Regulator for charger voltage

**Chaz** · 12-14-2018, 09:21 AM

I have a pair of Odyssey 925 batteries in my boat. They never really had the power I was led to believe they should have. Still under wty and two years old they have 10.3 and 10.7 volts . Which they both dropped to from 12.5 and 12.7 two weeks before.
I called the place where I bought them and asked for an RMA number to send them in for replacements.
At 60 years old I was told I don't know how to charge a battery.
( I knew I should have went to NAPA or Walmart ... No question replacement )
I said : the boat has two 65 amp chargers built in called alternators and I own a 3 amp trickle charger as well as a Schumacher 1/6/10/50 amp charger.
I was told that I have been undercharging it . SEEMED HAPPY FOR TWO YEARS

OK , now that it has been discharged and undercharged they need a high 8-12 amp charge

to decalcify the plates

that is limited to 14.7 volts to keep the battery from gassing. Naturally, my Schumacher is not on the approved list because the 10 amp mode will charge at 15.5 volts.
I don't mind buying a $90 charger. I don't want to buy a $90 charger for a set of batterys that I don't trust. Or if I "knock the calcium off" will float off the bottom and short out the plates.
I'd rather , build a simple regulator > seen Youtube lightbulbs , circuit boards etc that will eat up 1 volt.
So I can run my charger on 10 amps / 14.5 volts without buying another charger .. idea's ... ?

**XstreamVking** · 12-14-2018, 10:33 AM

I have ATV's with very small charging systems on them with the 560 oddesseys in them. I use the winches some but have never charged them at all. 2 yrs old. They rest at near 13v. Same for my 1200's in my flats boat, run them down to 1/2 with the troll mtr. and charge them back up with a 10a total built in guest charger. So 5a each! They also rest near 13v. Last set (2 for 24v) lasted 12 yrs. I think they are trying to get out of the warranty by saying you didn't use their expensive charger. What they are saying does not add up to real world use.

**Chaz** · 12-15-2018, 12:02 AM

I never had a problem if the boat sat for a week or two. If it was going to sit for a month, I'd put the 3 amp charger on them, rotating every couple of days.
Like any other battery that doesn't have a real hot charge, they would start the motors up and the alternators would bring them up to where they would never be a concern. They were never the kind of powerhouse that you'd think was going to throw the starter off the block and out the side of the cowling if you weren't careful, but never a concern.
Lets see, same motors, same starters, same charger, same alternators, same batteries. Two years later ... rruuu ... clickkkkkkkk Can't be the batteries ..

Spoke to an electrical engineer friend today. He agrees new-teck AGM charger is best for these new teck batteries. So he's making me a Zener diode type regulator to dump off a volt so I can have a new teck charger .. just like a 1960's Triumph Bonnyville had for a regulator from the prince of darkness ...

In the mean time, I gotz three new Wally word group 24's in the motorhome. I'll put two in the boat. If I got time, I'll put one of them red POS's in my truck and see how many high volume shopping locations it will get me stuck at around town. I might be too stupid to know how to charge a ******* battery, but I dayum sure know how to post a Youtube video ..

**baja200merk** · 12-15-2018, 09:51 AM

My optima is 4yrs old and has been 10ft under water for a few hrs 3 yrs ago, i have never charged it once still works fine.

**Dave S** · 12-15-2018, 02:21 PM

HeeHee.... Gota.... pullstart.... dave S out heer.... HeHee......Thubbbs up.....

**Tom Foley** · 12-15-2018, 03:50 PM

Originally Posted by baja200merk

My optima is 4yrs old and has been 10ft under water for a few hrs 3 yrs ago, i have never charged it once still works fine.

It's gonna bite soon !!

**Dave S** · 12-16-2018, 12:32 AM

Got a Dodge Magnum SRT .... allways dead battery...went thru many bat.... just dis.. nect....

**nitro_rat** · 12-16-2018, 07:43 AM

I have a cheap Craftsman charger I picked up at a K-Mart when I was traveling several years ago. It has an AGM setting on it. 2amp, 10amp and 50amp “jump start” modes. It was significantly cheaper than $90 IIRC.

I had some Exide spiral wound AGM’s on my Suburban for probably 8 years. When they finally died they were DEAD. I have a blue top Optima in the boat that wasn’t new when I got it several years ago and it’s still going strong. I do pull it and charge it over the winter just because it’s off.

I think it worked so well on the boat because I was running it with 9amp electrics and a Holley electric pump. The pump soaked up most or all of the stator output so that it never reaches an “overcharge” situation that makes a conventional battery a better choice in most cases.

**baja200merk** · 12-16-2018, 11:23 AM

Originally Posted by Tom Foley

It's gonna bite soon !!

It’s the one Beef had in the ally that he gave u on the Suwannee and drove home with no battery

if it fails I’ll pull start it

**Tom Foley** · 12-16-2018, 02:45 PM

Originally Posted by baja200merk

It’s the one Beef had in the ally that he gave u on the Suwannee and drove home with no battery

if it fails I’ll pull start it

I gotta see that !

**baja200merk** · 12-16-2018, 03:17 PM

Originally Posted by Tom Foley

I gotta see that !

From experience a Ski rope works best. I’ll video it next time

**nitro_rat** · 12-16-2018, 03:30 PM

I tried to pull start mine once. It was heat soaked and wouldn’t bust off. It was a bear to turn over. I used the “emergency” rope in the cowling. I guess I’ll use the ski rope next time!

**Chaz** · 12-17-2018, 08:43 PM

Originally Posted by nitro_rat

I have a cheap Craftsman charger I picked up at a K-Mart when I was traveling several years ago. It has an AGM setting on it. 2amp, 10amp and 50amp “jump start” modes. It was significantly cheaper than $90 IIRC.

I had some Exide spiral wound AGM’s on my Suburban for probably 8 years. When they finally died they were DEAD. I have a blue top Optima in the boat that wasn’t new when I got it several years ago and it’s still going strong. I do pull it and charge it over the winter just because it’s off.

I think it worked so well on the boat because I was running it with 9amp electrics and a Holley electric pump. The pump soaked up most or all of the stator output so that it never reaches an “overcharge” situation that makes a conventional battery a better choice in most cases.

I've had parts countermen tell me " you shouldn't put these batteries in boats. I tell them spell-it-wit-me-naw .. M-A-Ra-I-N-E

Naw, is we gotta use it in a sen-tence ?
I would hope that a conventional lead/acid "marine" grade battery would have it's plates mounted a little stronger and maybe it's vent system routed so it didn't pizz every time it got jolted or went over a wave. But all they really seem to have is a couple of 5/16" studs sticking up next to the std lugs. I guess the good thing about them is that when they do take a leak all over the inside of your boat , you can pop the caps off and refill it ...

None of the AGM compliant chargers put out over 14.7 volts in that mode. They don't seem to care if you have a 100 amp alternator, just as long as the battery never sees 15 volts . I think it's a B.S. kind of way of worming out of WTY . 90% of the chargers out there in "John Q public's garage" are not meant for AGM batteries, yet the car or truck in the driveway now comes with a " maintenance free battery".
According to BatteryMart.com when your 3 amp digital charger says full .. it's not charged.

OK ... they need to be "rejuvenated" and have the cells "equalized".
This is done by hitting them with 12 amps / 14.7 volts for 10 hours with the magic charger. This seems more like a trick to get them thru wty than anything else. Bunch of ******* fish scales floatin around on the battery floor waitin to short out the plates ...

baja200merk

Originally Posted by Tom Foley
It's gonna bite soon !!

It’s the one Beef had in the ally that he gave u on the Suwannee and drove home with no battery

Kev,

Them Merc 3.0L alternator's are so sensitive, if you move the Perco switch while the engine is runnin. It "will" fry the circuit board in the regulator ...... PooF

**nitro_rat** · 12-17-2018, 09:07 PM

I wouldn't drop the coin for another optima but there are other agm's out there that aren't so rediculously priced. I haven't had problems with them.

**powerabout** · 12-17-2018, 10:09 PM

Check if your charger has the rejunenate process that actually hits it with ac.
Those big old forklift chargers have had it for years.
Definately works on lead acid stuff