Homemade battery maintainer?

Anyone have a schematic for a homemade battery maintainer? I'm getting tired of batteries, even brand new batteries not hooked up, discharging if not used for a few weeks. No, not an isolated incident, I've had this happen on numerous batteries over my riding years.

I've seen them on parts house websites, and they look like they'd be pretty easy to build (I'm pretty good with electronics).

A trickle float charger is very simple. Just get a small transformer and a rectifier. Whether it's a half wave or full wave setup doen's matter as long as the positive peaks of the recified sinewave are at about 15v or so.

As the battery voltage goes up, less and less of the sinewave will actually be used to push current through the battery. That way it's self leveling, or in other words, let's the battery voltage "float".

However, if you don't already have the parts, it's probably cheaper to just buy a trickle float charger.

You have kids???
Take any of their, game ,phone, camera the little black bxes and use them!!!!!!!!!!!!

10,11,12 volt will work!!!

You probally have 3 or 4 in your house right now!!!

They are cheap at Harbor Freight.

www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=42292

That says $7.99, but if you watch they put them on sale for $5 at the stores frequently.

A somewhat unusual method is to use a 2 amp automobile battery charger plugged into the light bulb socket on an automatic garage door opener, which gives a brief charge each time the door is opened or closed.

This one's on the house. :laugh: :laugh: :laugh:

Good Fortune!

If you really want the battery to last you need a temperature compensated charger that tracks the battery voltage with the right temperature coefficient. I have a design that I did some years back that I use on mine. It's a PDF document available to anybody who wants it.

JakeB, that's perfect and at a great price...if it works. I've had mixed success with HF stuff. What do the rest of you think of this item?

bountyhunter, where can I download that pdf?

Sorry Patton, heh, my house is too old for that luxury!

polkat wrote:

bountyhunter, where can I download that pdf?

I have never figured out how to post a PDF here. Send me a PM with your email address and I will send them directly.