Which AGM Battery ?

A

anniebray

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AGM Batteries appear to have many attractions for marine use but the cost can appear prohibitive. But then I looked up prices at Barden Batteries:
Lifeline GPL-31/ 105AH/ £220 +vat
Energy AGM100/100AH/ £115+vat
Energy AGM110/ 110AH/ £133 + vat
I might be convinced that Lifeline is the best but on price Energy appear the better buy. Would be interested to see what opinions others have on this. Does anyone have experience of using Energy batteries or even other manufactures of AGM types ?
 
You've already convinced yourself that Lifeline are the best - so whats a hundred extra quid to get the better product. Your profile doesn't show what boat or lifestyle you have, so if money really is the most important criteria then you could go for cheap car batterries! We could do with a dedicated forum on here JUST for this kind of question!!!!!!

I got fed up with being on other peoples boats who were always having battery problems so I went for Lifelines. You can mount them any way up, they can accept high current and faster recharge, etc, etc.. They were originally developed in 1985 for the aircraft industry - why not ask Barden what the real differences are?

I would also suggest go for the largest bank you can fit - we went for 5x 210 Ah with a 2.5KVA inverter - so we have AC anytime we want it. We can even run our 12,000 BTU Heating/Air Con from the batteries. If you're living aboard why not have all the home comforts you were used to?
 
Suggest you try Merlin 01202 697979 who list the Lifeline at £178 + vat. You may also be able to get a discount, particularly if you order at a Boat Show. No connection other than a satisfied customer - When one of my Lifelines failed after 3 years we came to a satisfactory compromise on the cost of the replacement.
 
We live aboard our boat and bought 3X 200amp Energy batteries in early 2006. So far they have been excellent. We can bake bread (breadmaker) through an invertor, run the watermaker and power fridge and small freezer off wind and sun power. Batteries came direct from the manufacturer who are British(although purchased from a supplier), I believe the Lifeline ones are American and all US batteries seem to be about twice the price of what you can get in Britain (we are in the Caribbean), even the lead acid ones. So I don't know if they are a superior product or just more expensive. We have been delighted with ours.
 
Lifeline AGM's are excellent. Against the total cost of the boat the extra cost is minimal. Ours were bought in the US (where our boat is), hence a more realistic price than here, but they are still the most expensive even over there. Worth it though, imho - met many US sailors/liveaboards who swear by them.
 
Can I ask why they are so much better? I have looked at Lifeline's rather poor website, and see the advantages according to them. Many of these appear to offer me nothing, e.g. I don't drop or damage mine before I install them, I don't invert them (I hope!) and they are fully enclosed on my boat, so leakage of acid is not really a problem. The number of charge/discharge cycles that they will take looks useful, but then my wet batteries typically last anything up to seven years and since discovering pulse desulphating I might expect to get more. OK, I need to top up with deionised water, but this year I have only done that twice. So for twice the money, is it really worth it?
 
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We live aboard our boat and bought 3X 200amp Energy batteries in early 2006. So far they have been excellent. We can bake bread (breadmaker) through an invertor, run the watermaker and power fridge and small freezer off wind and sun power

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Does this apply only to AGMs or would you get the same performance from the same size (in amps) in lead acid batteries?
 
True, but on my list of priorities batteries are pretty high and, after a long and thoughtful sensitivity analysis, umm, well, a couple of hundred extra bucks spread over a good number of years seems like a good tradeoff, n'est-ce pa?

We took the good batteries, omitted a TV and DVD (for example) net cost on budget = zero.

You may have different priorities, I only offer my personal opinion on this.
 
Viv - one of the things stopping me buying AGM is that they apparently take longer to charge....... On a boat I would have thought that was a reason not to buy.....
 
Chris - what has caused you to believe that AGM Lifeline take longer to charge? The Merlin website states that they have very low internal resistance and that they recharge faster than standard batteries. The Barden website makes similar claims for them.

Like Richard, I am considering buying the AGM Lifeline for my new boat and for me speed of recharge is a big consideration.

Max
 
I can see some sense in AGM's if they are going to get neglected, left all winter without charging for example and if you have inadequate onboard charging but live in a marina berth all week. For a liveaboard they dont seem to make sense. Compaired to flooded cells you get:

Higher cost
Less cycles (a lot less £ for £)
Longer charge times, they are faster on bulk charge but much slower on the final 20% due to volage limits and therefore more likly to get sulphated
Can't be used with a fast charger
Cant be maintained or topped up
Can't check cell state with a hydrometer
Are terminally dammaged by any overcharging
Don't survive being run flat any better than anything else

They do seem to be the 'in thing' to fit but I can't see why?
 
Are you asking why AGM rather than Lead-Acid or why Lifeline AGM rather than any other AGM?

If the former, well, our boat came with AGM's as standard so we stuck with them when we increased the battery bank - we already had a modern multi-stage charger installed. If they'd been lead-acid I would have changed them anyway because a) I can eliminate one little bit of maintenance (top up) b) I eliminate one little extra worry (acid spill) c) AGM's are mechanically stronger than lead acids (the gel mat supports the plates inside the battery so they can take more pounding and vibration before the battery internals start to break). They can also work at all angles and even submerged, if that's of importance to you /forums/images/graemlins/smile.gif I thought this was quite a useful attribute for a battery to have on an ocean-going sailing boat. All in all they are just mechanically stronger and chemically safer as well as being electrically better than lead acids. All the reports I read at the time and the people I polled left me in no doubt this was the way to go - the downside was cost but as I said before in the big picture it was lost in the noise.

If the latter then there are a few other good ones, Deka are not bad and cheaper than Lifeline, not quite as solid perhaps, Mastervolts looked very good on the reports I read but in the US they were more expensive than Lifeline (perhaps not the case here, haven't checked). Practical Sailor (I think) did a tear down of batteries and compared cheap with expensive to see if there was a difference internally - there was, there was in general a lot more metal and *stuff* inside the expensive ones and they were much more robust = longer life. You get what you pay for I guess. i don't know if I can find their report, it was a couple of years ago.

Just imho.

BTW I think a Group 27 100AH Lifeline was around $200-220 when I was buying (early 2006), Deka's were $140 or so. I notice they cost those figures in £ here, *plus* VAT...
 
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Cant be maintained or topped up
Can't check cell state with a hydrometer
...

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This is the whole point - you don't need to

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Absolutly not, if you charge any lead acid battery slowly enough and are very carful never to overcharge it then you wont use any water - doesn't make any difference whether its a gell electrolite or liquid. Because in a practical instalation that would be imposible there is a recombinant system on AGM's that does alow the cell to gas very slightly without loosing water. If you ever exceed this then it losses water and being a relitvely starved electrolite the cell will quickly die. This system make the cell useable but is why they are restricted to about 14.3v max charging voltage and why you must be very careful not to overcharge. The result is that as the battery approached about 85% charged then the charge current drops drasically which makes it very difficult to FULLY charge an AGM from an alternator even though thay have an initially higher charge acceptance rate. So you need a low level long term charger such a solar or shore power, without this they will sulphate and die reletively quickly. Also if you use a seperate alternator controller, even one set to AGM voltages then running the engine with a fully charged battery (ie leaving the dock after being on shorepower) means that it will go through a charge cycle that the battery doesn't need. This doesn't matter with a wet cell but if done regularly will fry an AGM. In fact most of the things that lead to a little maintaince on a wet cell simply kill a sealed cell - so no they don't need maintainance, just burial!

Don't get me wrong I'm not 'anti' AGM's I have used them for years and for a start batt on a rib or jet ski that might get dunked or turned over they are perfect. Also for a cruiser with a basic charge system used at weekends and hooked up to a pontoon supply during the week they would be OK if a bit expensive. I just find them compleatly the wrong way to go for liveaboard where you want really robust batteries with max cycle life and able to recover from the odd bit of abuse.

If you really want the ultimate liveaboard system it has to be NiCad (Industrial power cells not the liitle AA one in your torch). 100% duty cycle, in fact running them dead flat occasionally improves them! so you only need half the bank size. They take huge charge and discharge currents with no drop off so you can fully charge in much shorter times (about 1/2 times for lead acid) and run massive inverters. They don't sulfate at all, you can store them dead flat all winter or keep on only half charging them for as long as you like with no damage. They have a normal working life of well over 20 years (normaly come with a 10-20 year warrenty) and are totally reliable (hence there normal use is emergency power back up for things like operating theaters and the military) The only probelm is an average size bank for a boat is about 12-1500 pounds and they are about 15% bigger and heavier than an equivilent lead acid set up. Still the idea of an indestructable, maintainace free, spill proof power pack that would last the rest of my sailing life is tempting...
 
That's the conclusion I came to. For most liveaboards especially in warm climes or who have very long periods at sea under power, the ability to top up with water is essential.
 
I have a domestic bank of eight 110 ah Deka AGM´s, fitted last year, seem to be fine so far and they do get a hammering on here, although, I never discharge them below 50%, before re-charge, about once every two days. No sign of loss of capacity sop far, but we´ll see in ablout four more years. Smart mains charger and smart alternator controller. My engine start, 4 x 110, are sealed liquid acid ones, which have lasted six years so far, but are only used for engine start, again no significant sign of loss of capacity.
 
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Higher cost
Less cycles (a lot less £ for £)
Longer charge times, they are faster on bulk charge but much slower on the final 20% due to volage limits and therefore more likly to get sulphated
Can't be used with a fast charger
Cant be maintained or topped up
Can't check cell state with a hydrometer
Are terminally dammaged by any overcharging
Don't survive being run flat any better than anything else


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Are you talking about LIFELINE AGMs or the cheaper copies? Try running your negatives past James at Merlin - he'll put you right.

The great thing about Lifeline AGMs is that they can take as much current overcharge as you can throw at them. Don't know why.
 
I was told AGM's in general can be run lower and will be charged higher (normal wet cells can only be charged to around 80% capacity under normal conditions, AGMs go to 90ish%)

Agree - speak to Merlin - they were very knowledgeable about batteries in general. Per your list he suggested for Lifeline's:

More cycles
Quicker charge acceptance
Lifeline's website says to treat them like Wet Cell batteries re charging
Very hard to overcharge them
Can be run flat and left flat for upto 30 days without any damage.

In addition to this - can be mounted in any orientation (so wouldn't leak acid everywhere during a knock down), take a higher charge, have a 5 year warranty.

I have bought Lifelines (not delivered yet - waiting for the boat to be launched next year and then getting them delivered) - got a good rate from Merlin at SIBS (£160 each for 110ahr)

You pays your money, you takes your choice .....

Jonny
 
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