Reprise: Drill winch

Posted by mdurki (vaughan@…>)

I’ll try again:

The battery packs of my 24 volt Craftsman cordless drill are beginning
to show wear, and I know that some of you use an AC drill with an
inverter. I would like to ask some questions about the arrangement.

  1. Is it satisfactory?

  2. Is the draw on the batteries significant?

  3. What size inverter to you need?

  4. My boat has an AC receptacle at the nav table; is that the one you
    are using? and how do you have it hooked up?

  5. What drill are you using? How much torque?

Posted by William A. Cormack (wacormack@…>)

While I can’t tell you from experience what the draw will be I can tell you
that it is substantial. Look around at the nameplates on the drills you
might use and at the amperage rating on the name plate.

My 18v Milwaukee drill produces 495 Inch pounds torque and raises my main
(F-36) with ease and I get two raises on a charge. A 3/8" Milwaukee drill
produces 580 inch pounds torque and requires 7 AMPS at 120 volts, that’s 840
watts. If your inverter is 100% efficient that’s 70 AMPS at 90% that’s 78
AMPS.

I prefer the cordless for its safety. I can’t imagine using a 120 volt
drill in a, potentially, wet cockpit. You would be asking for a shocking,
potentially lethal, experience. You can get a 12v charger for most battery
packs or use your inverter to run the 120v AC charger for your drill.

Bill


William A. Cormack, CPA
Principal and Chief Financial Officer
Whelan Associates, LLC, a Corporate Real Estate Service Firm
100 Faunce Corner Executive Center, Suite 150
500 Faunce Corner Road
North Dartmouth, MA 02747
Voice: 508-984-4100, Fax: 508-984-4101, Cell 508-254-5828
MailTo:wacormack@…


----- Original Message -----
From: “mdurki” <vaughan@…>
To: <freedomyachts2003@yahoogroups.com>
Sent: 11/03/2005 7:56 AM
Subject: [freedomyachts2003] Reprise: Drill winch

\

I’ll try again:

The battery packs of my 24 volt Craftsman cordless drill are beginning
to show wear, and I know that some of you use an AC drill with an
inverter. I would like to ask some questions about the arrangement.

  1. Is it satisfactory?

  2. Is the draw on the batteries significant?

  3. What size inverter to you need?

  4. My boat has an AC receptacle at the nav table; is that the one you
    are using? and how do you have it hooked up?

  5. What drill are you using? How much torque?

Yahoo! Groups Links

Posted by lance_ryley (lance_ryley@…>)

Mdurki,
I use a cordless drill, but I thought I’d comment on it since it is an
interesting and useful exercise. First, you need to figure out what
kind of drill you’re going to use. I found a Craftsman Professional for
the purposes of this exercise with a draw of 6 amps at 120 volts.

6amps X 120Volts = 720 Watts, which is the minimum sized inverter
you’ll need IF the only thing you’re running is the drill AND the
drill’s “startup” draw isn’t much more than it’s running draw. Assume
that it draws 8 amps at startup (probably unrealistic for a drill, but
for edification’s sake) and you have a startup draw of 960 Watts, so
you’ll need at least a 1000 Watt inverter. If you’re only planning to
run power tools and lights, and microwaves, you can get away with a
modified sine wave (Prowatt 1000, about $250), but if you plan to run a
TV, Computer, Stereo, etc, then you’ll need to spend the extra money on
a pure sine wave inverter to avoid damage to the electronics (Prosine
1000, about $625).

Ok, so how long will your batteries run that power drill? Turn AC Watts
into DC amps with the following formula:
AC Watts/12 * 1.1 = DC Amps, so 720 Watts = 66 DC Amps

Doesn’t seem like much, right? Cool. How long can you run the drill?
Assume you’re inverter’s connected to an 8D battery, fully charged, 200
Amp Hours capacity. 200amphours/66amps = ~3 Hours! only… whoops… you
never want to discharge your batteries below 50% - very bad for their
longevity, so you really only have 100 amp hours to play with on that
battery, so you can run the drill for ~1.5 hours - again, assuming a
fully charged battery and no other loads - only, here we go again,
dagnabbed batteries! Higher amp draws deplete the battery at higher
rates, so you’ll really only get about 1.3 hours off that drill. A 100
amp hour battery gives you around 40 minutes before it’s time to run
the engine/generator/windpower/solar/shore charger.

Now that might be enough drilling for the day… if you were just going
to drill a few holes it’s probably not a bad deal, once you get over
the price of the Inverter. Personally, I don’t think I’d want to put
that much strain on a $550+ battery when I could buy a new 24v battery
pack for the drill for around $120.

Or you could spend around $700 for a honda 1000 generator… very quiet,
can run a battery charger, and should have ample power for your drill.
It’s also pure sinewave, so when you’re done drilling, you can plug in
the mini-fridge and the television and watch the game :wink:

Hope this helps explain how you can figure out the loads and inverter
sizes you need for various applications.

lance
bright star
— In freedomyachts2003@yahoogroups.com, “mdurki” <vaughan@i…> wrote:

I’ll try again:

The battery packs of my 24 volt Craftsman cordless drill are beginning
to show wear, and I know that some of you use an AC drill with an
inverter. I would like to ask some questions about the arrangement.

  1. Is it satisfactory?

  2. Is the draw on the batteries significant?

  3. What size inverter to you need?

  4. My boat has an AC receptacle at the nav table; is that the one you
    are using? and how do you have it hooked up?

  5. What drill are you using? How much torque?

Posted by mdurki (vaughan@…>)

I did the W=a x v and came up with the same wattage requirement. But I
assume that one would be using the engine while raising the main, and I
would like to know how long it takes to put the amps back in the
batteries.

Anyone know?

I hadn’t considered the risk of shock in a wet cockpit. It is worth
considering.

Posted by lance_ryley (lance_ryley@…>)

Charging takes differing amount of time depending on how deep the
batteries are discharged. It takes less time to go from 90% to 100%
than from 50% to 60%. There are some formulae for that as well…
search Don Casey’s archives - I’m pretty sure he covers it somewhere.

bright star

— In freedomyachts2003@yahoogroups.com, “mdurki” <vaughan@i…>
wrote:

I did the W=a x v and came up with the same wattage requirement. But
I
assume that one would be using the engine while raising the main,
and I
would like to know how long it takes to put the amps back in the
batteries.

Anyone know?

I hadn’t considered the risk of shock in a wet cockpit. It is worth
considering.

Posted by William A. Cormack (wacormack@…>)

I think you will find that the 50% to 60% takes less time than 90% to 100%.
Most smart chargers taper off the charge rate as the voltage rises and dumb
chargers keep the voltage constant which results in the same thing.

Bill


William A. Cormack, CPA
Principal and Chief Financial Officer
Whelan Associates, LLC, a Corporate Real Estate Service Firm
100 Faunce Corner Executive Center, Suite 150
500 Faunce Corner Road
North Dartmouth, MA 02747
Voice: 508-984-4100, Fax: 508-984-4101, Cell 508-254-5828
MailTo:wacormack@…


----- Original Message -----
From: “lance_ryley” <lance_ryley@…>
To: <freedomyachts2003@yahoogroups.com>
Sent: 11/03/2005 10:49 PM
Subject: [freedomyachts2003] Re: Reprise: Drill winch

\

Charging takes differing amount of time depending on how deep the
batteries are discharged. It takes less time to go from 90% to 100%
than from 50% to 60%. There are some formulae for that as well…
search Don Casey’s archives - I’m pretty sure he covers it somewhere.

bright star

— In freedomyachts2003@yahoogroups.com, “mdurki” <vaughan@i…>
wrote:

I did the W=a x v and came up with the same wattage requirement. But
I
assume that one would be using the engine while raising the main,
and I
would like to know how long it takes to put the amps back in the
batteries.

Anyone know?

I hadn’t considered the risk of shock in a wet cockpit. It is worth
considering.

Yahoo! Groups Links

Posted by lance_ryley (lance_ryley@…>)

yep, got it bass ackwards. it’s that last little bit that takes the
longest. Good catch, Bill.

Lance

– In freedomyachts2003@yahoogroups.com, “William A. Cormack”
<wacormack@w…> wrote:

I think you will find that the 50% to 60% takes less time than 90%
to 100%.
Most smart chargers taper off the charge rate as the voltage rises
and dumb
chargers keep the voltage constant which results in the same thing.

Bill


William A. Cormack, CPA
Principal and Chief Financial Officer
Whelan Associates, LLC, a Corporate Real Estate Service Firm
100 Faunce Corner Executive Center, Suite 150
500 Faunce Corner Road
North Dartmouth, MA 02747
Voice: 508-984-4100, Fax: 508-984-4101, Cell 508-254-5828
MailTo:wacormack@w

----- Original Message -----
From: “lance_ryley” <lance_ryley@y…>
To: <freedomyachts2003@yahoogroups.com>
Sent: 11/03/2005 10:49 PM
Subject: [freedomyachts2003] Re: Reprise: Drill winch

Charging takes differing amount of time depending on how deep the
batteries are discharged. It takes less time to go from 90% to
100%
than from 50% to 60%. There are some formulae for that as well…
search Don Casey’s archives - I’m pretty sure he covers it
somewhere.

bright star

— In freedomyachts2003@yahoogroups.com, “mdurki” <vaughan@i…>
wrote:

I did the W=a x v and came up with the same wattage
requirement. But
I
assume that one would be using the engine while raising the
main,
and I
would like to know how long it takes to put the amps back in the
batteries.

Anyone know?

I hadn’t considered the risk of shock in a wet cockpit. It is
worth
considering.

Yahoo! Groups Links

Posted by rick_simonds (rick_simonds@…>)

I’d think the 110 volt AC drill would be immensely powerful and just
running the engine while you raise the sails, depending on your
alternator’s capacity, that will solve most of the high amperage demand
problem. Even if the alternator won’t cover it all, you’re not running
the drill that long. (I’m assuming your existing inverter is large
enough for this sort of load.)

Another consideration though: An AC drill with just a “go” or “stop”
trigger will work with about any inverter but some reversible /
variable speed drills refuse to use the modified sine wave that most
inverters put out. (There are 2 methods to make a variable speed drill
and I can’t remember offhand what they are and which one works and
which one doesn’t.)

Still, I’d go cordless, but if you go AC, first try running “THE” drill
you intend to use from “THE” inverter you intend to use. Some
combinations work, some don’t.