Batteries And Chargers

[jFlips706]

I own a small aluminum boat currently powered only by a trolling motor on the bow. I am thinking of buying an outboard and using it along with an onboard charger to charge my trolling motor batteries. My question is what sort of charger do I need to charge two batteries?

 

I was thinking a single bank 4 - 6 amp charger.

 

Is it that simple?

 

BTW, I'll be using somewhere between 25 and 50 hp outboard.

[slonezp]

1 bank for each battery. If you're not making any long runs, the outboard will not keep the starting battery topped off. If you're running electronics, a stereo, and/or a livewell, batteries can drain. The higher the amp rating, the quicker the charging. So a 12v trolling motor and a starting battery get a 2 bank. A 24v trolling motor and a starting battery get a 3 bank. Being assured the motor battery is charged each and every time you plug in the boat is worth the minimal cost of the extra bank. Also, they are easy to install, but follow the directions wiring the batteries. I know the last 3 bank smart charger I bought required wiring the starting battery to a designated set of leads(if that set wasn't used for a TM battery)

[Koofy Smacker]

What exactly do you mean when you say "outboard charger"?

When you get the outboard, are you going to have it hooked up to a battery? If so, it needs to be separate from the trolling motor batteries.

As for a charger, get one that has an independent output for each battery. These stay on the battery and just plug it in and go. If you get a portable single bank charger then you need to pull all the batteries and charge them one by one before you go out next which can take hours.

[Downeaster2010]

My motor charges the starting battery, and maintains it.

I purchased a Minn Kota D210 that charges 2 trolling motor batteries which are hooked up all

the time.  After a day fishing, and I get home, I just plug in an extention cord to the charger, and

wham it charges both trolling motor batteries individually at 5-6 amps, and a full charge overnight.

Charger mounts in the boat, and wiring diagram comes with the charger.  So far I like it.  I bought

it on sale from Cabelas this spring for $109.99. 

[Koofy Smacker]

My motor charges the starting battery, and maintains it.

I purchased a Minn Kota D210 that charges 2 trolling motor batteries which are hooked up all

the time.  After a day fishing, and I get home, I just plug in an extention cord to the charger, and

wham it charges both trolling motor batteries individually at 5-6 amps, and a full charge overnight.

Charger mounts in the boat, and wiring diagram comes with the charger.  So far I like it.  I bought

it on sale from Cabelas this spring for $109.99. 

If you fish electric lakes this can seriously hurt your cranking battery. Running electronics on it all day and then leaving it for a few days leaves it discharged. Do it a few times without charging after every trip can really compromise the battery. Thats why it is best to have a charger with a bank for every battery

[jFlips706]

What exactly do you mean when you say "outboard charger"?

 

Not sure where you got that, bud. But I definitely meant 'onboard' charger.

 

So I need one bank per battery. I was thinking that to hook the batteries up in parallel would allow me to charge 2 or 3 simultaneously with one bank. Guess it doesn't work that way.

 

I was hoping I would be able to do that because I thought it would divide the charging amps by the number of batteries reducing the heat generated in the cells and prolonging the life of the battery. I understand a 6 amp charge is still a pretty hot load. I wanted the charge to be something like 2-3 amps per battery. Like a trickle charge.

 

Has anyone experienced lower battery life from a 5 or 6 amp charge on a battery. Thus far all I've ever used is a trickle charge from a portable charger. 

[Downeaster2010]

I don't need a charger for my cranking battery, as my big motor does a find job, and I only have two digital sounders

hooked up.  My trolling motor is a 24 volt, and I have two new batteries.  Like I said they are hooked up to the

Minn Kota d210.  Instructions come with the charger.  I chose this one because of price.  I would have gotten the

d220 if i were on a trournament trail, because it charges both batteries at 10 amps.  MY d210 charges at 5amps,

and will fully recharge my batteries in 10 hours.  Charging to full overnight is fine with me, and the charger is $100

less than the d220.  Charging at a lower rate 5 amps will prolong the life of a deep cycle over a faster charge.  Once

charged but still plugged into house current, the charger will maintain the batteries.  Just read up on them at the

MinnKota web site.

[Jig Man]

I own a small aluminum boat currently powered only by a trolling motor on the bow. I am thinking of buying an outboard and using it along with an onboard charger to charge my trolling motor batteries. My question is what sort of charger do I need to charge two batteries?

 

I was thinking a single bank 4 - 6 amp charger.

 

Is it that simple?

 

BTW, I'll be using somewhere between 25 and 50 hp outboard.

 

Battery chargers typically start out producing the rated amps but after a while they drop down so your 4-6 amp charger might take days to recharge your batteries.  A flooded cell battery can safely take a charge up to 20% of its reserve capacity.  So even if your batteries are rated as low as 100 reserve amps you could use a 20 amp charger.

 

Personally, I wouldn't consider anything less than a 10 amp with a bank for each battery but prefer an 15 amp.

[Koofy Smacker]

The charger I am using is a Dual Pro Onboard 3 bank with 6 amps on each bank. After a full tournament day (and I ride the trolling motor a lot) it takes about 3-4 hours to recharge the batteries fully.

 

^ any modern 6 amp charger has something seriously wrong with it if it takes days to recharge. Ive ran mine down to 20 % before and it still charged in less than 10 hours.

 

 

To answer the OP's question. Yes it is possible to use one bank dedicated to two batteries in parallel however I would not recommend it. First it will take forever to charge since its essentially double the size of the battery, and second, if they are not exactly the same age and size it can overcharge one while undercharging the other.

[Jig Man]

The charger I am using is a Dual Pro Onboard 3 bank with 6 amps on each bank. After a full tournament day (and I ride the trolling motor a lot) it takes about 3-4 hours to recharge the batteries fully.

 

^ any modern 6 amp charger has something seriously wrong with it if it takes days to recharge. Ive ran mine down to 20 % before and it still charged in less than 10 hours.

 

 

To answer the OP's question. Yes it is possible to use one bank dedicated to two batteries in parallel however I would not recommend it. First it will take forever to charge since its essentially double the size of the battery, and second, if they are not exactly the same age and size it can overcharge one while undercharging the other.

That must be a humdinger of a charger.  I run a Dual Pro 3 bank with each bank 15 amps and it takes at least 7 hours to fully charge my batteries.

[Koofy Smacker]

That must be a humdinger of a charger.  I run a Dual Pro 3 bank with each bank 15 amps and it takes at least 7 hours to fully charge my batteries.

Must be I guess. Im running all 29 series batteries and after a full day on an electric only lake my batteries are basically as low as they can go. After they recharge they are each back up to 12.6v each. Longest Ive ever seen it run was 7-8 hrs and that was after they would barely turn my prop.

 

And yes I know thats horrible for the batteries

[jFlips706]

So if I end up with two trolling batteries and one cranking battery, a good way to wire it would be...

 

Both TM batteries wired in parallel circuit(positive to positive/negative to negative)

TM connected to only one battery

All Sonar and other electrical accessories connected to cranking battery

Outboard connected to cranking battery

One Bank of charger connected to each battery(I assume each bank consists of a hot and ground wire)

 

The attached provides visual reference.

[Koofy Smacker]

yes

[Sam]

And always plug in the charger when you get home and leave the charger attached to your electrical extension cord all the time the boat is not in use.

 

Just another one of the hundreds of suggestions you will receive.

[Chris at Tech]

Where are you located? I have a 2-bank MinnKota on board charger I took off my old boat that is just sitting in the garage. I'd let it go pretty reasonably but hoping to avoid shipping. Insure the chances are slim that you're nearby, but thought I'd ask

[slonezp]

So if I end up with two trolling batteries and one cranking battery, a good way to wire it would be...

 

Both TM batteries wired in parallel circuit(positive to positive/negative to negative)

TM connected to only one battery

All Sonar and other electrical accessories connected to cranking battery

Outboard connected to cranking battery

One Bank of charger connected to each battery(I assume each bank consists of a hot and ground wire)

 

The attached provides visual reference.

Only if you have a 12v motor. If you are running a 24v the TM batteries need to be run in series

[jFlips706]

Only if you have a 12v motor. If you are running a 24v the TM batteries need to be run in series

 

I do have a 12V TM. 

 

A question though.. If I have my TM batteries wired in parallel, should they still be treated as two batteries and thus need a charger bank for each battery?

[slonezp]

yes

[jFlips706]

Where are you located? I have a 2-bank MinnKota on board charger I took off my old boat that is just sitting in the garage. I'd let it go pretty reasonably but hoping to avoid shipping. Insure the chances are slim that you're nearby, but thought I'd ask

 

I actually will need a three bank charger. Thanks though.

[Optima_Jim]

Jflips706, I checked with one of our engineers on this, because I wanted to be sure. If you are running a bank of two parallel batteries to power a 12-volt trolling motor, you only need one connection from that bank back to your charger (positive from one battery, negative from the other).

 

Jim McIlvaine

eCare Manager, OPTIMA Batteries, Inc.

www.pinterest.com/optimabatteries

[slonezp]

Jflips706, I checked with one of our engineers on this, because I wanted to be sure. If you are running a bank of two parallel batteries to power a 12-volt trolling motor, you only need one connection from that bank back to your charger (positive from one battery, negative from the other).

 

Jim McIlvaine

eCare Manager, OPTIMA Batteries, Inc.

www.pinterest.com/optimabatteries

But he'll have double the charging time

[Optima_Jim]

slonezp, while it is true that connecting two batteries together in parallel will essentially create one larger battery that will take longer to charge, if you are suggesting that by individually connecting two batteries already wired together in a parallel bank to a charger, that they will somehow charge twice as fast, our engineers would be very interested in your reasoning behind that.

 

Jim McIlvaine

eCare Manager, OPTIMA Batteries, Inc.

www.pinterest.com/optimabatteries

[slonezp]

I am suggesting that having a bank for each battery is the best way to go. I'd rather him spend the few extra dollars on a charger than risk getting stranded on the water, or drive 2 hours to go fishing only to find out the boat won't crank. Been there done that ain't gonna happen again if I can help it.

[Optima_Jim]

As I re-read this thread, I think the correct answer is closer to what you had posted earlier. When I shared the diagram jFlips706 posted, it gave the appearance of a single bank charger. While connecting the batteries individually to different banks in a multibank charger will provide a faster charge, it will not be twice as fast, due to the different charge rates during different charging cycles. Our engineer did estimate it could be up to 50% faster than charging both batteries from a single bank at the same rate, depending on a variety of factors.

 

Jim McIlvaine

eCare Manager, OPTIMA Batteries, Inc.

www.pinterest.com/optimabatteries