CAT Alternators & GEL/Sealed/AGM Type Batteries

[Maybe A Dancer]

Seems like sealed gel cells are what everyone installs with a modern battery charger.

When I got my 1996 450DA it was equipped with 6 year old gel cell batteries and the factory, 1996, 60 amp battery charger which I do not believe has a battery type selector switch.

At that time there were no gel cells to be found in SW Florida, so I did the Wal Mart thing and grabbed 5 group 27 lo maintenance, old fashioned, lead acid batteries.

All 5 installed, and a year later, no issues.

This was how I handled my 10 meter for 21 years, cheap batteries that were changed out at 4 years, no matter what.

So two questions:

1) CAT power and gel/sealed/AGM/lithium/etc batteries with the correct shore powered charger - how does the vintage 1996 CAT alternator not overcharge the batteries while under power?

2) Is the 9kW genny battery charged by the shore power charger, or is it isolated, charged solely by the magneto in the genny?

BEST !

RWS

 

[dtfeld]

Edit:

I think your referring to AGM, not Gel batteries. Very similar, but AGM much more prevalent/easy to find and as of late cost effective. Gel batteries are out there, but are very expensive (relatively) and require a special charger/charge profile. I don’t see them in marine applications or at least in Sea Rays.

Per Deka charge guidelines, Deka AGMs (there are various brands names that are a similar battery) should absorb charge at 2.4V-2.43V per cell, so 14.4V for a 6 cell 12V battery. The CAT alternators are adjustable and can be adjusted to output this level and get the batteries fully charged under way, and not over charge them. I think mine are set at 14.4.

If you have a 3 bank battery charger, all 3 batteries are charged off that charger, and the newer chargers have at least 1 maybe 2 AGM presets, so they get well taken care off when running on shore power /generator.

The generator has an alternator, so the generator battery has 2 sources of charge, just like the Port/Starboard batteries. However, to my knowledge, the Westerbeke alternator output is not adjustable.

 

[ranger58sb]

Seems like sealed gel cells are what everyone installs with a modern battery charger.

I suspect that's an incorrect premise. I read about some sailors and some few trawler cruisers using gel batteries, but otherwise... not so much.

Instead, I see much more about flooded lead-acid batteries, sealed ("maintenance free") lead-acid batteries, and AGM lead-acid batteries... and in some boats, lots of more current discussion about LiFePO4 (aka LFP) lithium-based batteries.

None of those would likely be bothered by an original Cat alternator. (LFP not generally recommended as a starting battery, although there are apparently exceptions.)

Older chargers often offered only two settings, one for flooded lead-acid, and one for gel. Former setting would most likely be appropriate for AGMs (sometimes mentioned in the charger manual's fine print).

Newer chargers began offering more settings, and newest chargers now usually offer several different preset charging profiles to choose from AND the ability to just pick your exact voltages for bulk/absorption and float.

Latter gives you best capability to program in exactly what your current batteries want (per their manufacturer's recommendations). Lifeline AGMs, for example, want lower voltages than Odyssey AGMs...

-Chris

 

[Sgrochow]

RWS,

This doesn't answer your questions, just wanted to share my battery experience.

On my boat, in 2008, the previous owner installed (6) 6 volt golf cart batteries, in three battery boxes. They were the type that I had to add distilled water to a few times a year. The inverter/charger was a Prosine 2.0, Link 10. He liked to stay on the hook and use the inverter instead of the generator.

Hard to believe, but the batteries were still good in 2019. I figured at any time they would crap out and we had a long trip (Buffalo to NYC) on tap. Replaced with Interstates, $1300 total.

Prosine inverter/charger failed this summer and I replaced with a Xantrex 1800.

 

[Strecker25]

I’m still on the Walmart flooded acid plan with our 1240p promariner charger. I use 2 x group 27’s per main (deep cycle) and a single group 27 max starting for the Gen. It was around $400 to replace all 5 of them and they’re still going strong.

I’ll probably cycle them out 2 per year over the next couple years to stay ahead of any issues

 

[Maybe A Dancer]

Edit:

The CAT alternators are adjustable and can be adjusted to output this level and get the batteries fully charged under way, and not over charge them. I think mine are set at 14.4.

Any guidance on the adjustable feature?

BEST !

RWS

 

[fwebster]

Your 450DA and mine were built within a few months of each other. I had a Pronautic 60A convertor and we hanged all my batteriews to Red Top Optima AGM batteries in 1999 and never used another type of battery and she still has the last set of Optimas in her that I installed. We averaged between 48 and 60 months life span on AGM batteries during our ownership.

The Pronautic convertor was not adjustable so we just installed the AGM cells and enjoyed their life span and high CCA's.

If you or other Caterpillar owners ever need to replace alternators, The Cat remanned alternators are good but very expensive. We replaced our oem Cat 56Amp alternators with new Leece Neville- Prestolite 100amp 8MR2070TA /110-603 Prestolite alternators that cost $260ea. about 5 years ago. Again, with no adjustment needed to the Pronautic convertor .

The only other change I made was to remove the OEM belt guards. We had a discussion about this a week or so ago and I ran by my boat while we were in Florida 2 weeks ago and got a picture. You can make your own judgment as to the need for belt guards, but on the 450DA there is room between the engine to stand and work and the belt and pulley on the stbd atternator is certainly exposed and need guarding. On models narrower than the 14 ft beam on the 450, you may not need to guard the belts. Be your own judge but on the 450's you certainly do need a belt guard on the stbd side. This view is from the center of t he bilge betweem the engines looking down at the top of the stbd alternator.
i made it out of stainless steel because I had some scrap ss sheet in the scrap pile in my shop.

 

[dtfeld]

Any guidance on the adjustable feature?

BEST !

RWS

Edit: There ya go^^^^

I was under the impression that there was a potentiometer on the alternators' voltage regulator, but I have never looked into to do this or done it myself, my alternators have been bulletproof, and not needed anything (knock on wood). Maybe Frank @fwebster knows the procedure, or can elaborate.

The spec on the alternator is 14V +/- .5V so they should be quite acceptable for either a FLA or the AGM batteries. I'll have to pay attention next time, but I know mine reads in the 14.2 + range once the batteries recover from the starting process, so I would consider this the "Absorb Voltage". Regardless, they wont over-charge absent a Voltage regulator failure.

As far as the newer battery Chargers like the ProNuatic have several profiles and seem to do a very good job of maintaining a full charge on my batteries.

I'm in the process of adding battery monitors, so maybe next season I'll have some better intel for you.

 

[dtfeld]

Looking up the Alternators Frank just quoted, there looks to be a a potentiometer on the Voltage Reg, so I'm assuming this can be adjusted. I believe I already have these alternators installed, so, I'll have to look next time out. As far as how to adjust, I don't have a reference, so I'd like to learn this also.

 

[fwebster]

I don't have the adjustment details for the Prestolite alternators. I ordered the alternatrors thru the marina to get their discount. They were late arriving. We had committments in Tennessee and had to return there before the alternators arrived. The marina had 2 other Cat boats needing alternator replacements. My deal with the marina was to use my boat as a guinnea pig for new products; just get it back together and not leave it our of service without telling me. The mechanic I always used is their best and most experienced. He is fast, never makes a mess and I have never had to ask the service manager for a do-over. They put the Prestolyte alternators on my boat first to be sure the wiring was compatabe and plug and play and it was done right after I left town. I had previously replaced both dash volt meters with led digital volt meters and both showerd 14.0 volts when not under load after the Prestolite alternators were installed. I very seldom used the marina mechanics for little jobs like this but we just ran out of time and it worked out that they needed my "guinnea pig" because there were 2 other boats neededin alternators at the same time. Sorry I don't know the details…….

 

[dtfeld]

I would assume that you adjust the alternator output voltage once you have fully charged the batteries and this will give you the correct absorb voltage...probably something in the 14.2V- 14.4V range.

If adjusting under a heavy load, the voltage will be sagging down likely in the 13.8 (or lower possibly), and give a higher 9and possibly too high) voltage once the load subsides.

 

[ranger58sb]

I had a Pronautic 60A convertor ...

We averaged between 48 and 60 months life span on AGM batteries during our ownership.

The Pronautic convertor was not adjustable

We added a ProNautic 60 to our previous boat; it had 13 pre-programmed settings, plus one user programmable setting. Had to do the programming on the unit, not on the remote.

We got 11 and 12 seasons each from our banks of Odyssey Extreme AGMs in that boat.

-Chris

 

[Maybe A Dancer]

THANKS ALL !

Love the Prestolite adjustable alternator info. Thanks Frank. - I cut and pasted that into my permanent snipped info file.

IMHO, it's best to run the factory belt guard on the starboard side, however I've removed/saved the port side guard with all the spacers ty-wrapped to the correct location points on the belt guard

I'm still running the factory battery charger, with 5 one year old group 27 wet cells.

No need to upgrade at this time, but when we hit 3-4 year mark, I'll yank the wet cells and upgrade to the Pro-Nautic 60 amp charger.

Good to know the genny battery is included in the shore power CONVERTER charging system and that the factory alternators will in fact not overcharge the new generation of batteries.

Did the CAT alternators fail on the charging side (armature/diodes/regulator) or due to bad bearings?

BEST !

RWS

 

[ttmott]

I would assume that you adjust the alternator output voltage once you have fully charged the batteries and this will give you the correct absorb voltage...probably something in the 14.2V- 14.4V range.

If adjusting under a heavy load, the voltage will be sagging down likely in the 13.8 (or lower possibly), and give a higher 9and possibly too high) voltage once the load subsides.

I don't think they are that sophisticated. Those internal regulators will vary current depending upon battery resistance; they don't have a step function like an external regulator would. I set mine up on the 400DA with the batteries about 50% DOD (which is 75% charged) and engines at 1000 RPM. This, I thought, would be a best case bulk charge scenario. 14.4V using a DVM on the alternator. Batteries were AGM. A couple of things that led me to this method -
First the conductor length between the alternator and battery and the variable voltage drop which is due to the current demand from the battery bank. Sea Ray boats typically run the alternator B+ through the engine starting motor then the battery switch and finally to the batteries; not a direct fused link to the batteries. I suppose that you could set up the alternator based upon the voltage at the battery ensuring the alternator was putting out near maximum current (the batteries were hungry).
Secondly, the other demands on the battery bank will taint an alternator output voltage if measured at the battery.
Just me and the way I think about it as a system.

 

[ranger58sb]

I had a Pronautic 60A convertor and we hanged all my batteriews to Red Top Optima AGM batteries in 1999 and never used another type of battery and she still has the last set of Optimas in her that I installed.

It occurs to me that if that was in 1999, the charger was more likely a ProTech, also by ProMariner but an earlier generation... with only two settings: FLA and Gel. The manual also said to use FLA for AGMs... but it wouldn't have been great for all AGMs.

No need to upgrade at this time, but when we hit 3-4 year mark, I'll yank the wet cells and upgrade to the Pro-Nautic 60 amp charger.

If you upgrade current (Amps) you'll want to be sure your wiring is sized to match, and some of that will depend on distance from charger to batteries... and back. Our previous boat started with a ProTech 1240 and when I wanted to upgrade to a ProNautic 1260... it would have been a major chore to change out the original wiring run. Turned out it was easier to ADD the 1260, installed much closer to the batteries and with new wiring... and we left the 1240 in place and operational too.

-Chris

 

[dtfeld]

Unfortunately if upgrading the charger, you have to look at both the AC wiring and DC wiring. When I replaced with the 1240 ProNautic a couple years ago, I concluded upsizing was too much work as well. I probably could have gotten away with a 1250, but the 1260 definitely would have required some new wiring.

 

[Strecker25]

another observation (question) -

I run the generator 100% of the time the mains are on and that means our 1240p is running as well. I would imagine if the charger is putting voltage into the main batteries and they're showing 14v+, the main engine alternators are not being asked to output anything?

 

[fwebster]

THANKS ALL !

….."Did the CAT alternators fail on the charging side (armature/diodes/regulator) or due to bad bearings?"


We are not sure but suspect diodes or regulators. Both dropped output to 7-9VDC . We didn't attempt to diagnose because the only 2 local rebuild shops only use Chinese parts and only offer a 30day waranty. That left me the option of Cat remanned alternators…….good, excellent warranty, but @ $935 ea from Cat was not reasonable when Leece-Neville OEM replacements were $260ea. The Leece-Neville (Prestolite) Replacements have been in the boat since 2016 and the boat still has the original non adjustable Convertor. As I recall, your 450 and mine are only few production #'s apart and have production dates only a few weeks apart.

Frank

 

[Magic]

Time to fire up this thread again with a few questions alternator type questions.

I have Redarc battery isolators that I noticed were alarming with the 2 red flashes indicating overcharging.
Because the batteries were fully charged and the engine was idling, I put a voltmeter on my Stbd Alternator and found it was outputting 13v and climbing (to well over 15v).

I disconnected the battery charge line at the battery and measure 30v output (no load) on the Stbd Alternator and 0v output (no load) on the Port Alternator.

Now I'm confused.
Are they both faulty?

Not sure whether they are the originals, but the Stbd one definitely looks like a Prestolite 8MR2070TA, although I forgot to check if it had a voltage adjustment screw in the regulator...will check next time I'm at the boat.