power inverters???

[minnesotamusky]

I'm wondering if you can use a power inverter to charge up a trolling motor battery? I take alot of 3 day fishing trips and I'm sick of having a dead trolling motor battery after two days. If they do work for charging trolling motor batteries, which one should I get? Size?

[Tom7227]

Don't they change DC to AC? If you're thinking of plugging it into a vehicle it would take a long time to charge one up and you'd burn up a ton of gas. How about using a solar panel? I have been trying to figure out how big a unit you would need to get a battery pumped up - I think there are a number of places that sell a 5 watt unit for about $150 with the controller that prevents an overcharge. When in Canada I hook mine up to the solar collectors they have for the cabins and it works.

[sparcebag]

Watts divided by volts = amps Or 5 W divided by 12 V = 0.4166 Less than 1/2 amp LOOONG Charge time.

I once figured it out and for around $500.00 I would charge a 12 V batt in full sun in one day.A Generator is cheaper and has other uses.

[Whoaru99]

Well, 5 watts at 14V is roughly 0.35 amps.

So, if you have a 105A/hr battery (pretty common size) and run it down to 1/2 power, the solar panel will need to put back roughly 50A/hr.

If the solar panel puts out .35A, it would take approximately 143 hours of good sunlight to recharge the battery.

[minnesotamusky]

A generator is a great idea, but don't they make alot of noise? How big of a generator would I need?

[sparcebag]

You can get a cheap 8.33 amp gen. for I believe around 200 bucks. Google Harbor Freight

[pj4]

you would better off getting a 1000w honda generator. it will be quite, last a long time, run on very little fuel and can use it for more things

[deacon]

Honda's are awesome very quite I wish I had one!

[H20fowlr]

I am guessing you you are talking about charging it from your vehicle. You can use a 300 or 400 watt inverter to run a battery charger, but IMHO, I woudn't waste the the DC to AC to DC conversions and the efficiency losses to do it. If you are talking about charging it with you car/truck , hook the battery in parralell with you rcar/truck battery and iddle the vehicle for awhile. The vehicle alternator will charge the lowest voltage battery in the circuit. Do be careful you vehicle alternator has enough ampacity to hande the load.

[Tom7227]

I am guessing you you are talking about charging it from your vehicle. You can use a 300 or 400 watt inverter to run a battery charger, but IMHO, I woudn't waste the the DC to AC to DC conversions and the efficiency losses to do it. If you are talking about charging it with you car/truck , hook the battery in parralell with you rcar/truck battery and iddle the vehicle for awhile. The vehicle alternator will charge the lowest voltage battery in the circuit. Do be careful you vehicle alternator has enough ampacity to hande the load.

With the price of gas and the risk to the vehicle's electric system it doesn't seem to make sense to do this IMO. The little bit you'd get into the battery wouldn't really do much. A slow charge is the best.

[berke99]

Why not just buy a second deep cycle battery. This should eliminate your problem and avoid the other hassles.

[H20fowlr]

Well, if you use your vehicle, the alternator is already producing DC, and it isn't stressing it any more than when your battery is low on your vehicle. You would have to figure our how much gas your vehicle uses at idle, how many amps your alternator will put out and then you can figure an approx cost. Then weigh this against 1) another Deep Cycle, 2) a generator, 3) you solar cells

If I'm in the middle of nowhere and no extra battery or Gen, I'm using my truck.

Just my .02.

[icechipper]

How about a generator from Fleet F, they have a generator similar to the Honda at 1/4 the price on sale, that has 120V and 12V DC output. You could use it to charge your batteries and also run a few things around the house if the power was out. BTW they are pretty quiet to run, just not a quite as the Honda, but when you can buy 4 for the price of the same Honda, plus have 4 years of warranty on top of it it makes sense.

[Surface Tension]

Power inverter wouldn't be the way to go. Charging off your vehicle is going to burn a lot of gas. An alternator is used replenish what it took to start your vehicle not for charging dead batteries. Best way to charge your deep cycle battery is at home on a charger intended for deep cycle batteries.

A small generator would be a better alternative but then you get to listen to it run, more stuff to haul with you and it'll take a long time to charge. IMO the best solution is buy another deep cycle battery.

[Feldy]

Has anyone tried the solar chargers with any luck?

[Whoaru99]

Has anyone tried the solar chargers with any luck?

Yeah, solar chargers work - one of two ways.

Spend lots of money or spend less and plan on having lots of sunny days and a long time to git 'er done.

[Giant_Jackpot]

I called Pro-Mariner about this the other day ad they said it will work. The big question is can your motor’s charging system keep up? If you have a 2 bank charger with 10 amps per bank that is 20 amps total. The power inverter is going to have some losses converting the 12 volts from your motor’s charging system to AC so as a guess I would say you are going to need 25 amps out of your motor’s charging system or battery. It won’t take long to kill your starter battery at that rate. Not all outboards can handle this but check your owner’s manual for the output rating of the charging system. If you are going to use an inverter, the tech at Pro-Mariner said a good rule of thumb is to buy twice as many watts as you need. In the above example, 20 amps at 12 volts is 240 watts. I bought the 600 watt model to see how well this will work. I plan on using it only when on long runs and I know I will never get a full charge on the trolling batteries but I figure if it gets me and extra day or two of use I will be happy.

[Whoaru99]

Why don't you just connect your trolling batteries to an onboard charger system that is intended to work off the boat's alternator?

In the easiest case, just connect the trolling batteries to the charging system with a switch so you can charge or not charge.

It makes no sense to go 12V>inverter>battery charger>12V.

All you've done is add more conversion losses.

[Giant_Jackpot]

I want the inverter so I can charge all the other stuff I seem to bring along these days. Cell phone, camera, portable XM, probably even the wife's hair dryer......

[Whoaru99]

Well...you didn't tell us of those ulterior motives before.

Oh, BTW, the last hair drier I looked at was like 1200 or 1500 watts. How big of an inverter did you get?

[Giant_Jackpot]

600 watts on purpose. No way am I going to power a hair dryer while camping. It just ain't right! The 150 hp "hair dryer" on the back of the boat will have to suffice. Full throttle for 2 minutes and it's a done deal.