Help with battries

[Dustin_S]

I have 2 battries I use for trolling.
I have talk with many and they tell me that the best charge to put into these batteries is 2 amp.

But the battries are taking for ever to charge. about 2 1/2 days now and still are not full.

I have read some threads here that say you should charge up as a fast as you can. Now why am i being told to charge at 2 amps and that 10 amp can ruin a battery?

Can you guys help me? I would rather talk with other boaters who have experinced this first hand.


Dustin

 

[DRIFTER_016]

Re: Help with battries

The best thing to do is use a fully automatic charger as it will decide how much juice the batter needs. The onbord chargers for multiple batteries are the easiest as you just plug in your boat when you get home and unplug it when you're ready to hit the lake.
I have 2 trolling motor batteries and a starting battery and use a tripple output 10 amp per bank charger similar to this:

http://www.iboats.com/GUEST_Triple_...13908634--**********.436821363--view_id.38110

 

[Barnacle_Bill]

Re: Help with battries

2 amps is normally used for a maintence mode or a very small battery like in a lawn mower or motorcycle. Use 10 until they are charged. You might consider getting an on-board charger. Plug it in and forget it until the next time to go.

 

[Dustin_S]

Re: Help with battries

Thanks Guys for helping.

I appricate the help alot!

Have a wonderful day!

 

[Boatist]

Re: Help with battries

Higher amp charger will not affect your batteries if it is a smart charger. Useing a low amp charger just means your battery is in a discharged state longer and more damage is done.

I charge both my batteries with a 65 amp alternator thru a battery isolator and have not had a battery that did not last at least 6 years. Charging at home I use one of three charger the smallest being a 10 amp automatic charger. Largest being a 35 amp smart charger that will automatily step down to 2 amps before shutting off.

If you have a large trolling motor battery that get discharged 50 percent or more with use then I would get at least a 15 amp smart or auto charger. A 10 amp charger will not fully charge your large group 27 or 31 battery over night if your going to fish the next day. Not fully charging your batteries is a battery killer.
Also 2 amp trickel charger are battery killer, first they take too long to charge so your battery is in a state that causes damage for a long time. Second they have no regulation so they badly overcharge unless you watch it closely.

Low amp battery battery maintainers are smart charger and will not over charge. Good for off season storage but not good to recharge after use as take too long.

 

[199675hpforce]

Re: Help with battries

Reason for 2amps, heat is the enemy of batteries, higher the amps higher the heat. However discharged state is also an enemy of lead acid batteries. I charge mine with 6amps its not an automatic guess im cheap lol thanks walmart. Mine will do 6volt charge, 12volt at 2amps,or 6amps. I also charge my batteries out of the boat outside in fresh air. Boats would be bombs waiting to go off with fuel onboard.

 

[DHag]

Re: Help with battries

I have the exact same issue, so this thread is very timely. I have a 10-amp smart charger running on just one of my two trolling motor batteris right now. I worked them hard yesterday. It's been on all night and it's still pushing 8 amps. So, I'll be patient for now, and look into getting an on-board charger.

But this post raises another question I have--

I charge both my batteries with a 65 amp alternator thru a battery isolator....

This sounds like you're using the tow vehicle to charge your batteries. Is that right?

I have considered using my Tahoe's trailer brake circuit to charge the trolling batteries while driving. I'm planning to add brakes to the trailer, so I'll be getting the brake controller that enables the 12v circuit to the 7-wire trailer connector.

In the boat (17' Champion bass boat), the 24 volt plug for the trolling motor has a 3-position switch, "24V," "12V" and "Charge 2-12V." I tested, and I can charge both batteries through this plug on that last switch setting.

So, can I just run a pair of 10 gauge wires (8 gauge?, hot and ground) from the 7-wire plug on the truck up to the motor plug on the boat, and charge the trolling batteries while driving? Would I need to include an isolator in that circuit?

 

[Silvertip]

Re: Help with battries

Your plan has some flaws. The brake controller mounts inside the truck at the dash. The output of the brake controller feeds the brake circuit on the truck trailer connector ONLY when you step on the brake. So wiring a charging system from that system would not work. You would be far better off running a heavy +12V and Ground wire directly from the truck battery to a separate connector at the back of the truck. Plug your charging harness into that. Unless your truck has an ACCESSORY terminal that is factory wired with a heavy gauge wire, none of the other wires would be heavy enough to carry the charging current you need for a parallel system.

 

[DHag]

Re: Help with battries

That's the stuff I needed to know.

I had the impression that the 12V connection was always hot, and the brake controller worked on the ground side. But I haven't looked into it very deeply yet, so I could definitely be wrong.

Could be a good excuse to install that pair of battery jumper plugs (one front, one rear) that I've been thinking about.

Would I need an isolator with this setup?

Thanks a bunch!

 

[Boatist]

Re: Help with battries

I charge both batteries form the 65 amp alternator on my 140 Hp I/O.

I can also charge from my 100 amp alternator in my truck. I ran a 8 guage wire from the truck battery thru a 20 amp auto reset circuit breaker to my 7 wire trailer plug. Also had a 8 guage ground wire from the engine block back to another wire on the 7 wire trailer plug.
From the trailer plug it goes the another plug on the front of the trailer near the wench. Then have a wire that goes from the plug near the wench to a plug on the bow of the boat. From the boat goes back to same battery isolator I use for my engine and charges both batteries. I hardly ever make the connection from the trailer to the boat but can anytime I need to in about 3 seconds.

The thing is either alternator put out about 14.7 volts and at that point the battery will determine how much current it will take. If the battery is discharged then it could take 20 amps or more but as the battery charges the voltage will remain the same but the current the battery will take will drop to 0 amps. So you can not charge the deep cycle in the 30 minutes it took to get back to the dock or the 45 minutes it takes to get home even with a 100 amp alternator.

The same is true for battery charger except if the battery is discharged and you hook up a 2 or 6 amp charger to charge 2 batteries the charger will not be able to supply enough current to hold the voltage at 14 .7 volts until the battery has reached a charge nearly full. A higher amp Smart or Auto charger will allow the battery to charge faster but still regulate the max voltage at about 14.4 volts or a little higher in maintenance free mode.

My buddys bass boat has a 175 outboard with a 8 amp charger so he only charges the starting battery.
I have fished a lot of Bass Tournments where on Saturday we pre fished until about 1400. Then went home and hooked up the 15 amp charger and let charge all night or until about 3 am when must get headed to the Lake for the dawn blast off. Even with 15 amps a group 27 battery has not fully charged in the 12 hours the charger was hooked up. It will have a descent charge and have tapered down to 3 or 4 amps but several hours from reaching full charge. If your charging two group 27 or 31 then it not even close to being fully charged. I know not everyone get up at 3 AM to make sure they get to the lake and get the pre launch boat inspection done and get launched before your blast off time. My point is it takes time to fully charge a large battery ever with a 15 amp charger. If your useing 2 amps even in 24 Hours is not going to be fully charged.

The other thing about small unregulated charger like 2 amp or 6 amp non automatic is they will over charge if you do not watch it closely. Instead of the voltage staying at 14 .7 volts when the battery is charged it may keep climing to 18 volts or more and overcharge the battery. You can get some pretty cheap automatic charges at walmart or here at Iboats that do a great job and are not over priced.

All the onboard chargers I have seen are also very good but high priced.

 

[DHag]

Re: Help with battries

Thanks for that info. I had the idea that I could fully charge the two trolling batteries from the truck in the drives to and from the lakes. I guess that's not the case.

I don't do tournaments, and I only get out about once a week, so an onboard would do the trick, even if I do get up at 3 am to start fishing at sunrise.

I just got back on the water between doing repairs and waiting for the floods to drain here in Iowa. My batteries had sat for a long time. I thought I had them sufficiently charged, but after only about 2 hours running time, my motor's charge indicator was reading "recharge."

My 10-amp smart charger was on Battery 1 for about 40 hours before it finally indicated "FUL." It has been on Battery 2 for almost that long, and it is still indicating 2.5 amps.

Too bad the onboard chargers cost so much. That would definitely be the solution for me.

 

[Boatist]

Re: Help with battries

You can get a higher amp charger at walmart pretty cheap. They carry two brands Black Decker that is a Vector's brand but Black and Decker bought and now market under there name. The Other brand is Schumacher.

Both I have used and think they are good automatic chargers. The black and decker has models up to 35 amps and the Schumacher has models up to 25 amps. Each of the models you can step down to 2 amps if you want to. The Black and decker will automaticly step down as it charges. The Schumacher I recall stays in the mode you start in but is regulated and will not over charge. Both brands do a good job of replacing the bulk charge quickly then then float an equalize phases take some time. Just no way to finish the charge fast without the chance of over charging.

Sorry to here of all the flooding back there and the bad weather.

One thing to remember is in summer need to charge the bateries one time a month weather you use the battery or not. All batteries self discharge and the warmer it is the faster they do. In winter also need to charge but can get away with every other month or in really cold maybe 3 months.