Instructables

Minimalist marine battery dolly?

Hi. Been lugging around a 38 lb. marine battery (9" x 9" x 5.5") that cannot be stored in the kayak.  I hate walking long distances with it.

Need something like a compact luggage cart, but very minimalist.  Would like to store the carrier with the battery while on the water, in the kayak storage well.  That way it is readily accessible.

Thinking just a 1/4" plywood "L" shape that hug the battery bottom and back.

I cannot think of how to make the "L" joint (where 2 pieces come together) strong.

Also, need suggestion for a (telescopic?) removable handle.

Do I use an axle?  Thanks much for any suggestions.  This will be a big help!




iceng11 months ago
  1. First .... a Li battery will be half the weight ... with triple the power output capacity  ... but at nine times the cost !
  2. Second .... a light plastic child's garden cart may be all you need  ... with very minor modification ... perhaps you could also use one of the paddles as the handle.
NickMDal (author) 11 months ago
Thanks for the paddle-handle suggestion. It was perfect for this.

The L joint problem was best solved by assembling with corner brackets.

The wheels were challenging but I finally discovered training wheels at walmart :-) Just necessary to install spacers, nuts and lock washers in the correct order to create a free and strong wheel axle.

Luggage dolly approach was highest on the list but I wanted something that would stay attached to the battery when stowed in the kayak.

Here are other problems encountered.

Paddle pulls well if it has the strap as pictured and an easily removable velcro strap to prevent it from pulling out. A little Duck brand carpet grip tape on the front of the battery prevents sliding if I want to push instead of pull.

The battery is held in by a tight fit only and this seems to work well. It comes out easily and is snugged back into the dolly by the battery's weight alone.

Countersinks on the corner brackets all face in and so braces are inside instead of out. This turned out to help stabilize the battery and prevent it from sliding out if tipped the wrong way. Just a lucky turn.

Thanks for all the tips. Its fun to work on a project with a small team of pros :-)
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rickharris11 months ago
Single wheel - Plastic pipe A frame with wheel at apex. Fabric hammock to carry battery - You could use webbing.

This will fold up into a long narrow package to put in Kayak.
Brilliant idea.
RavensCraft11 months ago
You could make the "L" joint using 3" aluminum angle like this:
http://www.ebay.com/itm/3-x-3-x-1-4-ALUMINUM-6061-T6-ANGLE-48-LENGTH-STRUCTURAL-MORE-LENGTHS-AVAILABLE-/321044448205?pt=LH_DefaultDomain_0&hash=item4abfbd83cd

Another idea you could experiment with is to use a heavy duty metal hinge joint instead of
a rigid  "L" joint . The "hinge pin" for the  joint could be a 1/2 inch diameter rod, which
would  also be your axle.  You would  then have to fashion  some sort of side braces to hold
the back and bottom at a 90 degree angle. The advantage  here is that the dolly is foldable.

As for  for the handles, maybe two aluminum adjustable canes like this:
http://www.ebay.com/itm/Walking-Cane-Adjustable-Aluminum-with-strap-/181188630563?pt=LH_DefaultDomain_0&hash=item2a2faf1823

The canes could be fastened to the back  of the dolly using  straps and then riveting the
cane to the straps .  Another method would be some kind of socket that the cane would
fit into and be secured with a pin.



I have a luggage bag that opens like a hand cart wheels and all, got it from the Salvation Army store for 5 bucks.
NickMDal (author) 11 months ago
Cost is a factor for sure. I think our marine battery is designed to handle full discharge well. It is AGM and so has excellent performance. The one we use is optimized for trolling motors.

What do you mean by plastic child's garden cart? Searched google images and no luck.
iceng NickMDal11 months ago
The Lithium Ion battery is
  • half as heavy
  • able to move your kayak three times as far.

Here is a simple toy that can be had at a garage sale for a few dollars
do some cutting, add a piece of plywood and a pull line and go..

A
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NickMDal (author) 11 months ago
Thanks for the help!

At worst, it will be pulled over grass, gravel parking lot. The battery will always be 38.5 lbs. The battery is powering a trolling motor that is a kit for the kayak. This battery is recommended by the trolling motor kit manufacturer.
NickMDal (author)  NickMDal11 months ago
Side note. The smallest luggage dollies are rated for 50 lbs., thought they seem light and flimsy. Guess they work, but seem to be overkill for this. Also a bit bulkier than I'd like since the battery is much smaller than a suitcase.
steveastrouk12 months ago
WOW. That's a crazy weight, What load do you HAVE in the field ???
mpilchfamily12 months ago
Have you explored other battery options? What are you powering with this battery?
iceng mpilchfamily12 months ago
And lugging over water, grass, sand, wood, asphalt, concrete or metal ?