AGM Batteries vs Wet Cell

[Maren]

Originally Posted by GordMay

Professional BoatBuilder magazine (Issue 111 - February/March 2008) has an interesting article by Nigel Calder about new battery technologies, entitled: “BREAKTHROUGH” (begins page 104)

Goto: Professional BoatBuilder - February/March 2008

That was the exact topic I was researching today. Thanks so much for that and your other (always pertinent) links.

[speedoo]

Originally Posted by Hope Light

I plan to add solar and wind generation as well. In this day and age it seems stupid not to.
Thanks.

Have you given any thought to adding a Honda gas-powered generator? They are very quiet and could be run occasionally instead of your engine when necessary.

[Hope Light]

Speedoo,
Thanks for the suggestion. A small, quiet generator will definitely be part of my plan to generate electricity when needed. I have an old Honda now that will be replaced before I head out again. As you point out they are just getting quieter and more fuel efficient. When all else fails, its a great backup.

[speedoo]

HL, you probably saw the recent thread on the Honda generators, but here's a link in case you did not.

http://www.cruisersforum.com/forums/...ger-16312.html

[Strygaldwir]

Rick;

[Strygaldwir]

Rick;

It has been an additional year since your review of the full river AGM batteries. Does your opinion still hold? Is the AGM still viable? I appreciate the update.

Thanks.

Keith

[Beausoleil]

Originally Posted by Strygaldwir

Rick;

It has been an additional year since your review of the full river AGM batteries. Does your opinion still hold? Is the AGM still viable? I appreciate the update.

Thanks.

Keith

Keith,

I don't know if Rick has a detailed update, but I can give you our experience so far with the 800Ah Fullriver AGM 12V house bank we installed in June 2008. We moved aboard in July, with Beausoleil in a slip on shorepower. We set out in mid-September to begin our cruise. In that time,we spent about 3 weeks on shorepower in Annapolis, 2 weeks in Charleston, and a week in St. Augustine. Other than that, we've been on the hook with wind power and our genset.

We typically recharge when the bank hits a SOC (according to our Magnum battery monitor) of ~70-75%. We run the genset to bring it up to 90-92%, and about once a month let it go all the way to 98-100%. I also try to load up the genset as much as possible then by also vacuuming, using power tools, running the electric hot water heater, etc. We haven't done any equalization charging yet, but probably will sometime in the near future. As I posted in other related posts in the past, we typically use the Magnum Energy MS2812 inverter charger (125A) and an Iota Engineering DLS-75/IQ4 simultaneously for 200A total. Typically during initial bulk charging stage, the bank will accept ~185A. I turn one off when the current level in the absorption stage reaches 75A.

I've seen little degradation in the ability to hold a charge. FWIW

[hellosailor]

Jon, when you mention plans to do an equalization charge, does Fullriver say that will benefit their batteries? Most AGM makers (AFAIK all of them except Lifeline) say not to equalize, you'll damage the battery. AFAIK.

[Strygaldwir]

Jon;

Thanks much for the update. It is very much appreciated. It is apparent from all the articles I have read the the AGM type batteries have many advantages over the flooded cell. The question in my mind has been longevity. It seems many folks have had questionable life spans of their AGM. As Rick pointed out, it may be a result of undercharging. He stated a while back that he had a Fullriver AGM battery going for something like 5 years. I wanted to know if it made it to 6? Especially since I am about to buy a set of 4 of them.

[Rick]

Strygaldwir,
Let's see now, I have to check but I think I started testing those batteries 7 years ago. They still work well and exhibit low internal cell resistance and high charge acceptance.

The only time that I have used a true equalization cycle (requires a constant-current source) was to bring back from the dead undercharged AGM and gel-cell batteries which would not charge accept any normal acceptance voltage.

I have seen in the lab and on board that you will never need to equalize the AGM or gel-cell battery if you attempt to follow an Amp-hour law charge regimen that imparts voltages well above 14.4V @ 20 deg C. This will work well with flooded-cell batteries as well yet they still might require equalization yet less often than they would normally, if at all.

[Strygaldwir]

Rick;

Thanks for the update! I'll be ordering now. Thanks for getting me off my fixation with Rolls! Saved me some weight!

Keith

[Beausoleil]

Originally Posted by hellosailor

Jon, when you mention plans to do an equalization charge, does Fullriver say that will benefit their batteries? Most AGM makers (AFAIK all of them except Lifeline) say not to equalize, you'll damage the battery. AFAIK.

I should have issued that with a caveat: I'll do a detailed check the battery state before I do an equalization charge. From Fullriver's AGM Charging Instructions (PDF here):

Conditioning Charge: (Equalization)
This is the most misunderstood area in battery maintenance. Equalization of Fullriver AGM Batteries is not required on a routine basis. You should equalize only when the batteries need this process. Under certain conditions after prolonged periods (ie; cruising vacation) in which incorrect recharging procedures have routinely been used you may notice a reduction in overall capacity. Many times simply cycling the battery and fully recharging will equalize the cells. If de-equalization has caused a reduction in capacity, then sulphation may have taken place.

Fullriver battery construction techniques and material selections significantly reduce the possibility of battery capacity loss due to sulphation (buildup of hard deposits on the plates). However, like all lead acid batteries, sulfating can occur. Additionally, normal battery cycling tends to develop each individual cell slightly differently. To correct both minor sulfating and irregular cell development we recommend bringing the battery slightly past it’s gassing voltage for a short time period. This involves charging the battery at 15.0 - 15.5 volts for 12 volt batteries at approximately 6 amps for 3 to 12 hours.

[hellosailor]

Thanks, Jon, that makes two manufacturers who recommend equalizing. One routinely, the other in response to problems. That's still a minority opinion, seems to be?

I wonder if anyone who has the Fullriver batteries has used that procedure, and if so, if they've noticed the battery blowing off gas, as opposed to holding the pressure?

I still mistrust pretty much everything shipped from China. Being based in Miami, no doubt you've heard about the "Chinese Drywall" problem now, apparently they've shipped drywall boards with enough sulfur in them to destroy wiring and plumbing and household silverware as well.

"We are not amused." [Her Imperial Brittanic Majesty, Victoria]

[camaraderie]

HS...I agree with the Full River EQ statement. I also think most AGM battery mfrs. tell you NOT to do it due to their LEGAL departments and the danger involved and the ability to permanently damage the battery causing warranty claims. Obiously, there can also be some individual brand construction issues that would preclude an EQ cycle but I think most of it is legal beagles.
I further think that monitoring the battery temp to keep it below 160 degrees during EQ is the way to go rather than somewhat arbitrary range of numbers and amps. So...my advice would be:
If your battery needs EQ and you are going to do it regardless of mfr. cautions....
1. Don't make it a standard routine. Do it only when loss of capcity is evident.
2. Monitor the temperature and do not let it get over 160 degrees.
3. Check by hand for hot spots that are significantly hotter than the rest of the case or a bulging case as these could indicate shorted connections/bad cells. Terminate the EQ if this is found.

[Rick]

The electrochemistry literature recommends cessation of any charging for any lead-acid battery when the temperature reaches 120 deg F.

Do not confuse all Chinese products with poor quality. The Chineese did not successfully design, launch and place in orbit communication satellites they also have some very high quality manufacturing facilities pushing state of the art. Fullriver is one of these high quality sources. The purity of their lead plates is quite high else the self-discharge would not be as superior as it is.

Their recommendations, you may notice, are different from other AGM manufacturers and, in my opinion, much more realistic. Their approach to "revealing" higher limits for charging, etc. is probably because they do not have the "California-lawyer fear" of litigation.

The only time that I had to equalize a Fullriver battery was one that had been left standing without a charge for almost 6 years. I was careful to listen for gassing and adjusted the constant current source to keep gassing within the capability of the battery to recombine the chemistry without venting. The battery did not get hot merely warm, below 80 deg F.