OT - Wynall battery charger for car batteries

[Jim S]

Hi, sorry if off topic but thought somebody may be able to help

A neighbour has just cleared out his garage and has given me an old 'wynall' car battery charger.

On the front there is a amp meter; one dial for volts and another dial for amps. Both the voltage and amp dials just can be rotated from 0 - 7 . No other markings!

What do i need to set these dials to for charging different 12 V batteries. I havent a clue!!

Ive tried the wynall website but thats not much help, but i think my charger is a bench type.

Many thanks

[Dave Plowman (News)]

Given that pretty well all car batteries are of the low maintenance type these days, I'd get rid of it and buy a modern suitable charger. Old chargers like these have no regulation and will cause the battery to gas when fully charged. You don't want that with a 'sealed' type.

[Ian Stirling]

How heavy is it?

Do you own a voltmeter?

[Jim S]

It is very heavy and do own a multimeter, if thats any help.

[N. Thornton]

It does depend on the battery - all the low maintenance car batteries I've played with have been wet cells with some excuse of a low maintenance mechanism, probably a water reforming catalyst. Wet batts can still charged OK with an old Wynall thing. It is recommended to keep an eye on the ammeter though, and disconnect when i drops to maybe 1.5A. I agree new ones perform much better, but if its just occasional charging wet lead acids, an oldie will work, same as it always did.

Re the dials... I cant imagine the details, but if you twiddle them to give 4A charging for a typical car battery youre about right.

A Wynall quite likely has a metal rectifier in it, which gives it a quite crude amount of control.

Regards, NT