Battery selection and comparison by PS

[Don S/V ILLusion]

There has been much discussion recently regarding battery comparisons and thought some might find the attached PS article of interest


http://www.llelectronics.com/docs/aw...eBatteries.pdf

 

[Ed Schenck]

Really appreciate that Don. Gives some credence to my choice of four house AGMs and a 900CCA AGM for starter. I use an 80 amp Balmar and 3-stage regulator with a Link 2000 on a Heart i2000 inverter/charger to keep them charged. If they last as long as my previous gels(8 years) I will be a happy sailor.

 

[Roger Long]

I'm surprised to see in that article the reference to AGM's needing "precise charging profiles". Everything that I've read previously and been told by several professionals is that they are perfectly happy with the same chargers and alternators as wet cells and that it is gel cells that need special care and feeding. My AGM's have been running happily on my plain vanilla alternator since 2005.

 

[Maine Sail]

Good post..

I'd read that a while ago when it came out and wrote to PS asking for a controlled comparison of life cycle (how many times can the batteries be discharged to 50% before failure) and they responded that is was something they want to do.

I also asked for a 6V lead acid battery test of varying brands and they responded that it too was something they wanted to do. Of course this was 2006 and they still have not done either??

Capacity measurements are a good test but life cycle/longevity is one I'd really like to see..

 

[Maine Sail]

Good post..

Don,

I'd read that a while ago when it came out and wrote to PS asking for a controlled comparison of life cycle (how many times can the batteries be discharged to 50% before failure) and they responded that is was something they want to do.

I also asked for a 6V lead acid battery test of varying brands and they responded that it too was something they wanted to do. Of course this was 2006 and they still have not done either??

Capacity measurements are a good test but life cycle/longevity is one I'd really like to see..


Roger,

That article was from 2006 and back then I remember some AGM manufacturers suggesting specific charge profiles as well as folks like Balmar & Ample recommending the same.

I think certain AGM companies have re-addressed these charge guidelines in order to move more units as it's easier to sell a battery to a guy with a "dumb" regulator if they don't also have to spend 1k on a new alternator & regulator system. More volume for the AGM makers means lower prices for you and I..

It benefits the manufacturer to say they will charge on the same profile as a lead acid because many boaters still do not have "smart" alternator regulators.

Trojan is one maker who still recommends a different profile for the optimum results.

Trojan Lead Acid Suggested Charging 12V
Daily Charge 14.8V Float 13.2V Equalize 15.5V

Trojan VRLA Suggested Charging 12V
Daily Charge 13.8-14.1 Float 13.5

Trojan Specifics for VRLA Batts

Additional VRLA Charging Instructions:

1. Become familiar with and follow the instructions issued by the charger manufacturer.

2. Verify charger has necessary VRLA setting.

3. Set charger to VRLA voltage settings (Table 3).

4. Do not overcharge VRLA batteries. Overcharging will dry out the electrolyte and damage battery.




Lifeline AGM's can be charged with dumb regulation at standard lead acid voltages. This comes straight from Lifeline's tech support five minutes ago. While they do say that optimum life is achieved through a smart charger they also say it's no problem to charge them on a wet cell charge profile?

For those with a "dumb" regulated alternator this makes Lifeline a more attractive AGM battery than a Trojan AGM because there is no alternator upgrade necessary or additional expense necesary.

Honestly I am at a loss as to why one maker has fairly stringent guidelines on charge parameters and another does not..? I think buying AGM's requires a little more research to match your vessels charging capabilities than does buying lead acid batteries.

 

[Roger Long]

It benefits the manufacturer to say they will charge on the same profile as a lead acid because many boaters still do not have "smart" alternator regulators.

Well, that is certainly something I can believe. When my obsession was aircraft, I learned that the engine manufaturers were recommending that fuel mixture (which the pilot has to adjust constantly with altitude) be adjusted to the setting that put the most stress on the engines, fouls the plugs fastest, and leads to shortest time between overhauls. It was based on just the same kind of reasoning but you can't simply go out and buy a new airplane engine the way you do a new battery.

Trojan is one maker who still recommends a different profile for the optimum results.

"Optimum" is a slippery word in this kind of discussion. Often, in things like this, it means just a few percent more, differences that may not be detectable without carefully controlled comparisons. It also could be (which I highly suspect) that special charging isn't needed for normal service but becomes important if you are routinely squeezing every last amp out of your batteries and then trying to get them recharged in a short time period. The guy on a boat with AC and a 3 case beer cooler who has to go through the whole cycle on a Sunday afternoon because he's sailing from a mooring for example.

I looked at having the onboard regulator on my alternator disabled and adding a 3 stage separate regulator but I could simple buy two more AGM's for the same price. They seem to last long enough that there has to be some significant life extension for it to be worthwhile.

 

[Maine Sail]

Optimum was not Trojan's word..

"Optimum" is a slippery word in this kind of discussion.

Sorry for that, "optimum" was my word NOT Trojan's. They are pretty clear on how they want it charged.

I still don't get why Lifeline's can charge at lead acid rates and Trojan's does not recommend this..

 

[Stu Jackson]

I think certain AGM companies have re-addressed these charge guidelines in order to move more units as it's easier to sell a battery to a guy with a "dumb" regulator if they don't also have to spend 1k on a new alternator & regulator system. More volume for the AGM makers means lower prices for you and I..

It benefits the manufacturer to say they will charge on the same profile as a lead acid because many boaters still do not have "smart" alternator regulators.

Trojan is one maker who still recommends a different profile for the optimum results.

Could it be that they recognize that an unregulated tapering charge from an internally regulated alternator with standard output of 13.4 to 13.8 V wouldn't damage a battery by overcharging, although it would be chronically undercharged but little noticed by "Average Boater Joe?"

 

[Maine Sail]

Just wondering

Could it be that they recognize that an unregulated tapering charge from an internally regulated alternator with standard output of 13.4 to 13.8 V wouldn't damage a battery by overcharging, although it would be chronically undercharged but little noticed by "Average Boater Joe?"

Stu,

I've seen you reference 13.4 to 13.8 before as the output voltage for stock regulators and am wondering where you got that from?

Prestolite / Leece-Neville the makers of the stock alternators on Universal engines specs 13.8 as the bare minimum output and a range of 13.8 to 14.2 as normal.

On the after market Leece-Neville alts the voltage regulator is adjustable but on the fixed voltage regulators the range is 13.8 to 14.2 as normal..

 

[Roger Long]

I still don't get why Lifeline's can charge at lead acid rates and Trojan's does not recommend this..

This is a pretty basic technology so it's unlikely that there is a significant physical difference between the batteries. If there were a big physical difference, you can be sure Lifeline would have an advertising campaign about it. If it wasn't protected by patent, Trojan would probably be using it. That would mean that the difference has more to do with secondary issues such as marketing, number of guarantee claims considered acceptable, etc. That is a strong indication that the differences between the results of charging rates, while finite and measurable under controlled conditions, is one of those "signal lost in the noise" kind of things.

A fancy external regulator has a great "cool" factor and I wish I had one. I don't see much evidence that it would extend the life of my batteries more than maybe a month or two so I think that money would be better spent.

 

[Don S/V ILLusion]

Roger
The difference in charging scheme might relate to the construction of the gel or fiberglass-mat (AGM technology), not all of which are spun technology plates vs. the more traditional variety. I can think of no other substantive reason for the caution regarding charge voltage.

 

[Stu Jackson]

Internal Automotive Regulators & Charging Source

Stu,

I've seen you reference 13.4 to 13.8 before as the output voltage for stock regulators and am wondering where you got that from?

Prestolite / Leece-Neville the makers of the stock alternators on Universal engines specs 13.8 as the bare minimum output and a range of 13.8 to 14.2 as normal.

On the after market Leece-Neville alts the voltage regulator is adjustable but on the fixed voltage regulators the range is 13.8 to 14.2 as normal..

Maine Sail

Internal Regulators

Only reason is that the standard internal regulators on most OEM Motorolas in the older boats were not as nicely configured as your examples, and were "automotive" (like, in "cars"). Just enough to juice 'em, but not enough to boil 'em over by ever overcharging.

Charging Regimen Source

A good reference for charging for different batteries is on the Balmar website, in the manual for the MC-612 regulator. See page 9 of 17 on the PDF file here, scroll to the bottom of the page: http://www.balmar.net/PDF/2005-mc-612-manual.pdf

Also see Reply #24, here: http://c34.org/bbs/index.php/topic,4766.msg28646.html#msg28646

Stu

 

[Maine Sail]

I just measured

Maine Sail

Internal Regulators

Only reason is that the standard internal regulators on most OEM Motorolas in the older boats were not as nicely configured as your examples, and were "automotive" (like, in "cars"). Just enough to juice 'em, but not enough to boil 'em over by ever overcharging.

Charging Regimen Source

A good reference for charging for different batteries is on the Balmar website, in the manual for the MC-612 regulator. See page 9 of 17 on the PDF file here, scroll to the bottom of the page: http://www.balmar.net/PDF/2005-mc-612-manual.pdf

Also see Reply #24, here: http://c34.org/bbs/index.php/topic,4766.msg28646.html#msg28646

Stu

I just measured both my wife's Honda, and my Ford, for grins.

Honda 14.42 volts OE battery 6 years old 130k miles.

This Honda battery was, once again, killed totally flat on Monday and I got the call from my wife for a jump. This is now about the tenth or eleventh time this has happened because of the position of the dome light switch that gets hit. Battery is still going strong even with "boil out" voltages, many miles and much abuse.

Ford 14.56 volts 1 year old OE battery 59k miles (yes I drive a lot)

 

[Stu Jackson]

I don't doubt it

so when my leg gets better I'll go measure my two cars.

My experience with my old OEM Motorola alternator with my Auto Mac and both voltage and amperage analog meters was no higher than 13.8 V from the stock internal regulator at cruising RPMs unless I employed the Auto Mac, which raised the voltage and the amperage. For those not familiar with the Auto Mac, it was old school external regulation technology that really regulated both the voltage and the amperage as was covered in detail in Calder's Boatowner's Manual, 2nd Edition.

Thanks, Maine Sail.

Stu