final trolling motor questions, i promise!

[deermaster]

last questions.

1) if i get a 24 or 36v motor, can i spread the batteries out around my boat so all the weight isnt in one spot?  like can i put 2 under my middle bench seat, one under the back bench seat, and have em all wired together?

2) lets say i get a 24v motor, and it runs on 2 batteries.  can i carry one spare battery, a total of 3, for emergency, and take one of the used batteries off and put a fully charged one on, or do they both have to be equally charged?

3) if you run a 105 motor at 50%, is it giving you 52.5 lbs of thrust, or is the 50%measured in some other way?

4) how long does it take to charge a battery after a normal day of use?

thanks, i think these are the final questions.  i appeciate all the help.

[Wayne P.]

1. You limitations are how much wire you have.

2. Your run time will be affected by the capacity of the lowest discharged battery

3. 50% is pretty much 1/2. Determining exactly what position of the speed control equals 50% may be impossible without an ammeter.

4. Charging time is determined by the amp output of your charger    and the amount if discharge you need to recover. How long you run your trolling motor and at what setting will affect the discharge rate. Since you won't have any idea what the total discharge amount is, a good "rule of thumb" is overnight to fully recharge.

[XcoM274]

You can charge the batteries faster but they will lose discharge cycles (basically lose total life) if you do. I charge my battery on 6amps which is fairly slow, and takes more than a night for a full charge, but I've seen chargers that will run on 40amps and charge the whole thing in an hour. It just comes at a cost to the battery's longevity...

[surfer]

1.  Yes.  Be careful when wiring together though.  It is harder to visualize the wiring when the batteries aren't next to each other.

2.  You are complicating things.  Cary an oar.  It's lighter, less susceptible to problems, and you are never going to use it anyways.

3.  uh probably.   ?

4.  10amps per battery will charge the batteries overnight for most situations.  I disagree with the slow charge theory.  The less time the battery acid is out of balance (discharged) the less time for the plates to become sulfated.

Ask away.  That's why we are all here.  To share info and experiences.

[NBR]

If I remember correctly you have a small boat. You need to consider the weight limits on your boat.

[sneaker]

One more comment can't hurt can it? Don't substitute a fully charged battery in a 2 battery string for a dead one. It will result in badly over discharging the remaining battery, possibly reversing its output polarity, and it becomes toast. If you want  back power  up you need 2 additional batteries or a pair of oars.

Make sure your positive battery connection  is a RED wire and the Negative a BLACK one. Then you are much less likely to reverse the connections. This means the + red lead of batt 1 must become a black lead before it connects to - of batt 2.  

However if you are only powering a motor with the battery, reversing one battery will not harm anything, you simply won't have any power at the motor, ie one battery output will cancel the other. On the other hand if you have other electronics connected to the reversed battery, they might be damaged.

I use a smart charger that charges the battery at 30 amps until it is 75% charged and then falls back to a 10 or lower rate until the battery is 100 % charged. You can select the initial charge rate for 2-10-30 amps so it will work for smaller batterys also. Bought it at Lowes for 75 bucks and it works well. Made by Vector.

[HPBB]

one thing to try when wirering up your boat when "speading" the batteries out. On my 15 footer if I put the 109 36volt in it I have two batteries in the back and one up front. this is a way to make sure you do not hook the wrong wires up. get different color. I use red for + and black for - just like everybody else. but the jumper wires use a blue or yellow wire. then you know what wire is what

[scbassin]

A 24v t/m will be big enough on your boat. Put the 2 batteries together so you don't have a wiring problem. You will not need to carry the x-tra battery as you could probley run for 2 days without charging them. Get 2 31 series batteries & your set.

[Raul]

Just let me ask, are you planning to fish electric motor only lakes ?

Cuz ........ I don 't get it  :-[

Lots of batteries = lots of weight ----- better a small outboard, like a 2.5 HP plus 1 battery for the TM.