Sorry, yet another what type of battery should I get thread

[jbinbi]

I have 3 140 Ah FLA exides that were OEM equipment with the boat new at the end of 2015. I have 2 80A alternators and 560W of solar. All LED lighting, just Nav, autopilot and fridge used for day sailing and 3-5 day cruising. On a mooring.

My victron controllers show me history, high and low V for the week, and my 'resting' V is currently about 12.6V (I have 2 controllers, one for each panel , in parallel to my Bat, and oddly one says about 12.58 and the other 12.61, I would think since each controller is tied to the battery bank in parallel they should be the same but that is a different story).

Last time out while sailing I turned off the solar panels, had the nav, autopilot and fridge running, and battery v on the not so accurate main electrical panel was at 12..2 or 12.3 with everything running.

Thinking it is time for new batteries. Don't want Li. Not even sure I want AGM, was thinking of just new FLA.

Each battery is currently in a 22"l x 9"w x 8"h case of 140Ah. What is best bang for the buck that will fit. Can I go to more AH than the 420 with my current 2 x 80 A alt and solar setup and reasonably expect to put more A back in? (Catamaran, so I figure if I have to motor for an hour each time I go out, I am get 2 x from it, and am getting 160Ah back in.)

Golf cart batteries, I think they are 220Ah each, can I just get 2 of them and that would replace my entire system here? Not sure where I can get cases to fit them. Also have to try to get the current ones out of the boat;-)

[john61ct]

Yes FLA GCs best bang for the buck

is Duracell (actually Deka/East Penn) FLA deep cycle golf cart batteries, 2x6V, around $200 per 200+AH @12V pair from BatteriesPlus or Sam's Club. Deka labeled same batts also sold at Lowes.

So 2 pair to keep your 400+ Ah capacity, 3 to increase it. Note it isn't the bank size that requires more energy input, as long as your usage does not increase just means a bigger buffer, and shallower DoD greatly increases bank lifetime. At a space & weight cost of course.

12V batts are difficult to get anywhere near as good value, AGM will cost a lot more amortized per year, so I'm mod the box / space if at all possible, give it a bit more room than needed as sizes do vary a bit - go off the Deka EGC2 even if you buy the slightly smaller GC2 version.

Don't buy boxen, just marine plywood and epoxy, battery acid paint on the inside, maybe a sheet metal tray.

Originally Posted by jbinbi

I have 2 controllers, one for each panel , in parallel to my Bat, and oddly one says about 12.58 and the other 12.61, I would think since each controller is tied to the battery bank in parallel they should be the same but that is a different story

0.03V accuracy is pretty good.

If OCD requires a canonical super accurate voltmeter, research the purchase well, put it right at the bank and ignore all others.

[Bill O]

Originally Posted by john61ct

Yes FLA GCs best bang for the buck

is Duracell (actually Deka/East Penn) FLA deep cycle golf cart batteries, 2x6V, around $200 per 200+AH @12V pair from BatteriesPlus or Sam's Club. Deka labeled same batts also sold at Lowes.

So 2 pair to keep your 400+ Ah capacity, 3 to increase it. Note it isn't the bank size that requires more energy input, as long as your usage does not increase just means a bigger buffer, and shallower DoD greatly increases bank lifetime. At a space & weight cost of course.

12V batts are difficult to get anywhere near as good value, AGM will cost a lot more amortized per year, so I'm mod the box / space if at all possible, give it a bit more room than needed as sizes do vary a bit - go off the Deka EGC2 even if you buy the slightly smaller GC2 version.

Don't buy boxen, just marine plywood and epoxy, battery acid paint on the inside, maybe a sheet metal tray.

0.03V accuracy is pretty good.

If OCD requires a canonical super accurate voltmeter, research the purchase well, put it right at the bank and ignore all others.

Excellent reply John!

We are currently running Crown GCs at 235Ah each (940 Ah total for house system) and on year 7 with them. At anchor in the morning w/the fridge running overnight (before any solar input) we are still see resting V at 12.6 or 12.7V. So would agree, they are the excellent bang for the buck.

Our house system is a bit large, but is the combined house/starter/windlass package in 2 banks. This set up has been working well for many years. Will agree w/John, it is nice to have the large buffer capacity as we tend to sit for many days and we easily make it through rainy days w/low solar input. Downside is they are relatively heavy, but our boat is large enough to handle it and the large battery box was designed/positioned in the boat for FLAs technology in mind.

For your Lagoon, 2 pair of GCs would be good replacement for your current 3 FLAs.


Bill O.

[john61ct]

Yes Crown is a great mfg for FLA

Also Trojan, U.S. Battery, Superior

Rolls/Surette at the top.

but all pricier than those EPM. . .

[jbinbi]

Thanks for the replies.

Looking at this GC2, 205Ah for $90. They have one with 220A for $20 more.
https://www.batteriesplus.com/produc...p-gc2/sligc110

Have not found GC1.

I can basically fit 2 side by side in my battery case, they are 2" higher but maybe I just fit the top of the case on. So it would be easy to get 3 sets of 2 in the same space I have now.

Since I need to wire in series, and I don't have a crimper this large, are there ready made cables? I need to go + to - on each set, then neg to neg and pos to pos on each set. Each cable is only like 6 to 12".

[Bill O]

Do you have a Battery Warehouse near you or something like it? If not, find a place that installs auto batteries and they usually have cable that they can crimp up jumpers for you.


Bill O.

[john61ct]

This is the slightly bigger one https://www.batteriesplus.com/productdetails/sligc115

[john61ct]

http://genuinedealz.com for quality wire, brilliantly crimp terminated, custom cut to length.

Measure twice!

[john61ct]

Wiring, put all parallel together first, then join into series.

Food for thought
http://www.smartgauge.co.uk/batt_con.html

[Thumbs Up]

I don't think that your current batteries are bad. 12.3 volts with everything running and no charge source is fine. 12.6 resting voltage is not that bad. You are probably undercharging them. How often do you have to add water? If almost never, then you are certainly undercharging. Also, the mistake in your logic with 220ah golf cart batteries is that the 220ah is for six volts. A pair of them has 220ah @12v. You will need two pairs to replace your current batteries but is a little small for that type of boat. You could probably double your capacity with your current charging sources. My guess is that you can get a few more years off of what you have but if you decide to go cruising you should replace them before you leave.