Battery Charge rate to high???

[Clive-Cardiff]

Sorry to be the one to bring up battery charging as a topic once again, but I have not seen my problem ever covered.

I have a Halfords "automatic" charger. I keep my leisure battery connected so that it is trickle charged as required.

I disconnected the charger today for just a few minutes and checked the voltage, about 13.8. When I reconnected the charger the voltage went to 14.5 and then rose gradually over 5 minutes to 15.16volts. The charger then indicated that the charge was full and cut back to its normal trickle rate.

The question is, is this charge rate to high? The rate was above 15volts for about 2-3 minutes so is this harmful to the battery.

 

[JeremyClarksson]

I am not an expert in this although I did some training on battery technology in my electronics engineering quals years ago.

I would guess this is not a problem and is in effect the charger testing the battery to find its charge state, it is not long enough to cause significant heat or gassing and it turned off once the battery state was identified.

I would not worry.

 

[RonD]

Clive,

"Jeremy" is quite right.. the charger has technology built in to continually test the batteries charge state and adjust accordingly. Don't be concerned.

Ron

 

[Clive-Cardiff]

Thank's for the info Jeremy and Ron. I was concerned because some years ago (1960's) I cooked a brand new battery for my Vespa, so I didnt want to repeat the trick

 

[ChrisUK]

How accurate is you multi meter ? I'm fortunate in that I get mine calibrated at work one a year, but they can be out. It is the measurung of battery volts that is so critial as half a volt out can be significant.

Last weekend, my Halfords charger peaked out on my wife car at (from memory) about 12.9v AFTER being disconnected for a few hours from the charger.

Was the 15.16v with the charger switched on?

chris

 

[Clive-Cardiff]

Yes I was checking the voltage across the battery terminals while it was on charge

 

[Guest]

My charger, a "Ring Smartcharge 16" has a built-in digital meter and goes to 14.4 volts max. during charging. Never goes any higher that that.

 

[JTQ]

Clive,

Your charger I sense is for starter batteries rather that specifically leisure batteries.

The whole subject is a minefield and to be sure you have to know what the battery maker specifies. Many of the new car starter batteries are from a group called "lead -Cadmium" and these or at least mine requires just over 15 volts to fully charge.

A conventional lead acid battery if there is still anything conventional about, requires 14.4 volts, and the GEL type favoured by German caravan makers its 14.2. These are just guidance values it's all dependant on the trace alloying of the lead and the batteries construction.

Even for a conventional battery so sophisticated multi phase chargers will when they sense a battery is sulphating send out a short pulse of about 15 volts, but not sustain it. These chargers should not be used on GEL batteries.

If your charger holds 15.16 volts for more than a few minutes then I suspect very seriously it's not the right one for the job of charging a leisure battery; however the battery maker is the most definitive source of info. As I said I minefield!

 

[gary]

I'm wondering if the clue in this case is the charger was disconnected and then very quickly reconnected, it strikes me the electronics were going through a 'full' cycle meant for essentially flat batteries and they were somewhat confused before settling down.

The other thing though is most of these chargers have a maximum 15.x to work with and again the electronics control the actual maximum output, if the control chip is faulty it may well give this full voltage rather than the controlled one?

 

[RayS]

Get the CC technical leaflet on batteries from their webiste.

Leisure batteries may be damaged if the terminal voltage during charging rises above 14.2v which will inevitably happen with most charges designed for fast discharge car batteries. See other threads on battery chargers and look at the website for CTEK chargers which have a setting for leisure batteries and which explaint it all quite well.