Agm/lead acid batteries

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robertj

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I'm in the midst of replacing my service bank of batteries due to failure of both of them at once.
My set up is three alphaline 125amp/hr., consisting of two house bank and one starter for the Bukh 24.
the starter battery is only one season old.
I'm thinking of replacing the two house batteries with AGM type.


Will this mixing of sealed wet cell and AGM be unsatisfactory regarding charging etc?
I wish to keep the starter battery as its nearly new.
 
Assuming you have separate charge outputs to each bank this would be just fine, but check if the AGM requires different charger settings.

Personally I wouldn't bother with AGM. There was an excellent thread on here a few months ago where the advantages never offset the cost - I will see if I can find it.


No sorry can't find it, but plenty of other threads on this subject - just search Battery or Deep Cycle, etc.
 
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I had a smart charger that you could set to charge different types of battery. For house battery(s) use deep cycle batteries such as lead acid Trojans I had two 6 volt T105's wired in series there is a Trojan 12 volt version. For starting use a cold cranking AGM battery as used in cars. Trojans last 5 years, longer than normal batteries.
 
robertj said:
Will this mixing of sealed wet cell and AGM be unsatisfactory regarding charging etc?
I wish to keep the starter battery as its nearly new.
Click to expand...

Typical modern alternator voltage is around 14.4v, which is fine for AGM, open cell or sealed lead acid. If you have a good main charger or solar controller that has multiple charging profiles, choose one that will suit both types.

However, i agree with superheat, hard to justify the extra cost. I also find it hard to justify the cost of Trojans. I recently purchased three Hankook XL31s from Battery Magastore and am happy with them. 130ah for less than £100 each.
 
KellysEye said:
I had a smart charger that you could set to charge different types of battery. For house battery(s) use deep cycle batteries such as lead acid Trojans I had two 6 volt T105's wired in series there is a Trojan 12 volt version. For starting use a cold cranking AGM battery as used in cars. Trojans last 5 years, longer than normal batteries.
Click to expand...


I have a charger that can be set to different profiles, but it cannot be set to charge more than one profile at once. Not that it needs to, there are profiles that suit any combination of AGM/sealed/open lead acid.

As for his engine battery, he's already said he want to keep it, but if he didn't i cannot see why he'd want to fit an AGM to start his engine.
 
KellysEye said:
I had a smart charger that you could set to charge different types of battery. For house battery(s) use deep cycle batteries such as lead acid Trojans I had two 6 volt T105's wired in series there is a Trojan 12 volt version. For starting use a cold cranking AGM battery as used in cars. Trojans last 5 years, longer than normal batteries.
Click to expand...

+1 Trojans are the best IMHO, the extra outlay for a pair giving you some 250ampH and 12v are designed to take a lot of abuse, (used in golf carts can take rapid discharging and recharging) and come back smiling, also some reports from liveaboards lasting 8 or more years.
 
KellysEye said:
I had a smart charger that you could set to charge different types of battery. For house battery(s) use deep cycle batteries such as lead acid Trojans I had two 6 volt T105's wired in series there is a Trojan 12 volt version. For starting use a cold cranking AGM battery as used in cars. Trojans last 5 years, longer than normal batteries.
Click to expand...
My Numax 110 ah are near enough 8years old, bought from a farmers depot in Oswestry, they use them for electric fences, still going strong. Although "sealed" you can unscrew the cell tops, which I do yearly and top them up. Why pay Trojan prices?
Stu
 
Sarnia said:
+1 Trojans are the best IMHO, the extra outlay for a pair giving you some 250ampH and 12v are designed to take a lot of abuse, (used in golf carts can take rapid discharging and recharging) and come back smiling, also some reports from liveaboards lasting 8 or more years.
Click to expand...

Pair of T105s = 225ah and come with a 1yr warranty

Same money buys me 3x130ah Hankooks with a 4 yr warranty.
 
Daydream believer said:
I would have thought a live aboard would live longer than that. Although I cannot recall the subject of how long live aboards actually do live aboard being discussed on the forum. Do they last for years ?
Do they really peg out or give up sooner?
Click to expand...

Depends if they have an understanding wife, but the batteries do.
 
KellysEye said:
>I have a charger that can be set to different profiles, but it cannot be set to charge more than one profile at once. Not that it needs to, there are profiles that suit any combination of AGM/sealed/open lead acid.

The charger I had that you can set to different types of batteries was: https://www.amazon.com/Xantrex-804-1220-02-TRUECharge2-Parallel-Stackable/dp/B001G7CZRM
Click to expand...

Yes, you can set it to different battery types, but all three outputs will be the same. You cannot, for instance, set it to AGM for output one and open cell lead acid for output two. If different battery types are fitted you choose an output profile that both types of battery can tolerate.
 
My AGMs are now 13 years old and seem fine. I have 2 banks of 2x100ah and 1x100ah charged by a smart charger from shore power.
I keep wondering how much longer they will last though??
 
Habebty said:
My AGMs are now 13 years old and seem fine. I have 2 banks of 2x100ah and 1x100ah charged by a smart charger from shore power.
I keep wondering how much longer they will last though??
Click to expand...

The AGM Lifeline batteries on our previous boat were the origional Island Packet OE's. They needed changing when we sold her last year, but only because their capacity had dropped meaning more frequent charging was required. Only two days on the hook before they dropped below 12.4 volts.

They were 15 years old.

Our newer IP had four new 110AH Lifelines fitted due to neglect. Only one of the old ones was serviceable. That now runs the genset and I added a new one to the house bank.

I hope for good service from them.

I have a Yuasa AGM 24 AH from a computer back up system. From the date mark it is 19 years old. It is still in good working order, hardly ever needs re-charging and jumped started our car when we returned from NZ after 18 weeks away.

I think AGM's are fine.
 
The boat I bought last year had been sitting in a yard in Greece for 2 years with no charging connected. The 4 Lifeline 110Ah AGM domestic batteries that were new in 2012 were completely dead. I could repeatedly charge them up to about 12.8v but it quickly faded away so they had to go. The 24Ah Odyssey engine start battery is still going strong despite being neglected in the same way. I replaced with standard sealed lead acid, partly because that was all that was available at the time, partly on the basis that I can replace them several times for the price of the AGM batteries
 
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