Batteries - Gel, AGM or Deep Cycle?
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Batteries - Gel, AGM or Deep Cycle?
We are looking at replacing all of the batteries aboard our boat. We would welcome some input from this board as to which way would be best to go. Gel, AGM or Wet Deep Cycle. Right now we can get a very good price on some German 8D Gel Batteries. What size and type of batteries do you use? What is the size of your bank? Thank you
Paul:
I read several article on this subject, including a battery review by Practical Sailor. The conclusion that I have drawn is that if you can afford them, AGM's are regarded as the best money can buy.
Others may have a different view, but that it what my research ha disclosed. I have AGMS in my boat and after two years of very heavy use, have had no issues whatsoever.
Regards,
Rob Schulte
I had to replace my Rolls batteries because I had not done proper equilizing charges on them and they sufidized. Filling with water was very difficult (I have a 38 MKII). I went with AGMs for these reasons and so far am very pleased. Ask me again in a few years - that wil be the real story.
I favor 6V deep cycle wet cells. They are less expensive per amp hour and easy to replace anywhere you travel. We have Trojan brand.
Mark
On First Light we have returned to AGMs. Started with Rolls which failed due to a faulty shore side 110 charger. The AGMs worked great until needing replacement in the Azores. They don't do AGMs in the Azores. The traditional wet 4D replacements were fine except for on our 33T, mounted under the 1/4 berth, I did not like the gassing that was inevitible with no convenient ventilation. We have returned to AGMs and I love them. Just be prepared for two things: when they fail, there will be no warning. They just stop working. Secondly, some cruising areas do not stock AGMs. Finally, that said, we would go with AGMs for the primary reason of gassing and location in our boat. Good luck on your choice.
Paul,
I use Trojan 6 volt wet cells, golf cart batteries, because they are very affordable here in Florida. As long as I keep up with the equalization and monitor the distilled water level, they will last a long time.
I had one occasion that my Heart Interface/Link 2000 monitor became locked into a high voltage-high current charge mode because of an electrical storm-induced power surge at my marina. My 6 Trojan 6volt batteries were overcharged all day until I got home from work and re-set the charger. I added distilled water and they came back to normal charge/discharge cycles. That was over a year ago.
If I could afford AGM batteries, I would replace my wet cells. But at less than $60 each, it is still my choice to use 6volt wet cells.
Art
1986 HC 43T
We have 6v AGM batteries on our HC33, and have been very pleased with them (they are now 1.5 years old and still performing great). The advantage of the AGM over the wet/flooded batteries are:
1. Sealed, so no water to check and fill
2. more discharge cycles than flooded batteries (in some cases twice as many cycles or more)
3. does not require venting (though it's still a good idea when possible)
4. can be mounted in virtually any position
5. no acid to spill if tipped or punctured
6. more amp hours (in some cases)
7. not sensitive to charge voltages like Gel batteries
Disadvantages
1. initial cost (though cost over life of battery may not be more than flooded)
2. heavier than wet
We went with the 6v batteries because it is easier to carry than one 4d or 8d battery. Two of these will typically have 220 amp hours. We went with the Lifeline brand.
When comparing AGM batteries, not all are made alike. Besure to compare discharge cycles (indicates designed life of the battery under ideal conditions), and amp hour capacity.
Gel batteries are very sensitive to charge voltages, and will not tolerate deep discharges or over charging very well. Wet batteries are available worldwide and can be found inexpensively, but again, be sure to compare the designed discharge cycles and amp hour capacity as not all are created equally.
We installed 6 6v batteries under the aft cabin berth for a house bank of about 660 amp hours, and have a group 31 in the lazarette for the engine start battery. All are AGM. You can see pics of our installation at http://www.bruadair.us/html/projects_and_upgrades.html.
Damon
s/v Bruadair
www.bruadair.us
I have four AGMs on Pegasus - three for the house, one for starting.
Sam
Damon, I really enjoyed the photos of your completed projects; thank you! Please let me know when you complete the autopilot installation. We have that effort ahead of us as the ancient but honorable autohelm has to be replaced. Secondly, your battery box is beautiful. Is there a positive lock down for the batteries, aka, to keep them in place in the event of a roll? Just curious how you worked this in. Thanks again, Chuck; First Light
Hi Chuck,
Thanks for the compliment. In regards to the battery bank, yes and no. Currently I have battery tie down straps in place to hold the batteries, however I am in the process of putting in a positive lock down system that would be more secure. I'll take pictures when it's done and add it to my site, it'll be a few weeks. The bulk of the autopilot is installed, only the hydraulic linear drive remains. I'm hoping to get it done by the end of June. On another note, David and I finished building and installing our new teak deck box, I'll be taking pictures this weekend and will post them here. It came out great!
Damon
s/v Bruadair
www.bruadair.us
Charles,
I'd love to hear some more details about the batteries on your 33. As you may know the standard batteries (at least on the late boats) are 2 Group 27s located just inside the lazerette. (We've added a dedicated start battery to these.)
It seems the only real place is under the quarter berth...
Art,
I had the same thing happen to my Heart EMS 1800 after a power failure with several quick "ups and downs". Only it never functioned again after that, would never come out of bulk charge. We nursed it along in "Low Charge" where it would float the batteries (we live aboard) until it even stopped passing AC through a couple weeks later.
This was all a few weeks ago and I replaced the unit with a PROsine 2.0 (true sinewave) charger/inverter which I am very pleased with. The only small disappointment is that it requires a cooling fan (which is driven by two temp. sensors). Still, it may last longer this way...
- Steve
Art and Steve,
That's interesting. I have a Freedom 20 controled by a Link 2000R. Haven't given lightning induced power surges any thought. I think I'll look into a surge protector to put in the shorepower line. By the way, just to add to the data base, I have 6 volt house batteries.
Ken
Damon,
I just spent some time perusing your site. Very nicely done! Thanks for documenting everything so well.
We are going to take some ideas from you such as your bimini (do you have any photos of the details we could use?).
Also, I find it interesting that some sealed batteries require equalization. Though I have to admit that when our Heat Interface went nuts and bulk charged our Gels for too long (I thought they were killed) they are now performing better. Yes, I know that Gels are voltage sensitive and that this is not proper handling... Fortunately we caught the condition before any gassing occured and I think it did them some good. These are West Marine Group 27 Gels made by Sonnenschein and they were fitted April of 1994!
In fact this is just the 4th set of batteries since 1986. The first two sets were wet cells that lived a short life due to the cheap ferro resonant charger that HC installed. In fact the third set (the first time we used gels) did not last that long either. We installed the 4th set (the second set of gels) when we replaced the original charger with the Heart interface. I believe that made all the difference in our long life with this set.
I had plenty of opportunity to test them during the 2 weeks between when the Heart stopped passing AC through and when the PROsine 2.0 got installed (which took 2-1/2 weekends). It was also a good test of the Balmar 100 amp alternator and the MaxCharge 3 stage regulator (of which I'm very satisfied with).
Art,
Photos not necessary as Damon's site provided enough detail for me to build a battery box under the berth. Though I wouldn't mind hearing some of your experience, where the box is (same as Damon's?) and what type, size and number of batteries you are using.
Thanks, Steve
Just another thought on our battery box under the quarter berth. We built the box to not only accomodate our six 6v agm batteries, but it is also sized to accomodate two 8D batteries. We did this to have some flexibility in the future, especially if 6v batteries could not be found during our cruise (if new batteries would be needed).
Steve,
I'm glad to hear your gel batteries have lasted so long. The gel batteries are good batteries as long as one properly watches the charge voltages. I agree with you that having changed the battery charger helped you to get a long life. One of the biggest mistakes I see is customers purchasing hundreds of dollars worth of batteries, but not ensuring their battery charger is suitable for them. I typically urge my customers to protect their battery investment with a new charger (if it's needed) to ensure their life isn't shortened by incorrect charge voltages. Though sealed batteries typically aren't supposed to be equalized, Lifeline Batteries reccomend it on their AGM batteries. It these batteries, it should be done at 15.5vdc for three hours, once or twice a year. I also usually recommend that anyone wanting to replace their batteries to go through an equalization process first. Many times the batteries will gain new life for a bit, and the customer doesn't have to go throught the time and expense to replace the batteries (yet, anyway).
I'll see if I can get some detailed photos of the bimini posted this weekend.
damon
Thanks for the feedback Damon,
Barb's been looking forward to a Bimini project but we haven't been able to conceptualize a design we're happy with. Your's seems ideal.
One of the faults of the Heart EMS 1800 is that you could not change the charging algorythm nor the low battery cutout voltage (inverteer operation). The cut out was 10.5, way too low for gels. Fortunately the voltages supplied by the Heart were (just) withing the Gel's tolerance level.
The PROsine has over 20 pre-programmed charging algorythms for different batteries and ability to define your own. And it's (slightly) less complicated to do so than to set up a VCR.
I've measured my HC built battery boxes and I think they will accomodate Group 31 (they have 27s in there now). If I stayed with the WMP Gel that would take me from 86 to 97 AH. it looks like the Group 31 AGMs give me 105 AH. However I'm disappointed in the "300 cycles" rating (The SeaGells are at least 500 cycle rated.)
I have two questions... What's the difference between the SeaVolt AGMs and the SeaHawk AGMs? Same price, same description.
Also what's the difference between the SKU 327025 SeaGell and the SKU 5320494 SeaGell?
Sorry for all the questions, but I cannot find answers to these...
Thanks, Steve
Steve,
Also what's the difference between the SKU 327025 SeaGell and the SKU 5320494 SeaGell?
The SeaGel is produced bya company called East Penn Manufacturing. The difference between the two SKUs is that SKU 327025 carries the SeaGel label with 'West Marine' printed on it, where as SKU 5320494 did not have West Marine on the label. The first SKU is basically a private label SKU, the second SKU (as I understand it) is being phase out of WM's inventory.
I have two questions... What's the difference between the SeaVolt AGMs and the SeaHawk AGMs? Same price, same description.
Actually, these are identical batteries except for the label. These batteries are also produced by East Penn. The SeaHawk label is not exclusive to West Marine, whereas the SeaVolt label is exclusive only to West Marine (It too has WM on the label). Just a private label issue again.
The battery box in the lazarette will hold the Group 31 battery, provided all our battery boxes were built the same size. This is where we keep our Lifeline AGM group 31 battery for the engine.
it looks like the Group 31 AGMs give me 105 AH. However I'm disappointed in the "300 cycles" rating (The SeaGells are at least 500 cycle rated.
Well, here is another one of those product deceptions. Though the SeaGells are rated at 500 discharge cycles and it appears more than the AGM's 300 cycles, the SeaGells actually have less cycles. The reason being is that the AGM is rated at 100% discharge and the Gell is rated at 50% discharge. When the AGM is rated at 50% (same as the Gell), it's discharge cycles are actually 600 cycles, more than the Gells 500. Battery manufacurer's will either rate their products at 50% or 100% discharge, and though this information is not on the label, a good consumer needs to know this to accurately compare batteries.
Keep in mind that not all AGM batteries are built alike. We chose the Lifelines due to their 1000 discharge cycles (rated at 50% discharge). A bit more expensive, but a longer life overall. I am a bit biased though, as I sometimes don't trust private label products to have the same quality. Something I would consider if you are planning on increasing your battery bank (under the quarterberth) is to use the better quality Lifeline for your house bank as it will be the 'working bank', and maybe use the WM brand AGM for the start, as it will not be worked as hard. If you are just planning on replacing the two group 27s with 31s, I would go with the Lifeline batteries. You should be able to find a distributer of Lifeline close to you, or you could check on line. I know that Bill at Everfair (makes of the Fourwinds wind generator www.fourwinds-ii.com) sells them. I'm not sure how their pricing is, but shipping may be less than what you would have to pay for sales tax. (tell bill hi for me if you call him).
If you find Concorde AGM batteries, they are the same as Lifelines (same company). Also, Lifeline has a good couple of graphs showing their discharge cycles, one compared to gel batteries. The links to the two graphs are at at http://www.lifelinebatteries.com/graphs.asp.
Your correct, the Freedom does have it's limitations, but it appears to be working just fine for you. I really like the prosine units, have installed quite a few and haven't had anyone complain about them yet. We have been contemplating putting one of their inverters on our boat, but so far the 500w meets all of our ac needs. Maybe when it dies we'll get the Prosine.
Didn't have time to take pictures of the bimini today (had a chartplotter to install). I'll try tomorrow.
Hope this helps some. Let me know if you have any more questions/comments.
Damon
s/v Bruadair
www.bruadair.us
Damon,
Thanks so much for taking the time to produce a timely and well though out response, it helps greatly.
The PROsine 2.0 has been installed for a week and I have spent much time learning the configuration options and how to interpretthe diagnostic information. Pretty cool, all-in-all.
I was beginning to wonder about those "cycle" ratings, thanks for the clarification.
I took a look at the Lifeline site and see by their data that AGM batteries are not simply a commodity - not at all the same from maker to maker. Out WMP Gels are so old as to be still made be Sonnenschein. I wonder how the quality comparison is...
The prices I saw on the web for Group 31 Lifelines were about $250-$260. That, compared to the $190 for the WMP version... Even though I have a Port Supply account I'm going to go with the best product.
BTW, I replaced the liquid electrolyte battery in my airplane (battery acid has no business in an aluminum aircraft!) with a Concord AGM 3 years ago and I have been exceptionally pleased. The biggest noticable differences are lower self discharge and better ability to deliver starting power. (Months of sitting in the winter and I can still start - and - the high torque, voltage sensitive starter spins faster.)
I'm hoping to get two Group 31s in the battery box that now holds 2 27s (I've added a box just aft of the original (on the remaining shelf) to carry the start battery (also a Group 27).
Thanks again Damon,
Steve
Steve, sorry to be late in getting back to you on the question about batteries on our 1984 33T (Yanmar 3QM and Westerbeke 5BCD generator). We have two 4Ds for the house located in a battery box under the quarter berth aft of our Grunert refrig compresser and forward of the water heater. We also have dedicated group 24s, one each for the generator and the Yanmar located in the lazarette against the bulkhead (I think where most 33s have their batteries located). Separate battery switches allow us to use one, two or three batteries, the 4Ds acting as the house bank. A Newmar 110 battery charger, an Aerogen 6 wind generator and a 90 series Balmar alternator do the charging for us. Hope this responds to your question about the batteries. Chuck.
Thanks Chuck,
That helps me get an idea of what's possible. I agree with the philosophy of a dedicated start battery. And with the ability to be able to backup the start battery. On Warmrain we have a switch that allows us to start off the house batteries - or even run an emergency draw (e.g. radio) off the start battery.
Yes, I think the standard place for the 2 group 27s that HC delivered their 33s with are just inside the lazarette hatch just aft of the forward most bulkhead. That's how Warmrain came from the yard.
This is the smallest useful resolution, showing Warmrain's DC system.
I built a battery box for the dedicated start battery next to the original equipment boxes.
All batteries are group 27s. As you might suspect, the original boxes look like they (and measure like they) will hold Group 31 AGMs. That is the difference between 86 and 105 AH each battery.
The additional start battery box is designed for a group 27, you can see how much smaller it is than the original.
- Steve
Chuck,
I finally finished the 'positive lock down' on our batteries today, so here are a couple of pictures. Basically I used parts that I already had on hand, and the two scrap pieces of s.s. tubing I had were the perfect length. The parts you see in the pictures are bimini fittings. To remove requires removing a couple of screws, but I wouldn't think it would have to be done except to remove the batteries. There are 1"x1" teak strips at the base to keep the batteries separated and prevent shifting, and I left in place the battery tie down straps. The ss tubing is about an 1/8" or so above the batteries. Let me know if you have any questions,
Damon
s/v Bruadair
Beautifully done, Damon! Aren't you pleased when your vessel is greatly improved over how she was before your efforts? A class act. Thanks for sharing. By the way, are the two Racor filters for the propulsion engine or do you also have a generator? Chuck
Can someone share a quick lesson in battery sizing . . . I understand that a battery has an amp-hour rating and a rating for the number of times that it can be cycled . . . however, I've always wondered what the "Group" designaton refers to as in "Group 27" ??
Regards, John Robinson, s/v Crossings
John,
AFAIK just an industry standard for the case size (e.g. like 4D and 8D). The amp./hr. rating will be a little different depending on the battery design (e.g. AGM, GEL, liquid electrolite).
Discharging past 50% descreasing rapidly the number of cycles the battery will last. Though Sonneshein (sp?) says you can take their GELS to 40%...
- Steve
By Paul Guenette on Wednesday, May 26, 2004 - 08:10 am: Edit
