radio interference from charger

[Mystic51]

Help, My boat still has one battery. I am getting ready to add a second. I bought a Guest smart charger and wired it in. It worked but sent static to the FM and VHF radios. I called Guest and they suggested a different and more expensive model. I made the trade and still the same problem. I called West marine and a tech advised me to try a Charles model. I bought the Charles 5000 10 amp unit. It is advertised to have practically no radio interference. I wired in a pigtail and temporarily have it plugged into an outlet (I do plan to hard wire it).I still have the same static. A teck at Charles sail that I must have another problem like AC and DC wires that are intertwined. I am having fits. has anyone else had problems with radio interference and how did you solve it. We would like to use the unit as a dock side power source and like to use our FM radio. Jeff

 

[Landsend]

Try moving the antenna.

Also try a choke filter and a filter coil on the DC power lines.You can also put in a 2nd battery and hook the radios directly to the battery rather that to the dc circuitry. Good luck.You can find these filters at radio shack.

 

[Don]

welcome to my world

I work at WM and have heard numerous similar complaints and had my own experiences. It appaers tha Charles units are the most susceptible to generating Rf noise given the lack of shielding compared with other mfgs so not suprised the switch didn't help.The other commentor suggested rf chokes which is a good idea and should be placed on both the charger and radio power leads. If that along with proper grounding of each doesn't work, you could verify the coax and antenna connections aren't corroded significantly as a last resort. The above are the most common cures.Good luckDon

 

[Mystic51]

WM suggested the Charles

A tech at West marine said that he did not care for the Guest chargers. He suggested the Charles and indicated that they meet RIAA specs and even in the Charles literature they claim that they emit almost no RF interference. Remember that I had the same problem with the Guest chargers. My antenna is on my stern rail and I do not know where to easily relocate it. I plan to check that wires are not intertwined and then try a filter from Radio Shack. Additional thoughts are welcome. It seems like every time I have a boat problem I can't find anyone else at my marina with a similar experience.Jeff

 

[Jim Wasko]

sometimes

I've seen this problem before on some boats with one or 2 batteries...One thing to check, is to use the mounted VHF if you have one while the charger is on and ask a buddy if he can hear the hum in the transmission while your keying up in HI power.If they hear the hum, shut the charger off and try again, wait five minutes and try again, all the while do this with the FM on, can they still hear you at all?The reason your thinking? Could be a bad battery with a bad cell or just simply a bad battery overall.The other thing too, is that I hate to assume, but most boaters don't install a high quality FM radio on the boat either because it's simply to difficult to get the fidelity you may be accustomed to in lets say your average car. So lets say you take the FM you bought for the boat and put it in your car, you most likely going to get the same noise when the motor is running.SO if your using the charger soley to power anything DC in the boat with the battery switch off, then you'll almost always get a hum, maybe a little one at low volume and more so on the AM side and you probably wont be able to transmit on the VHF either even at low power. (others with higher output chargers might not even have this problem)With the charger on and the battery switch on and still get a hum, could be as others mentioned, intervened wires or as I mentioned a bad battery.But then again, some low end radio's might still reference the antenna ground to the ground wire and if your antenna is on the stanchion, who's to say that the AC shore-power feed doesn't run along or closely under any of the lifelines or the metallic toerail such that it could be inducted into the system?Just my 2 cents, let us know how it went.