Are batteries charged while running outboard?

[Alumahollic]

I have two batteries on board my boat. My trolling motor is attached to both batteries in a 24volt fashion. I have the outboard, and most of the accessory switches wired to one of the batteries that I consider my "starting" battery. My question is whether or not my 90hp yamaha 2-stroke is charging this battery when it is running. Do outboards have an alternator like cars?

And, if so, since my batteries are wired together will this charge trickle over to my other battery that my 12V spotlights are wired too?

I'd like to know if either of the batteries are receiving charge so i'll know which ones are best to plug my nighttime spotlights into when running at night.

 

[Splat]

Re: Are batteries charged while running outboard?

Couple of things here.

We need to know if your outboard has a alternator, or stator charging system.

The amount of charge being placed back into the batteries while your underway is prolly pretty minimal. Most charging systems don't put out enough amperage to make a huge difference, especially on a 24v system.

Will the voltage trickle over to the other? Not if the batteries are wired in series. It will only charge the battery it's attached too. You could attach the batteries both in paralelle and series at the same time, but once again the amount of charge amperage will be nill.

Lastly you should NOT be using spotlights while underway at night. Turn off all lights except for your nav and anchor lights and navigate by the moon, and ambient light. Spot lights blind other boaters, and create "night tunnel vision" in that your eyes will adjust to the spotlight and anything not totally illuminated you will become blind too.

The moon shining on the water I'll take any night over a spotlight.

Bill

 

[Silvertip]

Re: Are batteries charged while running outboard?

You cannot wire batteries in series and parallel at the same time. It's one or the other. If you have a 24 volt troller, the batteries need to be in series. The engine has a 12 volt alternator and cannot be placed across the both batteries. You should also disconnect the starting battery from the 24 volt system as sooner or later you will find yourself dead in the water. Run the troller on two 12 volt batteries in series. Run the engine off its own battery. Add a dual output on-board charger and charge the troller batteries from AC power at the dock. The engine does not have a large enough alternator to charge two batteries much less three.

 

[4JawChuck]

Re: Are batteries charged while running outboard?

Without a VSR charge controller you will only be charging the 12VDC connected battery, the second battery is connected in 24VDC parallel and does not receive a charge while the engine is running.

Most folks use some sort of VSR (voltage sensitive relay) or ACR (automatic charge controller) to distribute the charge amongst their batteries while the motor is running.

I use a BEP Marine VSR/distribution switch, it works great and really extends the trolling time if I am out camping and don't have access to a plug in to charge the bats. There are many manufacturers of these products and many choices out there.

http://www.bepmarine.com/Clusters-180.html \

This is the one I have on my dual battery setup but I run a 12VDC trolling motor off the second bat.

http://www.bepmarine.com/Single-Engine%2C-Two-Battery-Banks-180-1460.html

As for connecting your 12VDC electric loads, mine all run off my starting battery so when the motor is running the motor sees the load and charges accordingly. You can run them off the second battery but most manufacturers do not recommend running sensitive electronics from the second battery due to the interference and sudden switching that occurs when the VSR/ACR cuts in to charge the second battery.

Standard hookup is;

All electric loads off main battery and only the trolling motor gets hooked up to the second bat for 24VDC operation, make sure you buy the right ACR/VSR for your configuration of 12/24VDC hookup. With the BEP setup it doesn't matter but others might make a distinction.

For the ultimate in flexibility and safety a second battery added to your boat to run the trolling motor in 24VDC is the ideal setup, this way you always have a fully charged battery to start the motor and you can utilize the 24VDC parallel battery set to full capacity without fear of not being able to start the motor.

Your motor likely only has a stator charging circuit with an under 20A capacity (you need a much larger motor to get a real alternator), my 90HP Merc only has a 16A capacity stator. I find 16A enough to charge my bats and keep them topped up but serious daily use of the trolling motor would eventually run the second bat down requiring charging overnight to restore it to full capacity. 3 days of camping with 45 minute runs back to camp is enough to keep the first starter bat charged for the trip but the second bat needs charging when I get home.

If you are running spotlights all the time cut your trolling motor run times in half to get a realistic figure of how long you can run them. BTW the other posters are right, spotlights are for sitting fishing...not running down the river/lake/ocean at speed.

Good luck.

 

[Alumahollic]

Re: Are batteries charged while running outboard?

Guys thanks for the responses. All good advice. I definitely need to figure out a way to make some room for a dedicated starting battery. Just hate adding that much weight to the back of the boat and theres really now where else to put them.

Also, I agree about spotlights and nightime running. I should have clarified. I use these spotlights when idling through bayous and creeks here in south louisiana at night to look for frogs etc on the bank. We idle for several hours with spotlights running constantly. Never use the spotlights while actually running. As most people would agree, you can actually see better with no lights at night time.

 

[4JawChuck]

Re: Are batteries charged while running outboard?

Don't forget your starter bat can be smaller than your trolling bats, Merc recommends a 400AH battery as a minimum size for starting my 90HP 2 stroke. You also don't need a deep cycle for this chore.

 

[gepicou]

Re: Are batteries charged while running outboard?

If you want to solve your weight problem. Go to a 12 volt trolling motor and add the onboard charging system and keep both batteries hot. One dedicated to your trolling motor and the other dedicated to your starting battery. I hope this helps.

 

[Bob_VT]

Re: Are batteries charged while running outboard?

BEP products are sold by iboats http://www.iboats.com/Marine_Batter...5575854--**********.150883881--view_id.216579

 

[trendsetter240]

Re: Are batteries charged while running outboard?

Merc recommends a 400AH battery as a minimum size for starting my 90HP 2 stroke.

I think you meant 400CCA (cold cranking amps) battery. A 400AH (Amp Hour) battery would be a massive deep cycle battery.

 

[HappierWet]

Re: Are batteries charged while running outboard?

You cannot wire batteries in series and parallel at the same time. It's one or the other. QUOTE]

Thanks for clarifying. Before I read your response I was sitting drawing diode circuits trying to figure it out.

 

[4JawChuck]

Re: Are batteries charged while running outboard?

I think you meant 400CCA (cold cranking amps) battery. A 400AH (Amp Hour) battery would be a massive deep cycle battery.

Whoops, yes I meant CCA not AH...it was a late night what can I say.