I used to use for my bikes, but again would only use it with the battery out of the bike..... especially when it's an £80,000 race bike.

I don't see the point in risking the vehicles' electronics under any circumstances for the sake of the 2 minutes it takes to remove or re-install the battery.

If keeping the radio presets and clock time mean so much to you, then fine.... but my ECU's etc. mean far more to me!

Mr Ben Sir.

Possibly half the drivers on the roads today are women. Of the other half, men, most wouldn't know a battery if it bit them, let alone remove one from a car.--


However lots would actually be able to connect a battery charger to a battery by reading the instructions.

I would guess then that most batteries would be charged whilst still on the car. ( Better off than on, as you say. )

Two main risks.

1/ The battery might explode.

2/ Disconnecting the leads might cause a damaging spike to the cars electronics.

So there you have it. A choice.

My choice would be on the car. Personal experience over 65 years of motoring on the road with no problems.

Plus the fact that even with the correct tools I don't think I could get the battery of the car in the two minutes you mention.----

[marinabrian]

I'd be surprised if you could generate enough inductive reactance in any wound component or wiring of these cars to cause any mischief to the electronics.

EEprom spikes tend to occur when a car is connected to another for the purpose of "jump starting"

And what is the purpose of a fuse in a circuit? it is not to protect the appliance, but the cable to which the appliance is connected.

I normally advise purchase of an item I'd be happy to use myself, and in this case I'd be perfectly happy to recommend certainly the one I bought from Lidl........LINK, I may buy an Aldi variant to compare soon


Looking at this advert would imply it's suitable to be used while the battery is connected to the car


Brian