will my idea work?

[jesusn]

hi sup iboats members i was out on my boat yesterday when i got an idea for charging my trolling battary now i know of onboard chargers but they are so expensive ,anywere for 100 to 300 dollars , now. i use car chargers at home to charge my bateries now, but not wile im out in the water so when i run out of trolling power theres nothing i can do but wait till i go home. now heres my idea i want to conect a 12volt power suply to the starting bat ,then a 12volt inverter to the power suply so ill have a plug then ,plug in a tricle cgarger to that and run it to my troling motor giving me 2 amp charge to my troling bat. when the outboard is on . is this a good idea the hole thing cost about 30 dollars compared to 300 and it dosent seem like any kind of hazard so let me know what you think plz thanks guys

 

[Bifflefan]

Re: will my idea work?

You will have to draw that out, because Im not getting it.

I think you are saying, take a battery hook an inverter to it and then plug a charger into that to charge a different battery.

If so, sure it will work in theroy until both batts are dead. But,,, why not just hook the batteries to the motor and forget the inverter and charger. You will not again anything by using the charger/inverter.

 

[tashasdaddy]

Re: will my idea work?

just buy a bigger battery, or use 2 batteries in series for the trolling motor. in principle it would work, but very ineffciently, then you end up with a dead starting battery.

 

[Chris1956]

Re: will my idea work?

How about installing a battery switch connecting the OB to both batteries? Set it to the starting battery to start the motor, and then switch to the trolling battery. It will charge the trolling battery much faster.

It will take a lot of running of the motor to charge the troller, however.

 

[gspointer]

Re: will my idea work?

2 batteries in series is 24 volts. I don't know what you mean by "power supply". Usually to me that refers to something plugged into a 115 volt source. If you are talking about another battery, as others have said, that is very inefficient. You will probably lose over 25% of the power.

 

[JB]

Re: will my idea work?

just buy a bigger battery, or use 2 batteries in series for the trolling motor. in principle it would work, but very ineffciently, then you end up with a dead starting battery.

I am sure TD means use 2 batteries in parallel. In series you would have 24 volts on your 12 volt troller

Your idea will not work to any useful degree. It would take many hours to properly charge your trolling battery at 2 amps.

I think the switch to allow your outboard to directly charge your trolling battery(s) without draining the starter battery is your best solution.

 

[jesusn]

Re: will my idea work?

but why will i end up with a dead starting bat if the outboard charges that one i dont plan on leaving it conected wile not runing the outboard only when its on and i would like to know more about that switch thing how does that work do you conect both bats to it ?are you able to just flip a switch to decide what bat gets charged by the outboard ?

 

[jesusn]

Re: will my idea work?

how many amps does the outboard put out? i have 1983 jonhson 70 3 cyl , ive only charged my starting bat once this year and that was at the begining of the season the outboard does the rest thats why i got my idea cus the only bat i charge is my troling bat and somtimes i forget lol but there is bigger chargers than 2 amp how about 6 amp tricle charger , i mean it really didnt seam like a bad idea an itll save alot of money and i dont see how its posible to end up with two dead bateries , only if i leave the charger pluged in when out board isnt runing other than that i dont see how its a bad idea but i like that switch idea to

 

[Silvertip]

Re: will my idea work?

No -- because perpetual motion has not been invented yet.
1) Using an inverter to convert 12 volts to 110 volts AC to power a battery charger is a losing proposition. Inverters are 85% efficient so it takes 15% more power to convert the 12 volts to 110 AC than you get out of the inverter. So 15% loss off the top.

2) to operate the inverter you need to get 12 volts from your starting battery do you not? Depending on the size of the charger you use, that power plus the 15% loss comes out of the starting battery.

3) A 2 amp trickle charger is like spitting in the ocean. Your troller draws probably 40 - 45 amps at its fastest speed and 20 - 25 at mid range speeds. So in one hour you've pulled 20 - 45 amps from the battery., That means a 2 amp charger would need to run for a minimum of 10 hours to put back on 20 amps.

4) As for charging the starting battery with the engine, the same concept applies. If you took 40 amps OUT of a battery, you need to put it back IN from the engine. If the engine has a 10 amp alternator, that would take 4 hours of running at wide open throttle to replace the used current.

Does this make any sense to you? This is not a practical solution to the shortage of power. Your options are two batteries or one bigger battery. Only if the engine has a fairly large alternator output does a dual battery switch make a practical solution.

 

[jhcreech]

Re: will my idea work?

xxx

 

[MaddysDaddy]

Re: will my idea work?

wow really? why not just charge you batts. at home, i have a wall-mart batt. that i use on the trolling motor, i fish for hours and hours, a few times a week and charge up maybe once a week, i think you batterie is goin bad if you cant fish all day on one batt. please don't hook up a bunch of crazy stuff on your boat it won't be effishent or safe. and you will be laughed at when you need a tow.(or a fire exstinguser)

 

[MaddysDaddy]

Re: will my idea work?

i just can't get over this one!!!!!! why would you want your outboard to run why you are fishing? if the outboard is runing why would you use a trolling motor? a inline charger can be bought for 100 bucks, it would take that much money worth of gas to charge you batt fully. have you ever heard of thermodynamics?

the only thing you need to hook to your batt is a breath-a-lizer, and maybe a strope-light so we can see you from across the lake

 

[timfives]

Re: will my idea work?

hi sup iboats members i was out on my boat yesterday when i got an idea for charging my trolling battary now i know of onboard chargers but they are so expensive ,anywere for 100 to 300 dollars , now. i use car chargers at home to charge my bateries now, but not wile im out in the water so when i run out of trolling power theres nothing i can do but wait till i go home. now heres my idea i want to conect a 12volt power suply to the starting bat ,then a 12volt inverter to the power suply so ill have a plug then ,plug in a tricle cgarger to that and run it to my troling motor giving me 2 amp charge to my troling bat. when the outboard is on . is this a good idea the hole thing cost about 30 dollars compared to 300 and it dosent seem like any kind of hazard so let me know what you think plz thanks guys

Why not just get a battery isolator, and run / charge them off the main alternator of your engine?
T

 

[Silvertip]

Re: will my idea work?

Isolators, combiners, ACR, dual battery switches are simply not a practical solution in this application (or any similar application) where the engine alternator output is not high enough to make a dent in charging a deeply discharged battery. I provided an example why this is not practical. Save the money.

 

[NYBo]

Re: will my idea work?

No -- because perpetual motion has not been invented yet.

For some reason, I was expecting/hoping for such a response!

 

[RickJ6956]

Re: will my idea work?

Yeah, well, Silvertip hasn't seen my leg when the stereo's playing my favorite tunes! (Hmmm ... I wonder if I could tap that to run a flywheel?!?!)

jesusn: Before you do anything, have the battery tested to make sure it's holding a full charge.

 

[The Hammer]

Re: will my idea work?

Make sure the inverter can handle the wattage of the charger, generally 30 one handle laptops computers only.

 

[stylesabu]

Re: will my idea work?

read silvertips thread,he explained it very clearly. your outboard motor puts out between 6-9 amps at wot. its not enough to bring your trolling motor back to life. without running engine all day,thats alot of gas.you would better off getting a generator.

 

[The Hammer]

Re: will my idea work?

Have you considered using the solar panals you can buy at parts stores? Designed to mount on the dashboard and hook directly to the battery. Only downside is it would not charge at night.

 

[bruceb58]

Re: will my idea work?

Have you considered using the solar panals you can buy at parts stores? Designed to mount on the dashboard and hook directly to the battery. Only downside is it would not charge at night.

They put out a couple hundred mili amps aimed at the sun when aimed perfectly. They are only used as a battery maintainer and not a charger.