Thursday, November 29, 2007

RFI - Radio Frequency Interference Warning: Sears DieHard Battery Charger No. 2871219

Just what I thought I needed to keep the battery in my 1998 ST1100 charged this Winter: The Sears charger shown here even comes with a set of handy connectors (lead, connector, alligator clip), and at $32.99, I thought it was reasonable. This is a relatively new product sold by Sears, and is made in China.

I brought it to the lab to check it out, and I was shocked by the intense level of severe RFI it generated, terminated or unterminated. The interference this device produces would have interfered with all of my ham radio equipment from 160 through 2 meters, according to the measurements I quickly made here using an HF receiver and an ICOM R7000, shown on the right. I have not measured the total radiation levels, but believe they are unacceptable.

We are always on the lookout for RFI, as it tends to get into audio recordings and can be very problematic, so when such a gadget is found, it sets of alarms. In my opinion, this device falls under the category of an "incidental radiator" and its use is prohibited by the FCC when it produces harmful interference to a licensed service, which it does. Fair warning! This polluter of the airwaves is going back.

The Sears 2871219 should, in my opinion, be labeled with an FCC type 15 warning at the very least. These warnings read:

This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) this device may not cause harmful interference, and (2) this device must accept any interference received, including interference that may cause undesired operation.

Of course, that would be for devices that were properly checked and tested. I don't believe this ever has been, nor do I think it would comply with the rules had it been properly tested. The bare circuit board is in an unshielded plastic case with no bypassing or other measures to reduce interference. People are going to leave this device plugged in for extended periods of time in their homes and garages; it produces considerable current and has no visible fuse, and I think is built more like a toy than a proper shop tool. As an "Unintentional Emitter" aka Incidental Emitter, Sears can claim that devices such as light bulbs, battery chargers etc. are exempt from the FCC rules, leaving it to the consumer to find out on his own, and be subjected to the consequences. Still, the FCC is clear on the labeling of devices, and the rules governing interference from consumer electronics. See this for further information.


Anonymous said...

A website is needed where people can post information on products that emit RFI. We are experiencing an influx of garbage products from China that meet no reasonable levels of safety, RFI, utility or lifespan. The federal government has abandoned its responsibility to protect the populace and it is up to the states and cities and the individual to protect themselves. N1IPP

Bob Crowley said...

The rules are in place. Companies take the cheapest way out, and are not induced to comply in this case unless consumers complain, as I have done. The quality of products is largely determined by price and consumer selection. Consumers need to be aware of hazards in toys, food, and electronics, especially. Millions of chargers - "wall warts" - are plugged in all over, wasting electricity, and potentially starting fires. In electronic components, plasticizers used in the jackets of wire sold by retailers, contain various oils, petrochemicals, etc. These are handled by people, and some people even put them in their mouths. I believe that groups like Consumer's Union should do fewer "buyer's guides" and focus more on alerting consumers to these hazards.

Anonymous said...

I want to know why you bought this to begin with. Why did you buy this and not buy one made in America?

Anonymous said...

While I am not a fan of products made in China or the performance of this charger, often the manufacture of the product is outsourced to factory which makes the products to the OEM design spec. So, it may be that the OEM designers chose to leave out the filters and not to meet FCC part 15, not the manufacturer. This may be the case here since it appears this charger is sourced from Schumacher Electric Corporation, Mount Prospect, IL for Sears. You should forward you findings to Sears and Schumacher.

Bob Crowley said...

Yes, certainly the importer is culpable, but also many importers don't get into the designs at all and simply buy the item, have it marked as their house brand, and sell it. I was just looking at this device again last week and it looks like a fire waiting to happen.

Sears was informed. Don't know if they got it. The important thing is to get people to identify and avoid these devices. That's a problem since we are flooded with them. I don't care what country they come from - each home may have a half dozen or more "wall warts" cooking away. What kind of cumulative risk does that represent? I would think that the insurance companies would want to know.

Anonymous said...

I just found that exact warning on my kids ' toy. Why would a toy for a 2 yr old in which you press the letter A and it says A and so on? Are they putting some type of radio transmitters in toys now? If yes, why?