PDA

View Full Version : battery tender


N3LYT
06-14-2012, 08:39 PM
I was hearing a noise that sound exactly like an old record player when the record came to the end of the record . I heard it on 10 from over 300 yards away and in the mobile as I came up the drive. I killed power to the entire house and it went away started tripping different breakers and narrowed it down to the garage. Started tripping garage breakers and found the battery tender hooked up to my VW that sits for weeks on end. It's a little 2 amp charger so the garage overhead wire must be a exact multiple of 10 meters got to look into that makes a really good 10 meter tx antenna. Wonder how many other things are out there like that we drive by ever day.

Radio
06-14-2012, 08:48 PM
Put about 50 ft of extension cord in the circuit and see what happens.

If you leave it rolled up it might act as a choke.

Andy N1ORK
06-15-2012, 06:03 AM
You may also try clipping on some ferrite beads on the charger's power cord. Loop the cord through the bead a couple of times too, if you have the room.

N3LYT
06-15-2012, 08:28 AM
I have 2 exactly alike one is quiet the other is noisy the noisy one is free to a good home. You guys are right but an extension cord or beads would be pushing the limits of equal cost of the charger guess you get what you pay for.

NN5I
06-15-2012, 09:27 AM
Me, I make my own battery tender/chargers from small Lambda 8a 15v power supplies. I add a diode on the output to prevent discharge through the power supply when it isn't powered; I connect the sense input after the diode to take care of the diode drop; and I adjust the supply to exactly 13.8v. Then I install it permanently. It floats the battery at 13.8v whenever there is AC from either shore power or the generator, and I never have to worry about the battery when stationary for months. I once bought a box of ten such little Lambda supplies, brand new, for less than $50 on eBay.

wa8yxm
06-15-2012, 01:01 PM
That is a great float charger, but a Battery Tender (TM) or Battery Mi9nder (TM) is a 2-stage charger.. Yours is the last stage.

Add the "Plus" and it adds a 3hird stage (Feature) and that one can really mess up up a radio.(If the product description is to be believed) "High speed pulse desulfacation mode") High frequency pulse means harmonics from fundemental to dang near LIGHT. Check that, there is a blinking LED, that's light.

NN5I
06-15-2012, 01:42 PM
Yes, of course you're right -- a float charger isn't very good for charging a discharged battery. It will do it, actually, but can take several days. The trick is to use a float charger to assure that a battery that is idle doesn't ever get discharged. I do keep an excellent three-stage charger, an Onan, for use if I leave headlights on or something; but for maintenance a float charger with superior regulation is arguably better.

Dry-camping in my motor home, which I do often, I sometimes run the house battery low, and a float charger is not the thing then. When I first started full-timing I would run the generator (starting it with the truck battery if the house battery is too dead to start it) to charge the house battery, but it was pretty slow, too -- several hours. Nowadays, I start the diesel instead; it charges both batteries -- there's a big relay that straps them together when the diesel's running -- and at idle the diesel will bring up a rather dead house battery in way less than an hour. Quicker, and much less fuel expense.

N3LYT
06-15-2012, 06:02 PM
I replaced the camper charger with a 3 stage one and it's very quiet no radio noise at all. When no ones listening I use a small generator to recharge mine through the 3 stage charger when I dry camp it's 45 amp output so it does not take very long to recharge the camper battery. The little thing connected to the VW just over comes the parasitic draw it does voltage track so it's half good. There is some issue with the noisy one because the other one works fine no noise.

KC1BUD
06-16-2012, 12:07 AM
I was hearing a noise that sound exactly like an old record player when the record came to the end of the record . I heard it on 10 from over 300 yards away and in the mobile as I came up the drive. I killed power to the entire house and it went away started tripping different breakers and narrowed it down to the garage. Started tripping garage breakers and found the battery tender hooked up to my VW that sits for weeks on end. It's a little 2 amp charger so the garage overhead wire must be a exact multiple of 10 meters got to look into that makes a really good 10 meter tx antenna. Wonder how many other things are out there like that we drive by ever day.

Years ago before I got my ham license I was listening to shortwave in my basement shop on a wire antenna that I had strung overhead on the floor joists. My young sons (they are now 26 and 36) were playing in the bedroom above me. Imagine my surprise when, as I was tuning the dial their voices came over the speaker crystal clear. As it turned out, the wire which I had pulled tightly and stapled was tight enough to vibrate when they talked and this just happened at a frequency that I was tuning past at the time. Somehow the radio's signal detector circuit saw that as a radio signal. :eek: