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Alright, as people have noticed, I'm focusing on batteries right now. The 490AH we have right now just isn't enough - 2 kids, 2 laptops, fridge, lots of other energy draining items, and we're not going to change our usage (much). We currently have a battery area that measures 24" x 21.5" x 11" (LxWxH). Any thoughts on the best battery configuration giving me the most amp hours? I just thought I'd post this brain teaser out there for people looking for a late night boat puzzle :)

Chris
 

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Chris, IIRC there are only 3 actual battery makers - all the various products out there are essentially just re branding operations.
at 24 x 21.5 x 11 you can stack 6 of the trojan 6v 125's, wiring them in pairs for 12v. Each is 10 3/8 x 7 1/8 x 10 11/16.
Trojan Battery Company
If my math hasn't failed me that's 750ah worth.

Wiring is going to be a bit of squeeze but should be doable.

They have a 145ah 6v, but it's too tall.
 

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There are several options available with Trojans.

I found some 12 V Trojans that will fit my tray, with a little mod. so take some time to look over all their different configs.
 

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Labatt, have you thought of breaking up your battery banks a bit? Echo-charge a starter battery in the engine bay and echo-charge a windlass battery in the anchor locker. Would this affect your "amp count"?

Conversely, you could consider the 200 Ah AGM 8D that are only 5" wide (used in UPS batteries in phone exchanges and server farms). These could be lying on their sides under the floorboards in many boats.

BTW, I agree with your math. I have one kid and likely fewer calls on electricity than on your boat and I am planning for a four 8D or equivalent house bank of circa 840 Ah. My goal is longevity: I want to run the boat on the hook for a week or on passage even if the wind is light or the skies are cloudy. I only want alternator amps as a byproduct of actual motoring, which we would likely do to pump the holding tank once a week out beyond the reef, so to speak.
 

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Fitting 5 batteries into a space for 2

I cruised on my 1988 Cal 33 down the Island chain for a couple of years and anchored out everynight. In order to increase my Amp hours I had 1 Large
battery box built from Polyproplene ( welded) to fit my battery area. I found I could fit 5 batteries into the box. They all used the same Battery Box.
Any Plastic Fabricator can do the welding. For the mat'l and welding about $100. It worked Great! Seperate Battery Boxes take up a lot of room.

[email protected]
 

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Bad idea... not ready for prime time as the charging system LiIon batteries require are considerably more sophisticated than what's currently available. Also, the batteries are very, very expensive.

Hi

Consider Lithium Ion batteries. 2 x the charge for 1/2 the weight and size.
As for using one large battery box, the major concern with doing that is holding down all the batteries properly. With individual boxes, it is relatively easy to do. With a single large box, it is much more difficult.

As for Labatt's original question, I'd go with the Trojans suggested, unless you've got cash to spare, since you could probably get a modular Surrette-Rolls setup with the individual 2 VDC cells that would provide more power in the same space. :)
 

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No, that sounds right. The 6v to 12v calculation strikes again.

Anyone else using the Surrette "modular" system? It has some upsides in terms of not killing yourself getting the batteries out, but it creates more failure points, I think.
 

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Anyone else using the Surrette "modular" system? It has some upsides in terms of not killing yourself getting the batteries out, but it creates more failure points, I think.

Yes using the Surrette/Rolls 2v cells. System works as advertised.

It does not have additional failure points as every battery has those same connections but internal to the case instead of external.

The only downside to this system is you pay a premium for the batteries but they do offer extended life when compared to most. Also make sure you get the 'hydrocaps' they really reduce water consumption.

You can also get them without the outer case which frees up room for more cells if that buiys you anything.
 

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IIRC, the Trojan T125 has more capacity than the T105, and the T105s are rated at 225 amp-hours, so six of them would be 675 amp hours, not 375... and the T125s would be a bit more, probably 725 or so.

Am i missing something, 6 trojan 6v 125's is only 375 amp hours @12v
 

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Looks like I'll be going Mastervolt... they make slimline AGMs (not the new TPPL technology) that are 200AH each. I can fit 4 in our current box for a total of 800AH. I'll also be replacing our current Freedom 15 charger/inverter (75AH charger) with a Freedom 30 (up to 140AH charger) or a Freedom 25 (up to 130AH charger). I'll have to play with the charging amperage to make sure I don't overload anything, but I'll have a little more charge capacity, and the footprint is the exact same (although I'll be upgrading some of my battery cabling).
 

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Just curious, how much are the Mastervolt AGMs??
 

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Ridiculously expensive. It looks like I'll be able to get them for about $550 each, but I really want the extra amp hours and not have to expand our battery box. It's that important.
 

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Looks like I'll be going Mastervolt... they make slimline AGMs (not the new TPPL technology) that are 200AH each. I can fit 4 in our current box for a total of 800AH. I'll also be replacing our current Freedom 15 charger/inverter (75AH charger) with a Freedom 30 (up to 140AH charger) or a Freedom 25 (up to 130AH charger). I'll have to play with the charging amperage to make sure I don't overload anything, but I'll have a little more charge capacity, and the footprint is the exact same (although I'll be upgrading some of my battery cabling).
Check these batteries also, you should be able to fit in 3 or 4 of the 210's.
Meridian AGM

Paul L
 

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Not what you originally posted, but what about putting another battery somewhere else and connecting it in.

Trying to think outside the (battery) box.
 

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Valiente-
Using individual 2v cells and bolting them up is in fact the worldwide standard for the batteries used in electric fork lifts and other industrial applications. It is the only way to assemble a huge battery and still have a way for one or two men to lift the pieces by hand, and it is a proven economy since individual cells can be (and are) replaced if one cell fails.
When you think about it, it has the same number of failure points as any 12v battery which has been assembled--and then sealed out of reach in a case. But, with individual cells you can at least access the connections.

Of course, you can't ust hop down to the local chandlery to buy the cells, or get warranty service on them. But there's a fork lift battery supplier in just about every commercial port in the world.
 

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Am i missing something, 6 trojan 6v 125's is only 375 amp hours @12v
Two T-125''s wired in series for 12V will supply 240amp hours @ the 20 hour rate. Six of these wired in series/parallel gives you 720 amp hours..

In series = Double voltage / amps stay the same

In parallel = Double amps / volts stay the same
 

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Ridiculously expensive. It looks like I'll be able to get them for about $550 each, but I really want the extra amp hours and not have to expand our battery box. It's that important.
Labatt,

I am looking at these batteries as well but they seem to be hard to find.

May I ask where (retailer) you are going to buy them?

MaineSail,

Should that be:

Wired in series = double voltage, half the amp?

Cheers
 

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MaineSail,

Should that be:

Wired in series = double voltage, half the amp?

Cheers
If we are talking about the face value ratings of just one battery no, if you are talking about two batteries yes..;) I was referring to the face value ratings of one 6V battery.

When you wire two of them in series, and use the face value ratings of one six volt battery, the voltage goes from 6 to 12 but the amp hour rating stays the same.

If using two batteries for your basis the voltage doubles in series from 6 to 12 and the amp hours are cut in half..

Apples & oranges both are correct.:)
 
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