Low power draw trickle charger needed ... great idea if it can be figured out

[SeaMasterZ@aol.com]

Like most of us, I am getting older, and the idea of cranking a 3 ton boat by hand is daunting to say the least.<br /><br />Idea:<br /><br />Mount a battery box on the boat trailer and hook it to the electric boat winch, blah blah blah, standard set up<br /><br />heres where it gets different<br /><br />I want to tap into the running light circuit and have the winch batt get trickle charged, would also want to mount few photovoltaic cells to keep it "topped off" so to speak<br /><br />how low of a drain can I put on the system and still have a useful flow of power into the winch batt? I dont want to pull more than a few amps (2 or 3) so the taillight circuit can support the charger. (yes I know I can run a fused power tap from the truck batt back to the winch batt, but Im trying to be clever here)<br /><br />

 

[Silvertip]

Re: Low power draw trickle charger needed ... great idea if it can be figured ou

Re: Low power draw trickle charger needed ... great idea if it can be figured ou

The problem with your idea is that "you" don't determine how much power goes to the battery. The battery decides how much it's going to take from the source. Therefore, if the battery wants 10A from the tail light circuit, pop goes the fuse before you ever left the driveway. An alternate setup would be to run a separate, circuit breaker protected, heavy gauge line to the trailer directly from the tow vehicle battery. The trailer battery (and the one in the boat for that matter) could be charged enroute to the water. Add the solar panel to keep things topped off while the trailer is stored. I use a solar panel in my shed to keep the tractor battery topped off since there is no AC out there from which to run a battery charger. Works fine.

 

[SeaMasterZ@aol.com]

Re: Low power draw trickle charger needed ... great idea if it can be figured ou

Re: Low power draw trickle charger needed ... great idea if it can be figured ou

The problem with your idea is that "you" don't determine how much power goes to the battery.<br /><br />See, thats the part that Im trying to figure out, how to take 2 amps of 12v power and step the amperage down and maintain voltage so it can "trickle charge" the battery while driving along

 

[briannh1234]

Re: Low power draw trickle charger needed ... great idea if it can be figured ou

Re: Low power draw trickle charger needed ... great idea if it can be figured ou

12 volt 2 amp self reseting circuit breaker. This is from another post.<br /><br />If the winch battery goes bad and you pull into a rest stop and shut off the engine - I would think this circuit could kill the starting battery on your tow rig, or at least drain it a lot. So - only use this when the tow rigs engine is running.<br /><br />I've been looking for these circuit breakers myself. Walmart doesn't have em and I haven't found any at the local auto parts stores.

 

[Silvertip]

Re: Low power draw trickle charger needed ... great idea if it can be figured ou

Re: Low power draw trickle charger needed ... great idea if it can be figured ou

A two amp breaker is not a step down device. It is simply a switch that, in your application, would cycle continually on and off until it failed. The numbers being used here don't make sense either. You say you want to take "2 amps and step it down to trickle charge the battery". 1.5 to 2 amps "is" a trickle charge. You can't simply pluck two amps from the tow vehicle battery. You can take 12V, feed it to constant current regulator however. Try Radio Shack but you may find the cost prohibitive.

 

[Silvertip]

Re: Low power draw trickle charger needed ... great idea if it can be figured ou

Re: Low power draw trickle charger needed ... great idea if it can be figured ou

One last thought -- Although inefficient, you would use a 12V 110 inverter installed in the trunk/bed of the tow vehicle. Install a Schumaker (or equivalent) battery maintainer (1.5 amp output) in the boat. Plug the maintainer into the inverter while on the road. At home, it can be plugged directly into 110 to maintain the battery which would eliminate the need for it on the road in the first place.

 

[SeaMasterZ@aol.com]

Re: Low power draw trickle charger needed ... great idea if it can be figured ou

Re: Low power draw trickle charger needed ... great idea if it can be figured ou

Thanks for the ideas, its given me a few avenues to wander down ... a decent RV batt should be good for dozens of crankings on the trailer before it goes flat anyway

 

[DangerDan]

Re: Low power draw trickle charger needed ... great idea if it can be figured ou

Re: Low power draw trickle charger needed ... great idea if it can be figured ou

I use a solar panel in my shed to keep the tractor battery topped off since there is no AC out there from which to run a battery charger. [/QB]

You have sunlight in your shed? doesn't your tractor get wet?

 

[Andrew Leigh]

Re: Low power draw trickle charger needed ... great idea if it can be figured ou

Re: Low power draw trickle charger needed ... great idea if it can be figured ou

Hi<br /><br />Why do you want to trickle charge? Surely your ultimate aim is to have a fully charged winch battery at all times?<br /><br />If you trailer circuits are the same as where I come from then when you connect into your tail light circuit you will automatically connect into the tow vehicles electrical circuit (and therefor alternator and charging circuit). Your additional battery, depending on state of charge, will draw the required current from this circuit to return the battery to full charge.<br /><br />As the battery reaches it's full charge the current will automatically drop, the voltage will lift and the battery will enter a state of "float charge" with the tow vehicles circuit being used to supply just enough current to maintain full charge.<br /><br />You don't need a charger, you already have one. The problem is that if your alternator / charging circuit is under rated and both batteries are in a state of low charge the batteries may draw current excess to what your alternator is able to provide leading to damage.<br /><br />Visit your local auto electrician and they will be able to help you. The secondary battery ought not to be a problem providing it is kept in a near fully charged state.<br /><br />Cheers<br />Andrew

 

[Andrew Leigh]

Re: Low power draw trickle charger needed ... great idea if it can be figured ou

Re: Low power draw trickle charger needed ... great idea if it can be figured ou

Another thought.<br /><br />Why not wire your winch to the tow vehicles circuit and use the tow vehicle battery as your power source?<br /><br />Cheers<br />Andrew

 

[Silvertip]

Re: Low power draw trickle charger needed ... great idea if it can be figured ou

Re: Low power draw trickle charger needed ... great idea if it can be figured ou

Danger Dan -- Yes I do have sunlight in my shed. It's called a "window". The panel is mounted in a window with south exposure. Works great.