The Point’s Picks for June 15th

It’s been a while since I’ve done one of these summary posts. But much has transpired in recent days. So to revive this habit, I’ve once again assembled a curated listing of attention-holding items from the last week or so.

Transit of Venus

A rare transit of the planet Venus across the face of the sun occurred in the early evening hours of June 5th. Unfortunately for some of us (myself included), the weather was less than ideal for viewing. But the action was broadcast via the Internet in real time from multiple sources, and I blogged about it here, and tweeted the major events as they happened, as much as possible. You can find much of the global twitter activity related to the transit of Venus here.

Venus Third Contact, From Keck Observatory

Ryobi Cordless Drill Review

At the invitation of Building Moxie and The Home Depot, I thoroughly tested and compared two Ryobi cordless drills: The Ryobi 18V 1/2″ Nickel-Cadmium (NiCd) Cordless Drill, and the Ryobi 18V Lithium-Ion (LI) ONE+ Compact Cordless Drill. The results were posted here. As of late Thursday, my review had the highest score (219) on The Tweeted Times DIY Projects Home and Garden page. W00t! :-D

The bottom line of my comparison was the discovery that each drill, armed with a standard size 18V NiCd or 18V LI battery, respectively, had essentially the same performance: Each could drive just a little more than ninety 3″ deck screws all the way into pressure treated pine, on a single battery, before requiring a recharge.

This result seems to call into question the advertised claims of the manufacturer that LI outperforms NiCd. But if you consider that the LI battery is both considerably lighter and smaller than the equivalent NiCd battery, it becomes obvious that, pound-for-pound, LI indeed outperforms NiCd. I believe that the standard Ryobi 18V NiCd and 18V LI batteries have been respectively sized so as to provide equal levels of performance, when fully charged.

Now, here are some photos that weren’t included in my review. They’re infrared images taken just at the point when each drill’s battery became too spent to turn screws, immediately following an extended period of continuous use:

NiCd Cordless Drill and Vdc

Ryobi 18V 1/2" NiCd cordless drill: Surface temperatures and VDC

 

 

 

 

 

 

 

LI Compact Cordless Drill and Vdc

Ryobi 18V LI ONE+ compact cordless drill: Surface temperatures and VDC

 

 

 

 

 

 

 

 

The intent was to determine how warm each drill/battery combination became following heavy use, and where on its surface. The final DC voltage of the battery was also measured via a multimeter, and then stored, along with the temperature data, in the thermal image itself. The good news is the warmest temperature was only 102 °F — certainly nothing that’s going to burn your hand. Also, the 18V LI battery is cooler than the 18V NiCd. Either its casing is better insulated, or it’s more efficient and just doesn’t dissipate as much heat (I’m assuming the latter).

But what I found counter-intuitive was the fact that the NiCd battery bottomed out with a voltage of 19 volts DC — still above its nominal 18 volt rating (when fully charged, this battery carries a potential of about 21 volts DC). Also, the 18V LI battery, when fully charged, only measured 8.6 volts DC at its terminals (it measured 4.1 volts DC after it ran out of juice). I suspect the Ryobi 18V LI battery has a safety mechanism built into it that prevents its full charge from being exposed at its terminals when the battery is not actually in the tool. But I’ve not yet found anyone who can confirm this.

Electrics To Curl Your Hair

No, I’m not talking about curling irons. I’m talking about the ghastly photos of electrical sins exposed (no pun intended) by Sean Lintow’s most recent Safety Sunday Series posting “How not to do Electrical” on his Homeowners and Trades Resource Center blog. He talks about how drywall often obscures really bad electrical work, then scares the coulombs out of us with some truly horrifying photos; all out there in the open, all from the same house. But don’t listen to me…go take a look for yourself.

Home Inspection vs. Energy Audit

Recently, I’ve become acquainted with James H. Bushart, a certified energy auditor, BPI Building Analyst, and professional home inspector from Missouri, via the home performance community on Twitter. James has a really great blog, Houses and Stuff, that I’d encourage anyone interested in home performance and energy efficiency to follow and spend some time getting familiar with. I particularly enjoyed his most recent blog posting, “Difference Between the Home Inspection and the Energy Audit“. Nice meeting you, James!

That’s it, ’til next week. Have a great weekend, and a very Happy Father’s Day to all you dads out there!

About John Poole

My interests include historic homes, architectural preservation and restoration, improving the energy performance of old houses, and traditional timber frames.
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5 Responses to The Point’s Picks for June 15th

  1. Nice recap & thanks for including my article. Pretty cool to see the Infrared shots – nice job on getting a good focus on them
    As for the LI – I am curious if there night be a bad cell or connection which could have resulted in the stated test results in your review. Do you know of anyone else with the same setup to see what they get?

    • John Poole says:

      Thanks very much, Sean!

      Regarding the 18V LI battery, that’s what I thought at first. I had two batteries, and both were about 4 volts when unpacked. Both charged up to 8.6 volts. I contacted the Home Depot folks, since I first suspected that the charger itself was the problem, that it wasn’t realizing it hadn’t reached a full charge yet on either battery. They loaned me with a new charger from one of their stores. But I got the same result. So I next obtained a new set of batteries from them. And I got the same result using either charger. I went ahead and did the test anyway, with each LI battery exposing only 8.6 volts. Each LI battery did the same amount of work as its equivalent NiCd battery, and was spent at about 4 volts.

      What I am wondering is, if the battery some how deliberately exposes a much lower potential, just enough to get the tool initially turning, and then when it senses it’s supplying power to a tool, and not, say, a human being, or some other ground source, it ups the exposed voltage (all for safety / shock prevention). But I’m just speculating; I don’t know that for sure. Even though the test is over, I’m really curious as to why they behave this way, and am looking for a contact at the manufacturer who can tell me for sure if this is the case….

      ~ John

  2. Jim Bushart says:

    Good stuff, John. I appreciate your adding my article to the mix. I always enjoy reading your blog.

    • John Poole says:

      Thanks very much for the good words, James! Like I said, I really enjoyed your article. It’s always good to get great insights on these things from the people who are out there doing them. And I’m glad you enjoy my blog, too.

      ~John

  3. John Poole says:

    Hi Alexandra,

    Glad you found this summary useful. I really need to discipline myself to do these more often. There’s so much great and useful knowledge in our various blogs and on Twitter, and sometimes summaries like this are good focal points for things people miss.

    And yeah, Sean’s photos are excellent!

    ~ John

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