trickle charger

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Dec 11, 2002 | 08:24 AM

Fordzlla

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From: Ontario, canada

trickle charger

I just scrapped an old scanner that stopped working on me .
The power adapter got me thinking. It's one of those little black boxes that plug into the wall and give DC current. It's marked as 15VDC 1A output. I'n thinking that this may be the perfect thing for slow charging a battery, as I have several in storage for the winter, and set on a timer for maybe 1 hour a day may be the ticket to keep these up.
Anybody know if 15 volts is too much for a battery? I know that most auto systems put out around 14volts.

Dec 11, 2002 | 01:26 PM

Buckarcher

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From: Princeton, MN

trickle charger

I would think that 15 volts would be fine. If you look on the voltmeter on the dash I think they don't go red and show abnormally high voltage until 18 volts. That should leave you plenty of wiggle room, (20%)

Dec 11, 2002 | 01:37 PM

sideout2

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From: Austin USA

trickle charger

I wonder if 1A will do anyting? Just my thoughts. I have a bunch of those things. If it worked I could use it on my boat for the winter.

Dec 12, 2002 | 12:46 AM

Torque1st

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trickle charger

Go to Radio Shack and get a #271-132 (pkg/2) 10ohm 10watt resistor and connect the + lead thru a 10ohm resistor to the + post. You can leave it on the battery continuously if you want then. Change it over to another battery every couple of days or so. Or put it on a different battery one day per week. It does not take a lot of time, and the power pack will not draw much current on a fully charged battery.

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Dec 23, 2002 | 06:02 PM

insainity

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From: Clarksville USA

trickle charger

Oh ive got cold chills thinking about it.But dont pay me any attion im just gun shy.I had a battiery charger blow one up a few feet away one time.The cable end must have arced dureing a power cycle dureing heavy charge.Warning boiling batteries fumes and sparks dont mix they go boom.

So be careful!!!

Dec 23, 2002 | 06:24 PM

bjr23

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From: Eastern WA

trickle charger

Sounds okay and I'm thinking about what you said with getting a 10 ohm, 10 watt resistor and would you just kinda go over the calcs. on how this works. I kinda did that and I'm confused it looks like you only get 10 volts with the resistor in there. I always welcome learning new things. bjr23

Dec 23, 2002 | 08:46 PM

Torque1st

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trickle charger

The calculations for battery float chargers can get kind of complicted due to the charge characteristics of a lead acid battery. My experience with other small current battery charger designs and the availability of parts is why I listed that resistor value. The charger design for a given battery varies with battery construction, capacity, and type of charger. The battery manufacturer usually specifies the type of charger required.

Here we are building a "homebrew" :-) The resistor limits the initial charge current to something the powers supply can handle. It also limits the float current to the battery.

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