AGM vs deep cycle

pessimist

pessimist

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Time to replace the house batteries. We do not use the house batteries for engine start purposes. We spend a lot of time on the boat during the summer and charge with wind/solar with generator and sterling smart charger as backup. We tend to use the refrigerator full time and moderate use of pressure water/pcs/tablets etc. When not on board we have several low drain items on permanently. Over the winter we are usually on mains power.

Question is should we go for something like https://www.batterymegastore.co.uk/...s/hankook-leisure-batteries/hankook-dc31.html or pay somethhing like twice the price for AGMs.

Confused of Exmoor
 
If i was fitting SLA batteries i'd fit these ; https://www.batterymegastore.co.uk/hankook-xl31-leisure-battery.html

For AGM, i'd probably fit these ; https://www.batterymegastore.co.uk/brands/hankook-batteries/hankook-ax31-950.html

You could look at deep cycle Trojans, but then you are facing a £600 bill.

At the moment, i'm using 3 of the XL31s, they work well and my solar panels mean that i very rarely have to use the mains charger or run the engine during the Summer. If i was buying new today, i might consider the AGMs.
 
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My use is similar to yours. I have Trojan T105s which are now 10 years old and still going strong.
 
You could also consider these:

https://proinsosolar.com/sagm-06-220.html

True deep cycle AGMs batteries.

I ordered 4 at approx £165 plus VAT each, Proinso quoted over £100 for pallet delivery, I arranged my own at approx £55.

Expensive initial cost, and more work involved arranging your own delivery, but (for AGMs) I couldn't find much else that gives 1,700 cycles at 50% DOD & a 10 year warranty, I couldn't find them stocked elsewhere in the UK.
 
I am also in the process of changing my batteries but have opted for low tech approach.

Current battery set up is 3 x 100 amp wet lead acid car batteries combined house and starter pack. They have been in the boat for nine years and still appear to be fine.

They are charged by alternator and solar panels and require only one charge from a charger at the start of the season after having been left all winter.

The reason for changing is that I have experienced how quickly a battery can die at the end of its life and I don't want to be caught out.

I'm in Holland and it seems that only batteries over 100 amps are now available as wet cell, so I have bought 2 x 190 amp wet cell batteries. They cost the equivalent of £370.

The reason for sticking with wet cell batteries is that, if they have been overcharged, the electrolyte can be topped up. With Sealed and AGM batteries, overcharging results in death of the battery. I also do not need sophisticated ( expensive ) charging systems to ensure longevity which means less electronics to go wrong.

I am a firm believer in the KISS principle!
 
pessimist said:
Question is should we go for something like https://www.batterymegastore.co.uk/...s/hankook-leisure-batteries/hankook-dc31.html or pay somethhing like twice the price for AGMs.
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With ordinary "sealed" maintenance-free batteries, the secret to long life is not to discharge them excessively. So it's cheaper in the long run to buy an extra one or two batteries and create a large battery bank. On my old boat, I used to get at least 8 years out of a set of maintenance-free batteries. They have a large reserve of electrolyte - I cut a hole in one when the "green eye" indicator went black, and found that the plates were still well covered.

I quite like AGM batteries, which I have on my current boat, they are theoretically much less prone to internal short failures, they are clean, and they can accept high charging rates. And they're not twice the price!

Either type would do the job for you. But I reckon that adding an extra one or two batteries to your bank is one of the best investments you can make.
 
EFB technology seems to be the order of the day .. even the car manufacturers are moving from AGM to EFB.

Simpler charging regime than AGM and good results from the "motorhome" brigade.
 
Graham376 said:
Yes but, adding extra batteries without the ability to charge them fully, will shorten battery life so, it's important to weigh up charging regime as well.
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+1

Lots of solar is a game changer with a decent size of battery bank. You can get 90%-95% SOC every morning and back to 100% the same day. The small drop in SOC means you aren't cycling much and even cheap batteries will last quite a while.

One big problem with lead/acid batteries is the rapid drop in charging efficiency as they get to the upper SOC range. The bigger your bank the higher the SOC each morning and the less efficient the charging. Getting a sweet spot is the trick. A huge bank is expensive and a waste if never actually used.

I seem to manage with 450AH and 355W panels (+plus an extra roving flexible for late in season). Batteries tend to be in 88%-94% each morning, depending on usage in previous night (fridge loading, TV etc.).
 
From experience if you want something that will really last (probably well over ten years) and stand up to some accidental abuse then opt for Lifeline. They may be more but they really are the gold standard of the AGM world.
 
Thanks everyone. Can't really justify the cost of Trojans (nor do I have the space in the battery compartment) so decided to go for the low tech (and cheap) advice from Paul Rainbow. Also take PVB's point about extra battery capacity. Maybe I'll have to take a look at expanding the battery compartment.
 
pessimist said:
Thanks everyone. Can't really justify the cost of Trojans (nor do I have the space in the battery compartment) so decided to go for the low tech (and cheap) advice from Paul Rainbow. Also take PVB's point about extra battery capacity. Maybe I'll have to take a look at expanding the battery compartment.
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Posts #11 and #12 also raise good points. If you fit fit enough solar to last a day or two of poor weather, that makes a big difference. On sunny days your batteries should get to 100% and the panels will keep up with your loads.
 
Quick update. When paying by PayPal the £15 delivery charge is not made obvious until payment confirmation has been made. Battery Megastore then emailed me this morning to announce that the batteries were not in stock.
Battery Megastore are off my Christmas Card list.
 
ip485 said:
From experience if you want something that will really last (probably well over ten years) and stand up to some accidental abuse then opt for Lifeline. They may be more but they really are the gold standard of the AGM world.
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I've just changed my 5 Lifeline AGMs for 5 Exide AGMs. As the combined cost of the Lifelines would have been around £3000, compared to the Exides at around half that, it seemed a no brainer really. :(

Richard
 
pessimist said:
Quick update. When paying by PayPal the £15 delivery charge is not made obvious until payment confirmation has been made. Battery Megastore then emailed me this morning to announce that the batteries were not in stock.
Battery Megastore are off my Christmas Card list.
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That's disappointing, i've always had very good service from them. I looked at the Paypal payment and you're right, no mention of the delivery charge, even up to the point when you hit the "Pay" button, that's not good, i'd complain to them and Paypal. As for being out of stock, looks like there was an error in their stock control system, they are now showing as "Out of stock".
 
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