Battery charger recommendation???
 

The Guest 2610W (10 amp) charger that was on my boat when I got it seems to be dead (red light on constantly and the shop that did some other diagnosis says its bad). I have two Optima batteries in the boat and hear that their life is shortened if you charge them at too high of amperage.

Is 10 amps too much? What charger should I buy?

Thanks - Scott

i like those little 10 dollar ones from harbor freight. got one on my tractor, trencher, scallop boat, & V. will not charge a dead battery, but works well as a trickle charger

Anything over one amp will eventually shorten the life of a battery if left on for too long a time. You can use a shop charger @75 amps or a home unit @ 10-20 amps. It really makes no difference except for the length of time it will take to charge the battery. The damage is done after the battery is fully charged and you continue to try and pump juice into it.

What you want is a battery charger that has a tapering charge that then switches over to a float charger. A tapering charger will decrease the amperage as your battery gets full, and once it's full it will then switch to a float charger that will constantly monitor your battery and pump in a very small amount (typically 500ma) of electricity if your battery looses some of it's charge from sitting.

for what a proper charger would cost, you could buy at least two new battereis. I'd just get another guest and put it on a timer, let it charge for 15 minutes a day, that should keep your batteries more than ready. If you know you're going out hte next day, let it charge for a while longer. if that won't keep the batteries up, you have a drain or a battery issue

or crank the boats engine and let her run for 15-20 minutes every week or two.

Bradford brings up the second issue. The shop says my alternator is only charging @ 12.1 to 12.2 volts. It seems to me that's enough to keep the batteries from draining while I'm running, but not enough to charge them up. It's the Mercruiser 170 (I think that's pretty much exactly the same thing as a 470). It has the alternator that's integral with the crank pulley.

A couple of years ago I had to rebuild the water pump, which is buried deep and needed to pull the crank pulley. The magnets were all loose, it was full of rust and there was some corrosion on the windings. It had eaten probably 1/4 of the way through the wire in a few places. I cleaned out the corrosion and varnished the coils thoroughly. I think the dash gauge was reading 13+ volts when I fired it up, but can't swear to it. Thanks again to Spare for getting me through that project with a little bit of sanity left.

I'll need to go to the manual - I don't even know where the voltage regulator is located. Any diagnostic comments would be appreciated.

Spare - the Guest chargers say they drop off to a float charge after the batteries are charged up - shouldn't I be able to leave that on all the time? Destroyer comments that the 10 amp charge doesn't hurt the battery if it not left on too long.

I cooked a couple of batterys in mine by over charging!! Thought my sears garage charger was great till i learned it does not shut off, charged them babys for 4 days!! when i went out they were boiling! now it has a timer on it!

some of the newer chargers will go into a float charge, they should be OK, I'd still put it on a timer just to make sure. The voltage regulator is located on the port side of the engine, just follow the water hose from the water pump(regulator is water cooled). Pull the two yellow wires from the stator and put an ohm meter on them, if its open, your stator is bad. I'll see if I can dig up the trouble shooting chart for the regulator(been while). If you end up just needing a balancer, I have a brand new one. Odds are you will need a balancer, startor and regulator so you're better off doing the alternator conversion

If you are going to charge your batteries on a regular charger than by all means get a Battery hydrometer. (it looks like a turkey baster with a float inside of it). Open the caps on the batteries and suck out some acid into the tester until the float inside just starts to float. Read the color chart on the float where the fluid is and it will tell you how much your battery is charged. Shut off your charger once the float says the battery is charged and you'll have no problems using any kind of charger. Just remember that battery acid will eat your pants for lunch if you get any of it on them, so be careful and ALWAYS wear safety goggles.

For general info, I use a shop charger that charges my batteries @ 12 amps, and it has a timer built in so I never overcharge them.

If your alternator is only putting out 12.2 it's shot, that number should be over 14. A fully charged battery is about 12.7 volts, the charge has to be above that or no go.

Thanks for the responses - I just spent a bunch of $ getting a new kicker motor, so I'm not excited about spending on a new alternator but I need the batteries in good shape - planning to start hitting the ocean and don't need any problems.

Spare - did you find the trouble shooting chart for the regulator? I do have the Merc factory shop manual but haven't had time to dig into it. About what is a reasonable cost for a kit, if I need to go that way and can I buy it from you and get it drop shipped to me on the left coast?

I'm with Garbubba, 12.2 is gonna leave you stranded. Check the voltage at the batteries with the engine running, don't trust your dash gauge. A good charging system is money in the bank in my opinion.

I agree - stranded is in a car by the road - dead engine in boat is being carried by the current or blown by the wind toward the rocks. Just hoping I can find and fix the problem without having to buy all new, however unlikely that is.

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Usually I do a visual on the balancer. Look to see if there are magnet pieces or whats left of the stator laying around the front of the engine. If the balancer is bad, it usually takes the stator out, if the stator shorts, it fries the regulator. Its been a while since I worked on one, but it used to be $200 per item(balancer, stator, regulator). If its just the regulator, get the CDI brand.

The best charger I still have my son took out of the garbage in Atlantic highlands about 20 years ago, I changed the clips and been using it ever since! Really. It has 2 settings. 2 or 6 amps and 6 or 12 volts. I keep it on 12 volts and 2 amps and use that to charge and maintain my battery's. The only thing that just broke the year is the meter to tell you what it's putting out so I use a multimeter to check it. Still works great after 20 years and might even be longer that that. And cost me nothing. Just two clips so I wouldn't get anything to complicated just a reg charger with different settings will work fine. That's what I would get

That's funny, because I have a backup charger with just those settings. Made by Schumacher I think. Came out of my dad's cellar when he passed away, but that thing is at least 20 years old... (more like 30-40) and it still works when I plug it in.... and yes, the plastic cover to the meter broke last year. I taped a piece of Lexan plastic over the meter to protect it. Just gotta remember that even @ 2 amps you can cook a battery. So I set my wife"s cooking timer and check the battery every 2 hours.

As for the alternator on the motor Id change ot over to a one wire external marine charger that mounts over the water pump and runs with a belt. I bought a new one for 60.00 in the box. Works great! I put my trusty old Shumacher 2/10 amp charger on my batteries about once a month for a couple days on each battery. It charges them up and cuts off automatically.

cfelton, where did you get a marine alternator for $60? I'm seeing kits for $250 - $600.

Spare, thanks for the manual - I'll dig into it and see what I can find.

Had to laugh reading the shop battery charger comments - we could start a historic charger website. I've had a smart charger for a few years that charges at 2, 6 or 12 amps and automatically slows down and stops and an old one that was my dad's (he'd be 104 if he were still among us). I think it's Shauer brand - no meter or anything - if it's humming, it's working, if you forget it and leave it on, you buy a new battery.

Destroyer, these are Optima batteries (the kind that don't have liquid acid). They can't be checked with a hydrometer (www.optimabatteries.com). Looking for an onboard charger so I can just plug the boat in when it's sitting (which is a lot), charge the batteries up if needed and maintain them, I heard that charging at higher amperage shortens the battery life. It's a mystery to me but I want to make the right choice when I replace the Guest 10 amp onboard charger that's no longer working on the boat - the technology is definitely above my pay grade. Reading on their website, I don't see the charging amperage being a problem, but I value the wisdom and experience here so I'm picking our collective brain.

Hey Scook, look on Amazon. I just saw a 110 amp, one wire Delco alternator for 65.67 from Rareelectrical. I used a long bolt that went right over the front motor mount into an existing hole in the head and you can make a top bracket for the top mount hole. Look at my gallery pics, maybe you can see it. If you need any measurements let me know, Ill be home for a few more days, be glad to help you.

power steering pump may get in your way.Keep in mind 1 wire alternators don't charge till you get them over about 1500 rpm, if you do a lot of trolling/low speed idling, you may have issues

It is a Schumacher. That's funny. Still works. H

Spare is right, I have to give it a little speed to make it start charging first then it usually works well.

It was a happy thought, getting by for less than a hundred bucks plus a little time in the shop, but lots of my time is spent at a slow troll for Salmon, so I'd probably better stay with a conventional setup.

Now for the alternator
 

Got a Marinco 10 amp onboard charger to charge and maintain the batteries, now I need to take care of the alternator.

The stator is shorted to ground. It tested that way on the engine and tested the same on the bench (.2 ohms either lead to ground). The regulator seemed to test OK with partial diagnosis but the body is cracked and I don't trust it - time for an external alternator.

I don't have time right now for fabricating anything in the shop so will need a kit. The question is whether a one wire type will work for my use.

Earlier in the thread I learned that the one wire doesn't charge until RPM's reach 1500. Does it quit charging when you drop below 1500 without shutting down the engine? I do a lot of slow trolling but always spend several minutes running at around 3000 RPM getting to where we fish and getting back to the ramp.

I need some education and need to get the boat going - the Spring Salmon are starting to run
up the river. I appreciate your help.

Spareparts - if you see this, please check your PM's.

A standard GM 10 SI will charge once it hits roughly 1500RPM's, and will continue to charge until you shut it off. A true 1 wire will begin charging at idle as they have a different regulator in them. Also keep in mind that teh charge sense wire for a GM 10 SI should NOT be wired directly to the ignition wire. A GM 10 SI can backfeed enough power to keep the igntion wire powered with the key off. I hate putting in a new alternator and having problems shutting them off after the install.

Thanks Ferm - how do I know I'm getting a true one wire and where would you go for the whole kit, including what's needed to hang it on my Mercruiser 170?