Trickle battery charger

[willix]

I have accumulated a box of plug in chargers over the years for many long gone devices be it old phones to battery op tools ect...

Is it crazy to think I would be able to use one of these chargers for a 12 volt trickle charger?

Its a 120 volt input, 9.6V DC output @ 6 Watt that actually puts out 13.85 DC actual volts on the VOM when I plug it in the wall with no load.

Would this work as an effective trickle charger to maintain a stored car or riding mower battery?

 

[oilboy123]

Should work.

 

[HTSS_TR]

I think it should work if you only plug in the charger 1-2 hours a day, or using a timer to control the time. You don't want to over-charge the battery.

 

[MrMeeks]

Measure the battery voltage after connecting your trickle charger to the batt.. You should have 13 vdc there at the battery terminals.If less,the batt.will not charge .

 

[willix]

I'll hook it up and monitor to see what happens & consider putting some alligator clips on it if the results are productive.

 

[willix]

Well I hooked it up to a low battery that is at 10.9 Volts and it climbed up to 11.5 in less than a 1/2 hr time steadied hanging there at 11.68v rising a slow 10th of a point an hour.

I'll leave it on and check it in the morning & see if it breaks into the 12's.

 

[Kestas]

How is the amp draw controlled? (These things are a mystery to me). I know that amp draw shold be under 2 amps.

 

[The_Jeff]

At 9.6v on the label I expect it's supposed to charge 8x 1.2v nicad cells.

So it's going to put out whatever a 9.6v battery needs to charge, a % more than battery working voltage.

SLA batteries also need a % more, and I don't think this 9.6v charger is going to cut it. However it certainly won't damage anything and seems to be working.

 

[NateDN10]

For lots of "wall wart" transformers have significantly higher open-circuit voltage than they're rated for, but that drops down to (near) the rated voltage when any significant current flows.

My guess is that this won't work, for that reason. But good luck!

 

[meep]

clearly this in an unfiltered, unregulated wall-wart power supply. 9.6V is RMS (root mean squared) which is kind of like an electrical average. It's not a smooth, steady voltage. Your volt meter is reading the peak voltage, 13.85. This will be safe as a battery maintainer. The automatic chargers will charge to 14, then kick off, kick back on at 13.

In fact, if you were to leave this connected to a 9.6V pack, it would eventually overcharge and destroy the pack...

I ALWAYS put a fuse inline with any homemade power equipment. Suggest 1-2A fuse for safety. If the wall-wart malfunctioned, that battery could indeed cause a fire. A fuse is your friend.

Mike

 

[willix]

The 9.6v charger hit a wall at and stopped charging at 11.7v and wouldn't budge any higher.

I actually have one of these chargers that is rated 12 volt but it is AC & I am afraid to hook it up.

 

[Vikas]

If you are going to go cheap, pick up similar gizmo from Harbor Frieght for about $5. It is at least designed to do the right thing. Whether it does or not is a whole different question!

 

[NateDN10]

Originally Posted By: willix
The 9.6v charger hit a wall at and stopped charging at 11.7v and wouldn't budge any higher.

I actually have one of these chargers that is rated 12 volt but it is AC & I am afraid to hook it up.


12V AC won't do anything good. You can get a 12V DC adapter from various places online for less than $10, and it should work. You'd probably want to monitor it the first time to make sure the voltage battery doesn't get too high.

 

[morris]

a power supply is not a battery charger. there are lots of electronic sites that show how to build them from scratch.