battery for trolling motor

Discussion and advise about the purchase, care, maintenance and operation of boats

Moderators: JimC, jw

battery for trolling motor

Postby jamesndrumcondra » Thu Sep 24, 2015 6:28 pm

lads. just bought a 54lb thrust watersnake trolling motor , 12volt with a minimum of 13 amps and a maximum of 54 amps. was down at a local battery dealer and he reckons i need one of his super batteries and a charger at a cost of 260 quid....

can someone please tell me hes talking absolute s***e , and if so , what battery will do the job ? can spend up to 80 quid at the moment for one
jamesndrumcondra
SAI Lug Worm
 
Posts: 17
Joined: Sun Jul 19, 2015 3:01 pm
Has thanked: 2 times
Have thanks: 0 time

Re: battery for trolling motor

Postby Bluezulu49 » Thu Sep 24, 2015 7:47 pm

You don't say what you are going to push with this engine. I assume it's a sea boat.

My experience with electric outboards is confined to fibreglass lake boats. My 44 lb thrust engine will push a 17' lake boat with two people at about rowing speed with a 110 amp hour leisure battery for about six hours motor time which equates to about two days of my fishing.

One of these batteries is likely to cost up to €150. A good charger might cost the same though I used a cheap standard car charger successfully from 1999 to 2014.

Standard car batteries are not designed to be heavily discharged and will not last very long if you use them for motive power.

If your boat is heavier than a glass lake boat and is going against tides and wind, your progress is likely to be very slow.
User avatar
Bluezulu49
SAI Lug Worm
 
Posts: 19
Joined: Mon Jun 15, 2009 9:19 am
Location: Dublin
Has thanked: 4 times
Have thanks: 5 times

Re: battery for trolling motor

Postby jamesndrumcondra » Thu Sep 24, 2015 9:33 pm

sorry i should of mentioned its a 13 foot fibreglass boat. not for sea fishing. just thought id post here on the boat section

so a leisure battery of 110amps or more is my best bet ?

and would a car battery do for say 2 or 3 hours fishing until a better battery is bought ?
jamesndrumcondra
SAI Lug Worm
 
Posts: 17
Joined: Sun Jul 19, 2015 3:01 pm
Has thanked: 2 times
Have thanks: 0 time

Re: battery for trolling motor

Postby Bluezulu49 » Thu Sep 24, 2015 10:22 pm

Depending on weight of the boat and payload you might get away with a smaller leisure battery.

I would not advise using ordinary car batteries as they are likely to cost almost as much as a leisure and will not last. I have had recent very bad experience with car batteries used for electric fencers, with a new battery dying after three discharges. This would not happen with leisure batteries.

Just looked at Halfords and they are doing a 70 a/h leisure for €75 and a 115 a/h leisure for €99.

I have no experience of 55 lb thrust motors but would expect considerable battery drain and if it were me I would go for the 115 a/h. Biggest drawback after price is it's weight which will be high.

I don't know how long a car battery would last as they are designed for the supply of large currents for very short periods ( seconds) as opposed to leisure batteries which are designed to deliver lower currents for much longer (hours).

Good luck with whatever you decide to do.
User avatar
Bluezulu49
SAI Lug Worm
 
Posts: 19
Joined: Mon Jun 15, 2009 9:19 am
Location: Dublin
Has thanked: 4 times
Have thanks: 5 times

Re: battery for trolling motor

Postby jamesndrumcondra » Sat Sep 26, 2015 9:11 pm

thats funny , i was in halfords and they said the 75amp would be too much for the motor since it says maximum amps is 54 ?
jamesndrumcondra
SAI Lug Worm
 
Posts: 17
Joined: Sun Jul 19, 2015 3:01 pm
Has thanked: 2 times
Have thanks: 0 time

Re: battery for trolling motor

Postby Bob » Sun Sep 27, 2015 9:40 am

Car batteries are designed to give a large amount of power over short bursts. Get a leisure battery. Try rs online. They have a huge range of batteries. Lots used for automation which would be ideal for what you want, albeit without marine protection so a battery box may be required.
User avatar
Bob
SAI Bait Ball
 
Posts: 138
Images: 1
Joined: Thu Sep 23, 2004 3:19 pm
Location: wexford/kilkenny
Has thanked: 23 times
Have thanks: 15 times

Re: battery for trolling motor

Postby Bluezulu49 » Sun Sep 27, 2015 10:10 am

jamesndrumcondra wrote:thats funny , i was in halfords and they said the 75amp would be too much for the motor since it says maximum amps is 54 ?


The advice they have given you is entirely incorrect. The 54 amps you have quoted above is presumably the maximum draw of the motor. A 75 amp hour battery might supply this current for a little over an hour before it would be fully discharged.

75 amp hours means that the battery can supply 1 amp for 75 hours or 75 amps for 1 hour. The larger the battery in amp hours, the longer it will last in providing motive power between charges.

As I said before I have used electric outboards since 1999 for motive power in lake boats for trout fishing. I am on my third battery. All of them were 110 amp hour batteries and the last one sufficed for nine years powering a 36lb thrust motor.

Buy the 75 amp hour if you must but the 110 amp hour would last longer in terms of range and overall life provided it is maintained.

For this message the author Bluezulu49 has received thanks:
jamesndrumcondra (Sun Sep 27, 2015 10:56 am)
User avatar
Bluezulu49
SAI Lug Worm
 
Posts: 19
Joined: Mon Jun 15, 2009 9:19 am
Location: Dublin
Has thanked: 4 times
Have thanks: 5 times

Re: battery for trolling motor

Postby jamesndrumcondra » Sun Sep 27, 2015 10:58 am

thats grand ill get one of 110amps so. thanks for the info lads
jamesndrumcondra
SAI Lug Worm
 
Posts: 17
Joined: Sun Jul 19, 2015 3:01 pm
Has thanked: 2 times
Have thanks: 0 time


Return to Boat Maintenance, Equipment & Tips

Who is online

Users browsing this forum: No registered users and 2 guests