12v boat hoist motor

72drptop

Cadet
Joined
Feb 18, 2022
Messages
12
Morning folks, I am looking to add an electric friction drive to my shore master boat hoist. I found a used 12v setup however I really don’t want to use jumper cables or a large battery set up. Has anyone attempted to used a DeWalt 20v battery to work these? I can step down to 12v with a simple regulator I found on Amazon……
 

72drptop

Cadet
Joined
Feb 18, 2022
Messages
12
Well, the lift motor itself I believe has the gear reduction built in. Basically it’s a 12v friction wheel kit made for the hoist I am just thinking why use a car battery or a solar set up when I could just throw in a 20v dewalt battery when I need power…..
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
42,054
Well, the lift motor itself I believe has the gear reduction built in. Basically it’s a 12v friction wheel kit made for the hoist I am just thinking why use a car battery or a solar set up when I could just throw in a 20v dewalt battery when I need power…..
Agree, but how much power (kW or amps, other) can the regular motor produce?

Once this is known then it can be compared to the Dewalt. I don't know, this is why I mentioned the additional gear reducer might be needed
 

72drptop

Cadet
Joined
Feb 18, 2022
Messages
12
Agree, but how much power (kW or amps, other) can the regular motor produce?

Once this is known then it can be compared to the Dewalt. I don't know, this is why I mentioned the additional gear reducer might be needed
Gotchya, I will see if I can get the specs for the motor and see what amp battery they suggest as well.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
49,545
My guess the DeWalt battery is going to go up in smoke as the current draw from the lift motor will be about 20x the DeWalt battery is rated for
 

72drptop

Cadet
Joined
Feb 18, 2022
Messages
12
My guess the DeWalt battery is going to go up in smoke as the current draw from the lift motor will be about 20x the DeWalt battery is rated for
I did run the motor with that battery however only on the bench, I am also wondering what the draw will be with a load on the motor….. you may be correct…….
 

flashback

Captain
Joined
Jun 28, 2002
Messages
3,963
He used a couple of lead acid I think.. with solar to keep them fresh.. he'll pop in...
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
Joined
Jul 23, 2011
Messages
49,545
20 volt drill will pull up to 15 amps max.

A 12 volt boat lift motor on a 10k lift will pull well over 100 amps when loaded
 

72drptop

Cadet
Joined
Feb 18, 2022
Messages
12
20 volt drill will pull up to 15 amps max.

A 12 volt boat lift motor on a 10k lift will pull well over 100 amps when loaded
I thought the same, however when I called Lift Mate they told me their motor draws 13 amps? I confirmed that according to Dewalt their 5AH batteries could work up to 30 amps for 15min....... I also confirmed with Lift Mate that they should only be run on 12v which is not a problem as I can get a 20v-12v step down very cheap on Amazon.
 

nola mike

Vice Admiral
Joined
Apr 22, 2009
Messages
5,362
Here's my thread on my setup. Are you talking about this setup? https://www.boatliftanddock.com/product/706/lift-mate-dc-12v-wheel-assist-motor

Very different than what I ended up with. You already have the lift? Looks like it was made for 12v, and 13a is a lot less than the 30-60a per motor that I'm using. The friction lift that I saw has a 11:1 reduction, or 22 turns of the big wheel for 1 drum turn, which is about 1' of travel. Then you'd have the reduction of the friction wheel-->large wheel, not sure what that is.
@72drptop said that you only needed it to run 1.5 minutes? That seems like you'd get very little lift in that amount of time, what are you basing that off of?

Anyway, I think it would probably work, is probably very slow. If you want to use a dewalt battery, you could just get a 12v system. (Any idea of the amp draw of their tools? I couldn't find it with a quick search). Other ideas would be a tractor battery or a bigger lead acid with a small/cheap solar setup. If you wanted to get more exotic, I bet you could find a li-ion 12v pack that's cheaper than the dewalt.
 

Grub54891

Admiral
Joined
Jun 17, 2012
Messages
6,073
I'm on the fence here. Sure it may work, but those dewalt batteries are expensive to. A regular battery will last much longer without the expense. But that's just my opinion.
 
  • Like
Reactions: KJM

72drptop

Cadet
Joined
Feb 18, 2022
Messages
12
Morning folks, I am looking to add an electric friction drive to my shore master boat hoist. I found a used 12v setup however I really don’t want to use jumper cables or a large battery set up. Has anyone attempted to used a DeWalt 20v battery to work these? I can step down to 12v with a simple regulator I found on Amazon……
Update… so, I fabricated all of my brackets and got everything hooked up this weekend. I ran on the 12v boat battery and it went up and down however very slow and the cables seemed to get pretty warm, so I said hell with it, I wired in the Dewalt 20v battery and it worked awesome, went up and down all the way three times with no issues and faster than the boat battery, everything stayed cool and the battery only went down one bar, I probably could have went up and down another 4 times with no issues…. I appreciate the feedback from everyone, I think I am gonna roll with it, honestly in a normal weekend I am probably only using this 3 or 4 times max.
 

Attachments

  • IMG_3956.jpeg
    IMG_3956.jpeg
    2.1 MB · Views: 6
  • IMG_3955.jpeg
    IMG_3955.jpeg
    1.9 MB · Views: 6
  • IMG_3954.jpeg
    IMG_3954.jpeg
    1.4 MB · Views: 6

72drptop

Cadet
Joined
Feb 18, 2022
Messages
12
I run my lift motor off my boat battery. is that an option?
Definitely however love the idea of not having to use cables running to the boat, also really didn’t want the footprint of a large battery box on my dock. I could have a Small Dewalt battery in an adapter mounted right to the lift,.
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
42,054
Thank you very much for updating
Many folks will read this and your info will be invaluable
 

72drptop

Cadet
Joined
Feb 18, 2022
Messages
12
20 volt drill will pull up to 15 amps max.

A 12 volt boat lift motor on a 10k lift will pull well over 100 amps when loaded
This set up is far from 10k pounds, just an 18’ open now with a 4cyl. The factory motor comps with a 40amp circuit breaker so generally will likely run less than 30amps in most circumstances, I would think…
 
Top