Charging a leisure battery with a laptop charger.

[Buick Mackane]

Thinking of buying a 12 volt 7-AH Leisure battery to power my yaesu FT-817 when going portable, I don't really want to spash out on a dedicated battery charger if i don't have too, So was thinking of using an old laptop charger (Have a few) Theres a few videos on youtube of people charging batteries from a 19v laptop charger with a 12v bulb in series with the charger to limit the current.

So is this advisable or could it damage the battery in the long term ?


Cheers.

[lbcomms]

It will cook the battery, assuming you are talking about a lead based type like an SLA or AGM. When it's fully charged it won't draw any current, so the light bulb will not limit it to its maximum allowable 14.5V or so. It will then heat up, boiling or venting electrolyte and in severe cases buckling the lead plates... one dead battery is the result.

You could design and make a regulator to limit it it to say 14.3V (for a bit of a safety margin) but less hassle and quicker to just buy the correct charger.

[The Collector]

Ideally you need a proper car battery charger set to low amperage charge setting (1amp etc) ideally with a maintenance cycle on it to keep it "conditioned".

[KiloBravo312]

Hi there.
I’ve got a Halfords 6 in 1 battery bank. Its a 16ah battery (wet) and it last 8 to 10 hours for my DX’ing. Its was £70 odd pounds.
It has a 3 pin socket, usb port, 12v socket, light, jump starter and tyre inflator. Its a no brainer!
Only downside is it’s heavy and bulky.

https://www.halfords.com/motoring/batte ... 54898.html

[ghost123uk]

I agree with all that has been said above.

To add, I reckon your 7ah battery would not keep going for long (though I have to admit that I do not know what the power consumption of an FT-817 is).

Also worth bearing in mind that *any* lead acid based battery will soon get damaged and not hold a charge if you ever let it drop below around 11.8 Volts, and this rule *does* still apply to batteries labelled as "deep discharge" types.

[Buick Mackane]

Sorry for the delay in replying folks been busy the past week, Yea kinda what i thought but just wanted to confirm it. Guess i'll just need to bite the Bullitt and buy a charger, Just goes to show that a lot of electronic based youtube videos are pure BS.


Thanks for the info