AGM Batteries vs. Cheap 'Leisure' Batteries

[Patrick_C]

I know this may have been discussed before across (many) different threads and other places but I am finding contradictory information and advice ...

I currently have 3 x 110Ah Leisure batteries (Sealed Lead Acid 'Maintenance Free' type) which are charged from the alternator (60A), a Sterling 40A charger, and a 200w solar panel.  The starter battery is on its own alternator but is also linked from the leisure batteries via a battery maintainer.  Most of the time I have been on hookup and the leisure batteries have  lasted a couple of years without any problems but recently their performance has tailed off especially when out and about.  The boat is set up to be relatively 'low power' - there's a 1600W inverter which is used to run bigger things and the rest is lights/pumps/chargers etc.

As I want to cruise more frequently and for longer I'm thinking about replacing these with something more durable.  Various sources are pointing towards Victron AGM batteries as simple replacements, although Trojan 12V or 6V are an option too.

The points where I find contradictory advice:

1. People seem keen to sell me AGM batteries (e.g. Victron) as drop-in replacements for the existing leisure batteries but Victron's own info suggests AGM => starter batteries; Gel => home batteries.  Gel seem hard to come by in any case.   Are AGM's going to do the job of home batteries adequately?
2. Given that when cruising the main means of charging will be the alternator, will this be a problem?  My reading of various docs. and posts is that it is for Gels, but  they are not clear about AGMs (if these are even a good idea as home batteries - point 1)
3. Would I be better off going for Trojan batts instead - and if so, are the 12V's any good?  I have measured up by battery tray and the 6V ones will be difficult to fit in

Or should I just keep life simple and buy cheap 'leisure' batteries again?  I appreciate that every system and setup is different but I can't be the only person in this situation, but I do get the feeling that there is a lot of hard sell and vested interests at work in the advice I've read elsewhere ...

Just to clarify, given other discussions about 'Smart' Alternators that mine (attached to a Beta 38) is a 'Stupid' Alternator.

Edited August 26, 2017 by Patrick_C

[Tony Brooks]

Be aware that on AGM supplier happily states that they need a higher charging voltage so your alternator might need adjusting but as many/most alternators are no adjustable for charging voltage and some may need a new component when pressed said they recommend that you spend another £200 ish on top of the batteries' cost for an add on. Not Victron I hasten to add.

I would say that as you are altering your usage and charging pattern it ma be best to stick with cheaper batteries until you are sure you are monitoring and charging them properly. Once you have that sorted you an buy expensive ones with some confidence you will not wreck them

 

 

[cuthound]

Yes, stick to leisure batteries until you understand and can stick to a sound battery charging regime and can make them last 

Only then consider changing to Trojans or AGM's.

My boat is still on its original fit Lifeline AGM's and is 10 years old.  However they have lost about 40% of their capacity in that time.

[mrsmelly]

7 hours ago, Patrick_C said:

I know this may have been discussed before across (many) different threads and other places but I am finding contradictory information and advice ...

I currently have 3 x 110Ah Leisure batteries (Sealed Lead Acid 'Maintenance Free' type) which are charged from the alternator (60A), a Sterling 40A charger, and a 200w solar panel.  The starter battery is on its own alternator but is also linked from the leisure batteries via a battery maintainer.  Most of the time I have been on hookup and the leisure batteries have  lasted a couple of years without any problems but recently their performance has tailed off especially when out and about.  The boat is set up to be relatively 'low power' - there's a 1600W inverter which is used to run bigger things and the rest is lights/pumps/chargers etc.

As I want to cruise more frequently and for longer I'm thinking about replacing these with something more durable.  Various sources are pointing towards Victron AGM batteries as simple replacements, although Trojan 12V or 6V are an option too.

The points where I find contradictory advice:

1. People seem keen to sell me AGM batteries (e.g. Victron) as drop-in replacements for the existing leisure batteries but Victron's own info suggests AGM => starter batteries; Gel => home batteries.  Gel seem hard to come by in any case.   Are AGM's going to do the job of home batteries adequately?
2. Given that when cruising the main means of charging will be the alternator, will this be a problem?  My reading of various docs. and posts is that it is for Gels, but  they are not clear about AGMs (if these are even a good idea as home batteries - point 1)
3. Would I be better off going for Trojan batts instead - and if so, are the 12V's any good?  I have measured up by battery tray and the 6V ones will be difficult to fit in

Or should I just keep life simple and buy cheap 'leisure' batteries again?  I appreciate that every system and setup is different but I can't be the only person in this situation, but I do get the feeling that there is a lot of hard sell and vested interests at work in the advice I've read elsewhere ...

Just to clarify, given other discussions about 'Smart' Alternators that mine (attached to a Beta 38) is a 'Stupid' Alternator.

Always cheap, cheerful, bin. Here endeth the lesson. Amen

[Guest]

35 minutes ago, cuthound said:

Yes, stick to leisure batteries until you understand and can stick to a sound battery charging regime and can make them last 

Only then consider changing to Trojans or AGM's.

My boat is still on its original fit Lifeline AGM's and is 10 years old.  However they have lost about 40% of their capacity in that time.

I agree with Cuthound, get used to monitoring batteries then change if that suits you. I have just replaced our old AGMS, which had 10 yrs of liveaboard off shoreline use with another set of AGMS, without hesitation. 

[nicknorman]

We'll just to add balance, we had two sets of cheapo leisure batteries. Both were rubbish and significantly losing capacity after 6 months. We bought Trojans more than 4 years ago and they remain perfect with the original capacity (and I have the means to measure that). I would never go back to cheapo leisure batteries.

However, as said you need to know how to look after your batteries (mostly about fully charging them) because if you don't, you will ruin the batteries in quick time regardless of whether they are cheap or expensive. I certainly wouldn't buy AGMs or Trojans if I didn't have adequate monitoring equipment, know the specific charging requirements and have the ability to charge accordingly.

[mrsmelly]

6 minutes ago, nicknorman said:

We'll just to add balance, we had two sets of cheapo leisure batteries. Both were rubbish and significantly losing capacity after 6 months. We bought Trojans more than 4 years ago and they remain perfect with the original capacity (and I have the means to measure that). I would never go back to cheapo leisure batteries.

However, as said you need to know how to look after your batteries (mostly about fully charging them) because if you don't, you will ruin the batteries in quick time regardless of whether they are cheap or expensive. I certainly wouldn't buy AGMs or Trojans if I didn't have adequate monitoring equipment, know the specific charging requirements and have the ability to charge accordingly.

I don't doubt you at all but I thought you were in a marina plugged in most of the time? I get at least two years completely off grid from my cheapo leisure batts and I don't play at it mine are in use 24/7 365. They of course do not have the same capacity throughout their lifespan as that diminishes slowly day by day I suppose until I change them usualy 2/2 and a half years on. What did you do to kill yours in six months especialy when you have a travelpower for the hard work?

[rusty69]

1 minute ago, mrsmelly said:

What did you do to kill yours in six months especialy when you have a travelpower for the hard work?

Run electric kettles, coffee makers and all manner of things its not sensible to run from a battery bank made up of cheap leisure batteries 

[mrsmelly]

2 minutes ago, rusty69 said:

Run electric kettles, coffee makers and all manner of things its not sensible to run from a battery bank made up of cheap leisure batteries 

But Nick has travelpower as do I so the batteries never do any hard work?

[rusty69]

1 minute ago, mrsmelly said:

But Nick has travelpower as do I so the batteries never do any hard work?

You run your engine to boil a kettle for morning coffee? 

[mrsmelly]

1 minute ago, rusty69 said:

You run your engine to boil a kettle for morning coffee? 

No I use the gas stove only a numpty would have an electric kettle on a boat  they are completely pointless. I am just wondering how Nick killed his batteries so quickly when he has Travelpower because the whole point of the thing is you turn it on when using any heavy leccy using device thereby not adversely effecting the batteries.

[rusty69]

Just now, mrsmelly said:

No I use the gas stove only a numpty would have an electric kettle on a boat  they are completely pointless. I am just wondering how Nick killed his batteries so quickly when he has Travelpower because the whole point of the thing is you turn it on when using any heavy leccy using device thereby not adversely effecting the batteries.

Bet he don't run the engine to make the morning toast and coffee! 

Nick? 

[mrsmelly]

2 minutes ago, rusty69 said:

Bet he don't run the engine to make the morning toast and coffee! 

Nick? 

As well you know on a boat he will use a gas cooker to heat the water for the coffee and the gas grill for the toast like the rest of us  stop tying to wind him up

[rusty69]

8 minutes ago, mrsmelly said:

As well you know on a boat he will use a gas cooker to heat the water for the coffee and the gas grill for the toast like the rest of us  stop tying to wind him up

Ah, come on, not just a bit? 

[cereal tiller]

12 minutes ago, mrsmelly said:

No I use the gas stove only a numpty would have an electric kettle on a boat  they are completely pointless. I am just wondering how Nick killed his batteries so quickly when he has Travelpower because the whole point of the thing is you turn it on when using any heavy leccy using device thereby not adversely effecting the batteries.

Me am Numpty?My Boat has a 770 Watt Kettle for when the Boat is off Grid,tha Battery Bank does not seem to mind.

[mrsmelly]

1 minute ago, cereal tiller said:

Me am Numpty?My Boat has a 770 Watt Kettle for when the Boat is off Grid,tha Battery Bank does not seem to mind.

Yes but we already know you are a numpty

[cereal tiller]

5 minutes ago, mrsmelly said:

Yes but we already know you are a numpty

Oooh! Better than a Grumpty I 'spose

[mrsmelly]

1 minute ago, cereal tiller said:

Oooh! Better than a Grumpty I 'spose

I resemble that remark

[rusty69]

Think I will call our next boat The Grumpty Numpty. 

 

[cereal tiller]

11 minutes ago, mrsmelly said:

I resemble that remark

Resemble?Victor Meldrew was inspired by your Mammoirs(delib.)

[rusty69]

3 minutes ago, cereal tiller said:

Resemble?Victor Meldrew was inspired by your Mammoirs(delib.)

I don't believe that! 

[mrsmelly]

4 minutes ago, rusty69 said:

I don't believe that! 

Me and Vic were drinking buddies

[nicknorman]

When you two've (3) quite finished....

yes we sometimes (quite often) run the kettle from the batteries, but only if we are going to recharge shortly afterwards (eg breakfast sometimes, lunch most times, but rarely evenings). Toaster and coffee machine ditto.

Yes we have a Travelpower but why have a noisy engine running when you're going nowhere?

Anyway, the point is that whatever treatment the cheapo leisure batteries got, the Tojans get too.

I'm sure if you were generally busy knitting the hair shirts and seeking out fresh nettles for the daily flagellation, you wouldn't have any need to discharge your batteries and thus they'd last a couple of years.

Edited August 26, 2017 by nicknorman

[rusty69]

1 minute ago, nicknorman said:

Anyway, the point is that whatever treatment the cheapo leisure batteries got, the Tojans get too.

But maybe not as suited to cope with it, hence their premature demise. 

[mrsmelly]

2 minutes ago, rusty69 said:

But maybe not as suited to cope with it, hence their premature demise. 

 Bless him. But fair enough he did come clean in the  end.