Flatfish
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Winch electric needs question
I’m putting in a land based winch to pull our boat up out of water and over a small sand dune into the woods for winter storage, about 100 feet.
Winch is rated 3500 lbs. boat is a 14’ 3 bench row boat with a 100 lb motor, probably all told about 350-400#. Specs says winch will pull around
80-100 amps DC using those numbers. What kind of rated battery should I get given it’ll take around maybe 3-5 minutes to pull that distance? Thanks
in advance!
[Edited on 6-25-2025 by Flatfish]
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chippy
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I would go with 650 CCA or more.
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mtgoat666
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Quote: Originally posted by Flatfish  | I’m putting in a land based winch to pull our boat up out of water and over a small sand dune into the woods for winter storage, about 100 feet.
Winch is rated 3500 lbs. boat is a 14’ 3 bench row boat with a 100 lb motor, probably all told about 350-400#. Specs says winch will pull around
80-100 amps DC using those numbers. What kind of rated battery should I get given it’ll take around maybe 3-5 minutes to pull that distance? Thanks
in advance!
[Edited on 6-25-2025 by Flatfish] |
Sounds like you are operating this winch only a couple times per year. For very infrequent use, I would use a manual winch or come-along. If you
have your heart set on battery power, try using your suv or truck battery since you are only using it once every few months…. This way you avoid
hassle of storing and trickle-charging a battery you use infrequently.
[Edited on 6-25-2025 by mtgoat666]
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Maderita
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An interesting question. My experience with electric winches on 4x4s is that they draw a lot of power from the battery. It is best to have the engine
running at 2,000 to 2,400 rpm while operating the winch. The increased voltage from the alternator makes a big difference. A standalone battery will
provide less power to the winch and deplete the battery quickly.
Another big variable in winching is the number of wrap layers the wire rope has around the drum. Pulling force is reduced with each additional layer
of wrap. Fewer wraps = more pulling power and slower line pull speed, and probably the lowest power consumption.
Are you carrying a winch and car battery to the site? Purchasing the items for this sole purpose? Why not borrow the battery from a car?
I could likely figure out several better solutions for the task, particularly if you can get a motor vehicle (truck or ATV) anywhere close. You can
use a pulley attached to a tree (aka: snatch block) to redirect a wire rope or nylon/polyester rope, or use it to double-back toward the beach. Then
pull with the vehicle. Super easy.
An old climbing rope can be rigged with a "Z-pulley" system block for a 2:1 mechanical advantage.
A manual come-along would do the job easily, using a long rope or strap for extension. Several shortenings of the extension rope would be needed as
you make progress.
Removing the outboard will make the job easier. Would you really want the outboard sitting out all winter?
The Baja way is to purchase a 6-pack of cerveza from Oxxo. Then invite 3 strong amigos to help carry the boat 
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richm
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Heat will be a limiting issue. Check the battery capacity in Amp Hours and the specs for a maximum continuous discharge rate.
The maximum continuous discharge rate for a lead acid battery is typically quoted as something like "C/20" where "C" is the rated capacity of the
battery in amp hours.
So for a 65 amp hour lead acid battery, C/20 would be 3.25 Amps maximum continuous discharge rate.
Above this rate, connectors can melt, become more resistive, heat even faster, and have thermal runaway.
Lithium batteries have much higher discharge rates in the 1C to 2C range. So a 100Ah lithium battery would be far better for this use.
You can find good recommendations for lithium batteries on:
https://diysolarforum.com/forums/beginner-friendly-plug-n-pl...
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chippy
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| Quote: Originally posted by richm | Heat will be a limiting issue. Check the battery capacity in Amp Hours and the specs for a maximum continuous discharge rate.
The maximum continuous discharge rate for a lead acid battery is typically quoted as something like "C/20" where "C" is the rated capacity of the
battery in amp hours.
So for a 65 amp hour lead acid battery, C/20 would be 3.25 Amps maximum continuous discharge rate.
Above this rate, connectors can melt, become more resistive, heat even faster, and have thermal runaway.
Lithium batteries have much higher discharge rates in the 1C to 2C range. So a 100Ah lithium battery would be far better for this use.
You can find good recommendations for lithium batteries on:
https://diysolarforum.com/forums/beginner-friendly-plug-n-pl... |
I was assuming it was gonna be connected to a vehicle when he said "land based". without a running vehicle your lithium suggestion is spot on.
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Tioloco
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Flatfish- This will be adequate. Just need to out the battery on a trickle charge maintainer when not in use.
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Flatfish
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| Quote: Originally posted by Tioloco |
Flatfish- This will be adequate. Just need to out the battery on a trickle charge maintainer when not in use. |
Yup. We have a trickle charger. Thanks. For clarification for all who responded, the height from the shore to the cabin is about 12 feet. We have been
using a hand powered winch for years, but two things. It was only a 12 footer and the 5 hp motor we could carry up and down the dune as needed. No
problemo. Now it’s a 14 footer with a 20 hp motor and we are getting older 🤪🤪. No neighbor kids to call on later in the fall. This is Lake
Superior btw. I’ll look into a 650 CCA or larger and talk to the guys at the battery places. BTW- access to the winch is out of reach of vehicles
hence the question. Harbor freight had a killer deal on a winch and I snagged it up.
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Tioloco
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| Quote: Originally posted by Flatfish | | Quote: Originally posted by Tioloco |
Flatfish- This will be adequate. Just need to out the battery on a trickle charge maintainer when not in use. |
Yup. We have a trickle charger. Thanks. For clarification for all who responded, the height from the shore to the cabin is about 12 feet. We have been
using a hand powered winch for years, but two things. It was only a 12 footer and the 5 hp motor we could carry up and down the dune as needed. No
problemo. Now it’s a 14 footer with a 20 hp motor and we are getting older 🤪🤪. No neighbor kids to call on later in the fall. This is Lake
Superior btw. I’ll look into a 650 CCA or larger and talk to the guys at the battery places. BTW- access to the winch is out of reach of vehicles
hence the question. Harbor freight had a killer deal on a winch and I snagged it up. |
Sounds like a cool set up. If you can post a picture, that would be great. (Of the boat, beach and water)
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BooJumMan
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I'm a fan of LiFePO4 batteries in general, and they have come down a lot in price recently and most likely cheaper than a true deep cycle lead acid.
If you check the specs for maximum draw (amps), most should meet the needs of the winch. I would base the capacity (amp-hr) off the worst case
scenario and then add additional 50%. If your trickle charger charges LiFePO4, then Lithium will probably be your best bet. CCA's are usually
associated with starter batteries which are designed for short high load applications, so most likely won't be listed on a Lithium. If you want to
stay with a flooded lead acid, definitely look into a true deep cycle battery made by companies like Odyssea and Optimia.
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Timo1
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Half bury some round logs on your tow track to really decrease the draw
sold out and got out !!!
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Flatfish
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Winch install update
Here’s the finished install. Inflatable boat rollers coming tomorrow high should make the whole thing easier.
   
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