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mitiempo · 03-06-2012, 10:29

Is it possible that Ted is confusing reserve capacity with AH?

That would make the bank about half the size he thinks it is and actually make more sense.

ka4wja · 03-06-2012, 10:41

Hey, sorry about the confusion (and the thread drift!).....

Yes, my Rolls/Surrettes 12-EHG-375PM's are modular 8D's.....meaning that each of the 2-volt cells (36 lbs each) can be separately carried/installed (which was/is a BIG plus to me...)

Here is the spec sheet from Rolls...
http://www.rollsbattery.com/pdf/12EHG375P.pdf

And, here I detailed my choice/installation....
http://www.rollsbattery.com/pdf/12EHG375P.pdf
(more pricey than Trojan's, yes.....cheaper than Lifeline AGM's, etc...and as a long-time loyal Rolls customer, this is a choice that works well for me and my boat....but probably more than others may wish to get into....)

Ted, again sorry about the thread drift...

Fair winds....

John
s/v Annie Laurie

Rustic Charm · 03-06-2012, 15:18

Hi Everyone. I'll just respond in the one message. Thanks to everyone for your great and speedy input. 'STU', I'll start working on the budgett thingy over the coming couple of days. Thanks for that.

'John', you were almost right on the money. (said I was a novice). I went and checked my photographs and yes, I was quoting 'Reserve' apparently. Not that I know what that means. Anyway, I currently have the following.

Four (4) Type 31TW, amp hours 130 , reserve @ 25amps is 227, They are 'deep cycyle. I'm not sure of the brand, can't quite make it out but they are American with big American flag on them.

Am I correct now in thinking I have 530amps in total? (not 1200).

Yeah, stupid mistake, but I did say I was a novice at this. And now I've looked up the origional notes I took when I inspected the boat my notes say 1200amps, so whether the orgional owner told me that I'm not sure.

If I only have 530amp, and it appears you are all in agreement that I don't need more than that, then this suits me fine as it means I can actually fit the starter battery into the new battery compartment I've made with the house batteries. Much neater job.

During my trip down from Adelaide where I purchased the boat to Tasmania where I live, the house bank was connected to a Dead and odd battery. I'm wondering if that is why my 530 amps (now enlightened) was not holding up over night?

I'll get to work on the budgett planner that Stu provided and get back to you all when I've done that. Will be a couple of days I think to work it all out. Thank you all for your great input. Looks like this discussion has saved me a lot of money and time and future heart ache. .

Ted

Jbaffoh · 03-06-2012, 15:25

Ted,

There are different ways to rate amp hours, and the most common is at the 20-hour rate. There are 130ah Type 31's on the market, but I'm a little skeptical that's what you have. My hunch is your 130's were measured at a different discharge rate. Do you know what rate the 130 figure is based on?

Rustic Charm · 03-06-2012, 15:27

Quote:

Originally Posted by Jbaffoh

Ted,

There are different ways to rate amp hours, and the most common is at the 20-hour rate. There are 130ah Type 31's on the market, but I'm a little skeptical that's what you have. My hunch is your 130's were measured at a different discharge rate. Do you know what rate the 130 figure is based on?

Sorry, that's all I have, I quoted the above off the battery sticker.

Jbaffoh · 03-06-2012, 15:45

The reason I ask is so we can compare apples to apples instead of apples to oranges.

Batteries discharge at different rates depending on the amount of load amperage. If you apply 100 amp load, the measured capacity will be less than if a 5 amp load is applied. Some manufacturers will play with peoples perceptions by advertising capacity based on, say, a 25 hour rate to boost their ah rating over those who advertise capacity based on the conventional 20 hour rate.

Maine Sail · 03-06-2012, 16:09

Quote:

Originally Posted by tedsherrin

Hi Everyone. I'll just respond in the one message. Thanks to everyone for your great and speedy input. 'STU', I'll start working on the budgett thingy over the coming couple of days. Thanks for that.

'John', you were almost right on the money. (said I was a novice). I went and checked my photographs and yes, I was quoting 'Reserve' apparently. Not that I know what that means. Anyway, I currently have the following.

Four (4) Type 31TW, amp hours 130 , reserve @ 25amps is 227, They are 'deep cycyle. I'm not sure of the brand, can't quite make it out but they are American with big American flag on them.

Am I correct now in thinking I have 530amps in total? (not 1200).

Yeah, stupid mistake, but I did say I was a novice at this. And now I've looked up the origional notes I took when I inspected the boat my notes say 1200amps, so whether the orgional owner told me that I'm not sure.

If I only have 530amp, and it appears you are all in agreement that I don't need more than that, then this suits me fine as it means I can actually fit the starter battery into the new battery compartment I've made with the house batteries. Much neater job.

During my trip down from Adelaide where I purchased the boat to Tasmania where I live, the house bank was connected to a Dead and odd battery. I'm wondering if that is why my 530 amps (now enlightened) was not holding up over night?

I'll get to work on the budgett planner that Stu provided and get back to you all when I've done that. Will be a couple of days I think to work it all out. Thank you all for your great input. Looks like this discussion has saved me a lot of money and time and future heart ache. .

Ted

Ted,

That is just as I suspected in our PM's you were confusing reserve minutes/capcity with Ah. Your batteries may be imported US Battery 31TMX-XC's. To my knowledge there are very few group 31's rated at 130Ah a the 20 hour rate. The Trojan SCS225 and the US Battery 31DCXC are two of them. The reserve minutes on the 31TMX-XC are 227 @ 25A and 130Ah at the 20 hour rate.

US Battery 31TMX-XC

That is still a large bank for a 34 footer but provided all the batteries are the same age, not mixed with any older ones, it can be a workable bank provided your charging system is up to the task.

Rustic Charm · 03-06-2012, 16:19

That's It Pete, that's my battery. My understanding is that all four are about 18 months old.

So, your opinion would be that I have plenty without buying any more?

I have a few dollars at the moment. Would you recommend I get the stirling Alternator regulator for my system then? They are $199 in Australia.

Ted

Rustic Charm · 04-06-2012, 06:22

Quote:

Originally Posted by tedsherrin

That's It Pete, that's my battery. My understanding is that all four are about 18 months old.

So, your opinion would be that I have plenty without buying any more?

I have a few dollars at the moment. Would you recommend I get the stirling Alternator regulator for my system then? They are $199 in Australia.

Ted

Sorry, Not Pete, MAINSAIL..

Rustic Charm · 04-06-2012, 06:28

Mainsail, In your article on 1Both2off, you have what looks like a fuse panel set up with what looks like five (5) ANL fuse holders.

What is a battery monitor shunt?

and what is

From Battery Switch Feed?

Also, what size ANL fuses do you have in these?

Ted

Maine Sail · 04-06-2012, 06:43

Quote:

Originally Posted by tedsherrin

Mainsail, In your article on 1Both2off, you have what looks like a fuse panel set up with what looks like five (5) ANL fuse holders.

What is a battery monitor shunt?

and what is

From Battery Switch Feed?

Also, what size ANL fuses do you have in these?

Ted

A shunt measures the current (actually measures mV drop) across the shunt for a battery monitor. The battery monitor uses this mV drop to calculate current flow and transpose that into state of charge etc..

Fuse sizes are based on the wires ampacity. What I use for fuses may not be what you would use if you have smaller wires or a differnt engine and you plan to start off a fused bank.

I sized the main battery fuses to handle starting loads for our engine. The alternator fuse is sized to protect the alternator wire, the inverter fuse to protect the inverter wire and the battery charger fuse to protect the battery charger. They are different sizes except the two main fuses from bank #1 & #2 which IIRC are 250A ANL's..

On that panel "from battery switch feed" connects to the "C" post on the battery switch. When the switch is energized by bank #1 or bank #2 that pos buss bar is also energized powering the DC loads & inverter it just neatens things up and gets multiple large lugs off the "C" post of the battery switch..

This is what it looked like in the boat..

Rustic Charm · 04-06-2012, 15:11

Thanks Mainsail,
So, its the wire I need to plan to protect when installing fuses?

So, if my chosen wire is rated at 175amp, do I put in a 175amp fuse or a bit smaller?

ted

Rustic Charm · 05-06-2012, 03:32

Quote:

Originally Posted by Maine Sail

On that panel "from battery switch feed" connects to the "C" post on the battery switch. When the switch is energized by bank #1 or bank #2 that pos buss bar is also energized powering the DC loads & inverter it just neatens things up and gets multiple large lugs off the "C" post of the battery switch..

I really like what you have done and thus I have ordered an ACR and four ANL holders to begin. BUT, I'm really not following what you have done. Sorry to be a pain.

Firstly, you have 'to switch 2', in one end and then 'from reserve bank' on the other. Which I presume is the battery reserved for the starter motor.

and then you have the Alt Feed from the ACR into an ANL, but that ANL looks like it's joined with the one to the house bank and switch 1? So where does it go to the Alt?

I don't suppose you have a scematic that incorporates this above and also the best wiring for the 1/both/2/off switch you recommended?

tED

Rustic Charm · 05-06-2012, 04:45

Actually, I've drawn up a repeat of your fuse panel and incorporated the switch. So I have two questions.

Firstly, where does the Alt go?
Secondly, where does the no 2 position on the battery switch go?

Ted
Colour drawing attached.