AGM Batteries

[mike]

We have 110 alternator with a Sterling charge unit giving 4 stage charging we rely on + the wind genny in summer - solar panels are a mixed bag as we aqre so far north.
In winter on the marina its rare for us to have low batteries because of the wind genny although when on board we automatically have our 4 stage shore power charger on but this appears only to give the last long low amp cycle of the 4 stage charge.

mike

[steven_cleary]

Hello,

I've continued to research the battery topic and have some additional info that may be of interest to others on this thread.

1. If possible, it's best to have a higher amp hour single house bank, rather than multiple parallel banks. I'm considering going with 2V cells for my redo. Lifeline is due to release a 900 amp hour 2V cell in a 10.25(L)x7.25(W)x12.65 (H) configuration. Using the 2V option, they will fit in my existing 8D battery boxes. Due to differences in impedance, it is less desirable to charge parallel banks...this accounts for premature failure because some batteries get undercharged consitently, sulfate and lose their capacity.

2. Acceptance rates for charging directly affect how long you'll need to run your engine/charging system. The rates are expressed as a percentage of the total amp hour rating of the bank(s). At a 50% DoD (depth of discharge) acceptance rates are typically 25% for wet cells, 40% for GELS, and 100% for AGM. The important point here is that you can recharge an AGM at least 4x quicker than a wet cell bank and at least double that of gells. For a cruising sailor this should be of paramount importance. Keep in mind that the rate of acceptance declines as the battery charges, it is not linear and by 80% charge wet cells are accepting roughly 3% of their rated capacity. I was unable to find detailed information on AGM/Gell as they approach full charge, but I would suspect they track similar to wet cells.

3. Keep the acceptance rate in mind when sizing your alternator and battery charger. Relative to the battery charing function of the alternator/charger....if you have wet cells, there is no point to having an alternator/charger that is rated at greater than 25% of your bank capacity as the batteries will not accept more than that rate of charge. On the other hand, if you have Gells, your alternator/charger should be rated for 40% of the capacity of the bank(s) for most efficient charging. With AGM, get the biggest alternator/alternator you can afford/fit into the space you have for fastest charging.

3. There seems to be some evidence that using a pulse device like the nano pulser or similar will dramatically extend the life of batteries that are cycled the way a cruiser would cycle them. The theory is that the pulses break up the sulfation on the plates. These devices are often credited with restoring batteries that are otherwise unusable.

For the gear heads in the group, I found the site below with some great info. This person put some serious time into a comparison. There are software models you can download for doing your own calculations:

http://www.vonwentzel.net/Battery/index.html

[sv_bruadair]

Well, nothing seems to be easy here in Roatan, Honduras. Before flying back to California I had ordered my 6 Trojan T-105s, Sonny from Valentina had ordered the same. We had placed our order on December 22nd and were assured they would be ready to pick up by the time I returned from California. So on January 15th Sonny and I made our way to the store only to find out there were no batteries. For one reason or another the order fell through and despite having phone numbers and email addresses no one had contacted us.

But luck was on our side. I put out a request on the NW Caribbean Net for information needed on 6v batteries, Greg on Lone Star Love was in La Ceiba and told us that Lagoon Marina had some. So Sonny and I placed our order and two days later we had 12 Trojan batteries. Yeah!!!!!!!

They’ve been in the boat now for a week and what a huge difference in performance. Just hope it stays that way for years to come. Prior to taking out the Lifeline AGMs we could only squeeze out about 80 amp hours before the batteries were reading 12.15vdc, so far we have been able to get 225 amp hour out of our 660ah bank and still maintain 12.35 vdc. Not bad. By the way, Sonny had Lifeline AGM batteries (4 8Ds) that were only three years old and was having the same capacity problems. Two other boats here that have AGMs have placed their orders for Tojans as well.

A week isn’t really enough time to evaluate the Trojan batteries but based on their reputation, what other cruisers have experienced and what we’re seeing so far we’re satisfied with our decision to purchase them.

Our electrical system on the boat now consists of :

6 Trojan T-105 batteries (675 amp hours)
Water Miser battery caps for the above
Freedom 1500w inverter/ 75 amp charger
Honda EU2000i 2kw Generator to run the above at anchor
Balmar 100 amp alternator with smart regulator
Fourwinds II wind generator
2 Kyrocera 120 watt solar panels
Link 2000 battery monitor

We’ve just pulled out of Sandy’s marina in Oakridge and are at anchor in Port Royal. I’m excited to see how long we can go at anchor before having to run the battery charger or engine to charge the batteries.

[warmrain]

Damon and David,

What are you using for an anchor light?

[sv_bruadair]

We're using a combination tricolor/anchor light, it's an LED light made by Orca Green (www.orcagreen.com). Love it. USCG approved. One of the reasons we chose this light was the ease of wiring. There were two wires going to the original anchor light. This light from Orca Green only requires two wires with a three way switch. With the switch in one position, positive is on one wire and ground is on the other lighting the anchor light. With the switch in the second position the polarity is reversed, lighting the tricolor light. The third position turns off the light. Wonderful service, wonderful light. burns about half an amp and very bright. Best of all it was easy to install. We could use the previously installed wiring. Other lights would have required we drop the mast and run a third wire for the tricolor. That wasn't an option for us. There was enough wire at the top of the mast on the old anchor light to be able to cut and splice in the new light. Kind of expensive (what isn't), but well worth it.

Damon

[warmrain]

Great! And for others that are lurking there are now LED replacement bulbs for bayonnet type anchor lights that area direct replacement. We are using one in our AquaSignal tricolor.

[sv_bruadair]

The running lights at deck level on Bruadair are Aquasignal Series 20 lights. We replaced all the bulbs three years ago with LED inserts (direct replacements) from Orca Green, still doing great. Previous draw was 3.8 amps, current draw is .6 amps. My understanding is that Orca Green is no longer making these inserts. Wonder why.

[warmrain]

We left the deck level lights as 20 years ago they were changed from the shoddy originals to bronze lights from Italy. THe tricolor is what we use when sailing... so the LEDs are there...

Dr. LED seems to have all the lights to fit Aqua Signal.
http://www.doctorled.com/

It seems Orca Green LEDs are back.
http://www.orcagreen.com/

[sv_bruadair]

Have heard great things about doctorled.com too.
I think it's great that some sailors are looking at more amp efficient anchor lights, maybe that will mean that more and more boats will actually end up using their anchor lights at night. It continues to be frustrating at times, for example here in Port Royal right now. There are 12 boats anchored here but we are the only one that turns on an anchor light. Throughout the entire night there are small boats buzzing around and it's hard to see any of the sailboats when there are no stars or the moon to provide some light. We once left a crowded anchorage where 9 out of 10 boats weren't lit up, we needed to leave before sunrise to make our destination before sunset and had a hard time avoiding boats as we just couldn't see them until we were too close to them. And during squalls it's impossible, without a light on, to see boats dragging around or on top of you.

While 'designated' anchorages don't require an anchor light it's nice to see them on. Having an LED anchor light means we don't need to worry about the 6 amps it uses every night. Maybe more and more boats will use them if the prices continue to drop.

Just my thought,

Damon

[warmrain]

Agreed 100%. We entered a crowded anchorage at night in a squall and no one was lit. It was after mid-night and I paid them back with the fog horn blaring as I came in. They were easier to see with the cabin lights on...

[sv_bruadair]

Excellent idea, might try that the next time.

[remetau]

[mike]

[warmrain]

We've been getting 10-12 years from Gel cells which I beleive are better for our needs than AGM (the latter we use in the plane). I think that long life is due to the fact they are charged properly and kept charged by a 3 step shore charger and a 3 step alternator regulator - as well as solar topping up.

I think that very high quality liquid electrolite batteries could last as long if impecably maintained. For me the Gels and AGMs in the boat and plane last longer because I don't get around to regular mainenance... and, the spill factor is a mess in the boat and a potential disaster in the plane (considering the boat is plastic and the plane aluminum).

Best, Cars

[sv_bruadair]

Hi Don and Diana,

Sorry to get back to you so long after your posting but we've been cruising in the San Blas Islands and there is no internet access available there. Today I flew to Panama City for a few days and today's my first day online since early January.

The Trojans are 3 years old and are still as good as new, if not better. We check the water level the first of every month and top off when necessary. Trojan has excellent tips and videos on their web site about battery maintenance so you might want to download them and save it on your computer for referencing later down the road.

The other thing we do on a regular basis is equalize. Trojan recommends once a month but we find every six weeks works well for us. You need a battery charger that is capable of equalizing, our set up is a Freedom 1500 with a 70 amp charger which we run off the Honda 2kw generator. I should say that's the way we used to do it. We added two more solar panels in December for a total of 500 watts so we've only had a need to run our Honda once since then. We're running computers, water maker, lots of stuff and have too much electricity (I know, it's a shame!). With our four solar panels and one wind generator we generator about 200 amps a day (145 amps solar, the rest wind). We only use about 120 amps so we turn off the wind generator once in a while. But with this extra amps our solar regulator will allow us to equalize from the solar panels which has been working quite well.

The key to a long healthy battery life is maintaining the water, never going below 50% discharge and equalizing on a regular basis. We see so many cruisers buying new batteries every couple years because they won't equalize or they're to scared to do so.

Lifeline has posted on their web site that they do not recommend AGM batteries for cruising boat as it's impossible to charge them to 100% everytime a charge is applied. They also recommend equalizing their AGm batteries when performance drops (it's on their web site).

We like the Trojans. Currently in Colombia the T-105s run about $200 each and in Panama $185. Batteries are pricey down here so we're taking pretty good care of ours.