Anyone use an onboard DC alternator charger?

[Rockin Rod]

Looking at a Stealth or the Minnkota DC alternator charger for my trolling motor batteries for when I go on long excursions up to LOW with no power. Does anyone have any experience with either?

[CAMAN]

Not sure I agree with this. In fact I have seen arguments to the exact opposite; That deep cycle batteries will last 2-3 times longer if you don't let them discharge deeply but rather keep topped off.

I'm not talking about charging a battery before it is discharged. I do it both ways and have never had an issue. I'm talking about throwing high enough amps into a battery to charge it in 10 minutes, THAT is not good for most deep cycles .

[CAMAN]

Caman is flat out wrong because he does not know how these systems work. They will not kill the batteries. Most guys get longer life out of their batteries.

And AGAIN please explain how these systems work. I asked earlier and you dodged the question.

[CaptainMusky]

And AGAIN please explain how these systems work. I asked earlier and you dodged the question.

You didnt care to know or research for yourself (because you didnt "need or want one") so I didnt dodge the question. A simple G oo g le search will tell you all you are asking.

[CaptainMusky]

They do NOT slam 50 amps into a battery regardless of what brand/unit you buy. The minn kota will put in 10 amps max per bank while the others will allow as much as the battery requires. If it wants 10 amps, they give 10 amps. If they want 15, they will give 15. If they want 2 they will give 2.

The Stay N Go alternates between the batteries every 2 minutes so they never generate heat.

These are not switching devices that basically send all current from the outboard's alternator to your battery. Each of them have some "brains" to them to only direct what the batteries call for, they just may achieve it differently.

There, is that enough info for your CAMAN?

[PropsterII]

"Not sure I agree with this. In fact I have seen arguments to the exact opposite; That deep cycle batteries will last 2-3 times longer if you don't let them discharge deeply but rather keep topped off."

Agreed. I could be wrong but I believe that was the old school of thought, that they needed to be deeply discharged each time and then slowly charged back up. The problem with deep discharge is the sulfonation that can occur. I believe with today's technology most everything I'm hearing is that not discharging so deep, and charging more often and quicker in order to keep it nearer the top of its capacity, will actually extend the life of deep cycle batteries. I'm sure someone with a much deeper understanding of this will chime in.

[h8go4s]

I did some research on this last fall. I have a single main battery and a single TM battery, so I was looking into the Minn Kota MK1 (1-bank).

The manual says this: "In order to achieve full output from the DC Alternator Charger, the minimum input from the engine alternator must be as follows:MK-1-DC: 12 amp minimum " My outboard manual (F50 Yamaha) says this: "Maximum generator output 16A."

I talked to a customer service rep at Yamaha and he said at 2-4000 rpm the generator output is 3-4 amps (vague, in my opinion), at 4500 rpm 4 amps and full output at 6000 rpm. That is what we used to call a hockey stick curve, and I'm not confident that I was getting good information. I asked if he could talk to his engineering department and get a chart or graph showing the full rpm vs. amp output for me. He said that he'd have to contact Japan for that and was unwilling to do so.

I then emailed Minn Kota customer service and got this response: "The 12 amp minimum from the alternator is required for the charger to switch over and charge to the trolling motor batteries. I am not sure what the full output of the outboard is however if it at full output at 6000rpms that is what would be needed to apply a charge to the batteries using the alternator charger. If output at 4 amps at 4500 rpm that would not meet the requirement of the charger and would not charge the batteries."

I didn't think any of that was very helpful, so I gave up. I also looked at the Yaninda battery combiner, which sounds like it would work for me, but haven't found a retailer who handles them, so I'm a little gun-shy.

http://www.yandina.com/c100InfoR3.htm

[Loon]

I know that my Mercury has a 50 amp alternator and I have the 2 - bank DC charger and the charging light is on even at idle and I rarely have to charge my trolling batteries.

I have huge AGMs and don't run the trolling motor super hard but I fish 5 times a week and figure it can't hurt to harness the otherwise wasted amperage being produced by my outboard.

My week-long trip to an island on Rainy was the original reason for the purchase but we have a nice Honda generator now so it is no longer necessary.

As satisfied as I have been with the purchase I am not 100% positive that I will put one in my next boat but that is simply because I have a nice generator now...not because the product doesn't perform as advertised.

[CaptainMusky]

Good info Loon. I am assuming you have the minnkota model correct?

[CAMAN]

Pssst....

Quote:

Always allow batteries to "cool off" after charging. The cooling time is very important because heat is generated during the recharge and discharge cycles. Without the cooling time the heat grows, accelerating grid corrosion, which is one of the major causes of battery failure.

Opportunity charging (quick charging between uses) is detrimental to battery life. While it is true that the shallower the cycle, the more cycles the battery can deliver, opportunity charging is not good because the cooling time is eliminated, shortening life. (I.e. One charge cycle per day is preferable.)

[CaptainMusky]

Cite your source.

Again, I trust someone who has actually used these systems and their experience with them then some random quote.

You obviously haven't read or comprehended the information I provided at your request.

Why don't you move on Caman since you "don't want or need one"?

[CAMAN]

You're defending these things like you own part of the company...

And you know dang well if I cited my source properly I would get a "timeout"

It came from a HSOforum called "northwest battery" and a few other sites say the same thing...

[CaptainMusky]

Whatever dude. Just move on. You cannot stand to be wrong or realize you don't know something.

Why do you care again I ask since you don't "want or need one"?

I on the other hand WILL be buying one based on feedback from others and research because I see a tremendous benefit.

You go an putt around on your ponds and plug into your 120 outlet at the end of the day. Those of us who fish in places who don't have that option look for solutions to meet a need.

[fishwater]

I'm interested in installing one on my boat, I do a lot of camping out of it. I searched through a pile of reviews of the Stealth1 dc charger and did not find one incidence of anyone having a single complaint of any kind. In all honesty, I only found one complaint for any brand, and that one is no longer available. A number of long time users of the stealth1 claim they got longer battery life, even suggesting they could use off-brand batteries with improved performance.

I think the suggestion to not "opportunity charge" is for instances where the duty cycle between discharge and charge is too continuous. Discharging, then re-charging (at a fast rate) with little downtime. I don't think any of the marine dc chargers will overheat your batteries, reducing battery life.

[CaptainMusky]

Ssshhh fish water! Don't tell caman this he won't understand and it can be our secret.

I'm impressed by the stealth1 as well but not as much on the price. Its basically double the price but maybe its worth it.

I did talk with the guy in charge at stayncharge earlier this week. Great guy and really helpful. Still not sure which way to go but I have to do something along with replacing ALL my batteries after only 3 years because they are shot. One won't take a charge and the others are acting up as well.this is the result of religiously using an AC charger after every use and monitoring levels etc.

There is no way my battery life decreases when I get one.

[Rockin Rod]

Of the available options out there, I've narrowed it down to the minnkota or the Stealth. Leaning towards the stealth, but I'm a little intimidated about installing it versus if I go with the MK my dealer will put it in for me when my boat comes in from the factory.

Also, as part of the boat deal I worked, a minnkota precision 2-bank charger was part of the deal. Can't decide if I should leave that in or have them credit me and go with an AC/DC Stealth system.

Decisions, decisions.

[CaptainMusky]

Oh the quandary! The minnkotas precision is as good as anything out there for an AC charger. I say keep that since its included and they probably wouldn't credit you the real value of it to replace with something else.

After that get whichever DC system you like. The one thing about stealth as opposed to minn kota is you don't have to wire into factory harness with the stealth with the "purple wire". Not a major deal but if you have to do yourself it may make you uneasy.

[CAMAN]

Whatever dude. Just move on. You cannot stand to be wrong or realize you don't know something.

Why do you care again I ask since you don't "want or need one"?

I on the other hand WILL be buying one based on feedback from others and research because I see a tremendous benefit.

You go an putt around on your ponds and plug into your 120 outlet at the end of the day. Those of us who fish in places who don't have that option look for solutions to meet a need.

LOL!

And I see you aren't denying you own any stock in the company...

Opportunity charging is exactly what these things do, how long is it between you pulling the motor up and cranking up the motor? 10 seconds? It takes a heck of a lot longer than 10 seconds to cool down the internals of an 80 pound battery. Then turning off the motor and starting the trolling motor another 10 seconds maybe 30 if your slow?

[CaptainMusky]

Which company do I own stock in? Since I have mentioned at least 3 of the main players.

I get it, you cannot comprehend how these things work.I don't know how many times I can tell you that NONE of these solutions force ALL of the amperage from the outboard for you to understand OR the fact that some of these systems charge for mere minutes at a time on a single battery to eliminate any concern of heat buildup OR the fact that thousands of people use these including law enforcement, us military, coast guard etc. But I understand its "opportunity charging".

What if you pulled your motor out and then immediately plugged the ac charger in? SMH

[CAMAN]

Calm down Mr Musky...

Some people can get riled up over the most insignificant things.

Oh, and please tell me how charging a battery in 10 minutes immediately after it has been used for an hour is good for it...

Quote:

One of the systems will recharge your trolling batteries in 10 minutes for every hr you used your trolling motor on high.

And don't say "it switches back and forth" because you would need probably 40-50(maybe even more) amps to fully charge a partial battery in 5 minutes. Read between the lines of what these manufactures are saying they sound all great but when you look into it they aren't all that great for your batteries lifespan.

At this point if you REALLY needed one the Minnkota charger is probably the best as it limits the amperage. But i would still let the battery cool down before and after charging.

[CaptainMusky]

At this point I could honestly care less about what "you" would do since you have never used ANY of them to provide any factual evidence which is what was asked for by the OP.

You do understand that in a 24 volt system the amperage draw is split evenly amongst the two batteries (provided they are in equal condition)?

24 amp draw may require as few as 5 minutes to restore each battery (depending on output). I know its hard to understand for the obtuse.

[CAMAN]

Oh booohooo, someone disagrees with you. That gives you right to call them names. You know I would have given up on this thread 3 pages ago if you didn't keep calling me out. I like jabbing the bear when they start calling me names. See ya bozo!

[delcecchi]

Caman, why would a battery get hot as it is discharged? The internal resistance is quite low, much less than an ohm, as can be seen by the fact that the battery voltage doesn't drop very much as load is increased.

And likewise the overvoltage to charge a battery is only a couple volts over the 12.6 volt electrochemical voltage. So charging at 20 amps puts maybe 60 watts into that 80 pound battery. Take a long time to heat it up at that rate, and most of the heat would conduct away into the air.

So for typical trolling motor and charging currents I am skeptical of claims that heat is an issue.

[CaptainMusky]

Del don't start applying more logic with this guy. You cannot provide enough info for him to "get it" even though he "doesn't want or need one".

[CaptainMusky]

Oh booohooo

boohooo that's the best you can come up with? At least know what you are talking about if you are going to interject your opinion on something. Then and only then does your opinion matter.

[CAMAN]

Caman, why would a battery get hot as it is discharged? The internal resistance is quite low, much less than an ohm, as can be seen by the fact that the battery voltage doesn't drop very much as load is increased.

And likewise the overvoltage to charge a battery is only a couple volts over the 12.6 volt electrochemical voltage. So charging at 20 amps puts maybe 60 watts into that 80 pound battery. Take a long time to heat it up at that rate, and most of the heat would conduct away into the air.

So for typical trolling motor and charging currents I am skeptical of claims that heat is an issue.