Replacing Lifeline AGM Batteries

[wingman]

Time to replace my Lifeline AGM batteries,  2 GPL-4dl house and a GPL1400t engine start.

Deka and US Battery have been recommended as less expensive but solid alternatives.

Any experiences with these batteries or other options to consider?

[steveg]

Wingman, I made those AGM batteries were I worked for several years and they are very good.  The downside of 4DL batteries is the cost and weight (about 120 lbs). A better alternative are 6v Golf batteries as they have less weight per battery and more amp hours. I had the 4DL but changed to the 6V and made it easier. I would suggest your get the most amp hour batteries that you can fit.

[Jim Hardesty]

Shamrock has the OEM setup with 2 4D batteries.  I get 5-7 seasons from the Deka batteries, change them when I can't get 3 days/night at anchor, ie no charging, running fridge, lights, keurig coffee maker and microwave.  If I spent every night at a dock could probably get a few more seasons.
Check your charger that you can set/program to standard wet cell batteries.
What I understand the advantage of AGM batteries is that they will accept a charge faster.  Is that important to you? 
There is always a lot of discussion on batteries and how to setup and use.  IMHO is that it really depends on how you use your boat.  Do you sit on a mooring or at a dock with shore power.  Can you sail quickly or do you need to motor to go sailing.  and more considerations.
Jim

[Stu Jackson]

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What I understand the advantage of AGM batteries is that they will accept a charge faster.  Is that important to you? 
There is always a lot of discussion on batteries and how to setup and use.  MHOP is that it really depends on how you use your boat.  Do you sit on a mooring or at a dock with shore power.  Can you sail quickly or do you need to motor to go sailing.  and more considerations.
Jim

Jim's right.

But I would cut to the chase:  the significant drawbacks of AGMs is that they DO NOT TOLERATE PSOC.  At all.

There are a couple of AGM links by Maine Sail in the Electrical Systems 101 that you should read.

[wingman]

thanks guys, but what is PSOC?

[Noah]

It is either " Philharmonic Society of Orange County (Irvine, CA) or "Partial State of Charge" you decide.

[wingman]

 

[Ron Hill]

Wing : The other advantage of AGM batteries is that they don't self discharge (if you happen to be on a mooring w/a solar dribble charge).  They are also maintenance free (sealed)

If I had a MKII C34 at first battery change out I'd get rid of the 4D size battery (bad back!!) and go to the 6V golf carts (if you need that kind of battery amp hours)

A thought

[Stu Jackson]

Wing : The other advantage of AGM batteries is that they don't self discharge (if you happen to be on a mooring).
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While that may be true, what it also means is that unless they are fully charged they will be in a PSOC and will have a short life.  And, if you're on a mooring, you should definitely install solar to keep whatever kind of batteries you have healthy.

[MarcZ]

Firefly AGM batteries are not affected by PSOC and 3 of these will fit in C34 battery compartment

[Noah]

Mark- How many amps are the combined bank of three Fireflies?

[waughoo]

Patches just updated his battery bank to firefly batteries and he is quite happy with the results.

[MarcZ]

With 3 x 116 Ah (@ 20h)   I have  348 Ah and can use 70% without killing the battery life.

Be ready to upgrade your charging setup,  120A charger would be desirable.

[Admiral_Swellson]

I'm currently in the process of replacing 4x 6v 175ah (4x 62 lbs = 248 lbs) Powertron's (Trojan) with a single 300ah Lithium (72lbs). This is in conjunction with 2x 200w solar, and a 3000w inverter charger. Looking to be off-grid capable for a 10 days to couple weeks. I guess water will be our Achilles heel, but we can dinghy for that.

[mainesail]

I'm currently in the process of replacing 4x 6v 175ah (4x 62 lbs = 248 lbs) Powertron's (Trojan) with a single 300ah Lithium (72lbs). This is in conjunction with 2x 200w solar, and a 3000w inverter charger. Looking to be off-grid capable for a 10 days to couple weeks. I guess water will be our Achilles heel, but we can dinghy for that.

Be sure that battery meets ABYC, most do not, and definitely be sure the BMS can handle a 3kW inverter plus the surge.. Also be sure you fully understand how to deal with a BMS load dump.. Lot of sleazy LiFePO4 vendors out there will tell you these are "drop-in" replacements...