|Topic Review (Newest First)|
|08-03-2009 06:19 AM|
Originally Posted by davidpm View Post
|08-01-2009 04:30 AM|
Originally Posted by davidpm View Post
|07-31-2009 09:15 PM|
My battery pack with a 17 amp hour battery I figured I had 8 amp hours to work with. As you say a haul may cost 7 amp hours so I figured I was OK for one haul.
But what you are saying is that the battery will not tolerate a discharge at that level?
It is advertized as a sealed lead acid battery. I read that as AGM so it should handle the fast discharge.
What would happen? What about thirty seconds than a few second rest would that matter?
What about a small AGM? They are supposed to tolerate any discharge rate yes? I only need one haul between charges, weight is more important than number of charges.
I've got to tell you this battery stuff seems very tricky.
I'm not arguing with you just trying to understand.
|07-31-2009 08:20 PM|
Thanks, I suspected as much. What I'm hoping is that I'll end up only having to do maybe 50' and my load may be much lower maybe 200 lbs.
It will be easy to find out but it looks like I'll have to buy real battery.
Does sears have the appropiate charger? What would work well with this battery?
The weight is a problem to haul to the beach and back.
If the Sears battery is the same as the Odesey it must be AGM? How did you figure that out, the Sears website give very little info that I could find?
I only need one maybe two hauls between charges.
I thought AGM's could handle faster discharge rates or is that only faster charge rate?
From Sears site:
The PM-1 Platinum Marine Battery from DieHard features 205 minutes of reserve capacity and 1150 cold cranking amps. Provides power for RVs, trolling motors, marine accessories and starting needs. The combination stud/post terminal design allows for multiple connections. Its corrosion-resistant high quality tin-coated brass terminals provide reliable starting power in all weather conditions. Its rugged, military-grade construction features robust casing for increased compression and offers superior vibration resistance.
Does this mean 205 minutes to dead at 25 amps.
100 minutes to half charge at 25 amps
40 minutes at 62 amps
40 / 7 minutes per haul is about 6 hauls
Is that the calculation
|07-31-2009 12:26 PM|
David...well that is simply not going to work.
1. Your battery pack is not designed for a deep cycle load...just a few seconds at a time. The 250 CCA (cold cranking amps) that your pack is rated for means it can deliver 250 amps for 30 seconds before being dead flat (10.5 volts).
2. Any wet cell battery BANK that would be able to handle this job should be sized at at least 300ah to handle the 62 amp load (MAXIMUM current should not exceed 20% of battery capacity...62amps is 20% of 310ah's). By going to an AGM battery you could cut in half the size of the bank quite comfortably and if you want to go further a single Odyssey group31 battery could handle this load since it is able to handle current up to its' rated ah's. The price though is quite a bit higher ($300 or so) but it is a single battery and can be recharged at high rates and discharged quite deeply (80%) and still provide good life cycles. The weight is 77 lbs.
Amazon.com: Odyssey 31-PC2150T Heavy Duty Commercial Battery: Automotive
Your actual amp hour usage per hauling will be 7/60ths of the 62amp draw per hour...or about 7 amp hours per haul...so the Odyssey would allow you to do around 10 hauls on a single full charge before needing to be carried back for a re-charge from a THREE STAGE battery charger.
There may be other approaches to powering this winch such as running electric down to a ACtoDC power supply or buying an old jeep and running the engine to power the winch...... but the Odyssey seems to me to be your best shot at something working reliably. Hope this helps!
EDIT...the Sears Platinum Marine Battery group 31 is the SAME battery as the Odyssey 31 and will save you $50-60 bucks.
|07-31-2009 12:42 AM|
I just ordered this winch
Mile Marker Tough Series ATV/UTV Winches
The specs say that it will pull 500 lbs at 16 feet per minute and use 62 amps. I need to pull probably 300 lbs for 100 feet so my load will be for about 7 minutes.
I have the following portable battery
Booster Pac ES2500KE 12 Volt Jump Starter Booster Pac ES2500
900 peak amps.
17 amp hour battery.
I know some of you are good with figuring out this battery stuff.
Will this battery work and how did you do the calculations?
|07-29-2009 09:34 PM|
I lived in Ocean City NJ for 18 years on the beach and had a Hobie infront of the house on one of the designated "catamaran beaches". I very often sigle handed and developed an efficient way of bringing the boat up from or down to the water by getting the beach wheels under the pontoons and using the jib sail to catch the wind giving me extra power to power up or down the beach.
Usually at the end of our sails in the afternoon there was pretty good wind and many times singlehanding I would not take the main down until after I had it help "power" the boat up the slope of the beach. Your sails can work for you not just on the water, but on the land also.
|07-29-2009 03:56 PM|
I found this suppler or line: Polyester composite double braid prices and specs
I'm not sure how I tell if it is the same quality as Yacht braid, not even sure I care. (Sand ?)
|07-29-2009 01:07 PM|
I had a similar problem with my Hobie 18. 2 could easily move it on beach wheels, one... not so much. Especially up the grade. So, I made a portable beach winch with an ATV electric winch (with remote), a battery, and a 4x4 post that I anchored at the top of the beach. It had about 100' feet of cable so I sometimes had to relocate the winch if the distance was less than 100'. Worked like a charm.
|07-29-2009 11:59 AM|
120 feet with a 5:1 tackle and you'll still need to haul in 600 feet of line. Not to mention--haul the spool of line.
Grainger, Mcmaster, Agway, any farm or industrial supplier...although I have to wonder how that line is going to like getting sand in it all the time, too.
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