Rewiring with Upgrades

[Terra Nova]

Originally Posted by Frankly

...My personal preference is battery(s) directly to switch and then fuse the switch output (common) PDQ...

I prefer to not look for loopholes in ABYC's general recommendation. Nor would I choose to begin with a compromise unless there were some extenuating circumstance. Somehow every installation has provided a means to stick pretty close to their specs. But I must admit to regularly exceeding the 7" limit, by paying strict attention to routing.

[smac999]

considering battery's are over 7" tall it's pretty hard to meet that rule... unless you have a wall handy. most cases busses and anl fuses are on the ground. MRBFs are great on some boats but not all. cover the wire and you get 50+" (forget exact number, don't use a measuring tape when wiring...) there is a 70" rule in there somewhere too.

[Bill_E]

Fuses, etc. I suppose one should read all of the manuals completely before doing anything!! Well, this was an installation by the PO and I'm improving and upgrading so maybe I've got an excuse.

The Freedom 30 manual does not specify cable size but it does specify a 300 A fuse and that is what is in the original installation. In several years I haven't had any incidental fuse blowing so I guess I'm OK with the general setup. The manual also says that the charger is limited to 140 amps at 12 volts. I'm thinking of leaving the switch (Blue Sea 9003E) followed immediately with the 300 A fuse and then about 3 1/2 to 4 ft of 2/0 cable to the house bank. I'm hoping to be able to lay the cable more efficiently and perhaps shorten it by a little.

I have an MRBF on my house bank now and am tempted to continue with that as the fusing option for the battery output.

Regarding batteries: I am beginning to see the advantages of good golf cart batteries. I'm wondering if two of them will be sufficient. When considering batteries, what are the most important parameters? Amp hours? My Optimas are only 55 Ah each and there are lots of golf cart batteries at 150 and more Ah. Or is the Reserve Capacity a more useful parameter? Again, there are lots of golf cart batteries with high reserve capacities. I'm going to have to do a whole lot more reading on this issue.

Bill

[fallingeggs]

Originally Posted by Bill_E

Fuses, etc. I suppose one should read all of the manuals completely before doing anything!! Well, this was an installation by the PO and I'm improving and upgrading so maybe I've got an excuse.

The Freedom 30 manual does not specify cable size but it does specify a 300 A fuse and that is what is in the original installation. In several years I haven't had any incidental fuse blowing so I guess I'm OK with the general setup. The manual also says that the charger is limited to 140 amps at 12 volts. I'm thinking of leaving the switch (Blue Sea 9003E) followed immediately with the 300 A fuse and then about 3 1/2 to 4 ft of 2/0 cable to the house bank. I'm hoping to be able to lay the cable more efficiently and perhaps shorten it by a little.

I have an MRBF on my house bank now and am tempted to continue with that as the fusing option for the battery output.

Regarding batteries: I am beginning to see the advantages of good golf cart batteries. I'm wondering if two of them will be sufficient. When considering batteries, what are the most important parameters? Amp hours? My Optimas are only 55 Ah each and there are lots of golf cart batteries at 150 and more Ah. Or is the Reserve Capacity a more useful parameter? Again, there are lots of golf cart batteries with high reserve capacities. I'm going to have to do a whole lot more reading on this issue.

Bill

For what it is worth, "golf cart" batteries seem to be used as a generic term for 6 volt batteries. Most claim to be "deep cycle" batteries, but there is a wide degree of quality when it comes to true deep cycle batteries. Unless you really want to learn about batteries, I'd stick to quality brands to make thing easier. (That's what I'm doing!)

The most common measurement used by folks is the amp hours at a 20 hour test. (Maybe not the most technical language there, but it should be clear when looking at the specs.) Trojan also lists out various other amp hours at different ratings, such as 5, 10 and 100 hours.

Check out Trojan's website under their 6 volt marine batteries. You will see a wide selection all the way up to their big boy L16Hs at 435 amp hours or their most common size of 105s at 225 amp hours. Find the biggest you can fit and call it a day. More difficult things to tackle.


Sent from my iPhone using Cruisers Sailing Forum

[Maine Sail]

Originally Posted by Bill_E

Regarding batteries: I am beginning to see the advantages of good golf cart batteries. I'm wondering if two of them will be sufficient. When considering batteries, what are the most important parameters? Amp hours? My Optimas are only 55 Ah each and there are lots of golf cart batteries at 150 and more Ah. Or is the Reserve Capacity a more useful parameter? Again, there are lots of golf cart batteries with high reserve capacities. I'm going to have to do a whole lot more reading on this issue.

Bill

Bill,

It's not just Ah's or reserve capacity it is a combination of cycle life, Ah's and cost.

Keep in mind that Group 24, 27 & 31 batteries are not really a true deep cycle battery, in flooded designs. When compared to their sister cases, in starting or dual purpose types, they appear to be "deep cycle" but when compared to an actual deep cycle battery, such as a GC2 6V or a GEL or a premium quality AGM battery, they are not really deep cycle.

Trojan for example rates their entire 12V SCS "deep cycle" line up at just half the rated cycles of their GC2 6V / T105. Half the rated cycles! How many know this when buying the Trojan 12V SCS "deep cycles" batteries? Probably less than .5%, if I had to guess.....

What's the better value, 200Ah's of Trojan 12V batteries or 200 Ah's or Trojan 6V batteries when the 6V batteries will deliver double the cycles of the 12V, in the lab...?

What's the better value a Deka GEL battery rated at 1000 cycles vs. a Deka AGM rated at 300 cycles? Even if the GEL cost $50.00 more this is a steal, if you charge them correctly.

Most Group 24, 27, 31, 4D & 8D 12V flooded batteries are all what I call "imposter deep cycles" including the Trojan SCS series 12V G-24, G-27 & G-31... Some flooded 12V deep cycles will give more cycles than others, in these group sizes, but none compete directly with a true deep cycle battery such as a GC2 6V in terms of cycle life..

Battery buyers should always try to understand they are are not just buying Ah capacity they are buying expected cycle life too. The trouble is it is nearly impossible to compare cycle life claims, between manufacturers, because most don't rely on independent labs that test to a standard. Within a brand the cycle life data is useful guidance but brand to brand is not...

There are 12V deep cycle golf cart batteries such as the Trojan T1275, and they do have the same cycle life as a 6V T105, but they are also taller, like the GC2 6V, and a built to use the same plates as a GC2 battery. They are also pretty darn pricey compared to T 105's due to lower volume. This is why most just use the GC2 6V case in a series or a series parallel configuration for 12V...

G-24, 27 & 31 flooded batteries simply do not have the plate thickness a GC2 6V battery does because they are adapted battery case sizes from the 1950's automotive world......

For example in the Deka / Sea Volt / West Marine line you have starting, dual purpose and deep cycle G-24, 27 & 31 12V batteries which all share the same case. However they are only really deep cycle when compared to the starting or dual purpose batteries with which they share the identical case. They are not "deep cycle" when compared to the GC2 6V or other actual deep cycle batteries. Deep cycle? Compared to what? This is what needs to be asked....

Here's the data across the Deka / East Penn / West Marine line up:

Flooded Batteries - Group 24, 27, 31 4D, 8D & 6V GC2

12V Starting - Cycles to 50% = Not Rated
12V Dual Purpose - Cycles to 50% = 200 (4D & 8D)
12V Deep Cycle - Cycles to 50% = 350 (G24, 27, 31)
6V Golf Cart - Cycles to 50% = 700-1000 (GC2, L16 etc.)
AGM - Cycles to 50% = 300 (all case sizes)
GEL - Cycles to 50% = 1000 (all case sizes)


*Note: The above are LAB RATED cycles. Expect less in the real world..

As can easily be seen the 12V "deep cycle" battery is only a "deep cycle" when compared to the starting or dual purpose batteries it shares a case with. If you absolutely must buy a 12V G-24, 27 or 31 buy the deep cycle version. In many cases this is all that will fit. It is easy to see that these are not really deep cycle when compared to a truer deep cycle battery.

The only ones that have lab rated cycles the same or close, to their own brands 6V batteries, are Lifeline AGM's. I know of no other brand that will rate their G-24, G-27 or G-31 at even half the cycles of their GC2 6V flooded batteries. The Deka / East Penn / WM product is less than half...

It should be noted that West Marine, for all the crap they take, is actually honest in their labeling of the Deka 4D and 8D flooded batteries and they don't lie and call them deep cycle like many other re-sellers of those identical Deka/East Penn batteries do.

Sadly the term "deep cycle" has been grossly bastardized, diluted and abused by the marketing teams. A Deka AGM at 300 cycles, or flooded 12V battery at 350 cycles is not what I would consider a deep cycle battery. A Deka GEL at 1000 cycles, or a GC2 6V are a deep cycle battery. I have one GEL bank that just entered its 15th season.. The 6V GC2 at 700-1000 cycles or L-16's etc. are also deep cycle batteries.

Remember its not just Ah capacity you are buying.. Cycle life is where the returns are... Still most batteries are murdered by their owners and lots get les than 20% of the lab rated cycles, in the real world... GC2 golf cart batteries almost always win when you look at $$ per Ah and $$ per cycle...

If you want the ultimate in deep cycling lead acid there are always 2V batteries such as those by Rolls.....

The GC2 6V market is extremely competitive and most brands, even the JCI (Johnson Controls) built 6V's, are pretty darn robust..

[Frankly]

If you decide to give the custom fuse block a go, here is a source of plated copper buss bar.

Copper Bar Alloy C11000 Silver Flashed or Plated for Electrical Bus Bar Applications

Buy some extra and make that ground bar to suit.

I also use a hand Nicopress crimping tool (West Marine) for making my own battery cables.

This ain't rocket science.

[muttskie]

Originally Posted by Maine Sail

Bill,

It's not just Ah's or reserve capacity it is a combination of cycle life, Ah's and cost.

Keep in mind that Group 24, 27 & 31 batteries are not really a true deep cycle battery, in flooded designs. When compared to their sister cases, in starting or dual purpose types, they appear to be "deep cycle" but when compared to an actual deep cycle battery, such as a GC2 6V or a GEL or a premium quality AGM battery, they are not really deep cycle.

Trojan for example rates their entire 12V SCS "deep cycle" line up at just half the rated cycles of their GC2 6V / T105. Half the rated cycles! How many know this when buying the Trojan 12V SCS "deep cycles" batteries? Probably less than .5%, if I had to guess.....

What's the better value, 200Ah's of Trojan 12V batteries or 200 Ah's or Trojan 6V batteries when the 6V batteries will deliver double the cycles of the 12V, in the lab...?

What's the better value a Deka GEL battery rated at 1000 cycles vs. a Deka AGM rated at 300 cycles? Even if the GEL cost $50.00 more this is a steal, if you charge them correctly.

Most Group 24, 27, 31, 4D & 8D 12V flooded batteries are all what I call "imposter deep cycles" including the Trojan SCS series 12V G-24, G-27 & G-31... Some flooded 12V deep cycles will give more cycles than others, in these group sizes, but none compete directly with a true deep cycle battery such as a GC2 6V in terms of cycle life..

Battery buyers should always try to understand they are are not just buying Ah capacity they are buying expected cycle life too. The trouble is it is nearly impossible to compare cycle life claims, between manufacturers, because most don't rely on independent labs that test to a standard. Within a brand the cycle life data is useful guidance but brand to brand is not...

There are 12V deep cycle golf cart batteries such as the Trojan T1275, and they do have the same cycle life as a 6V T105, but they are also taller, like the GC2 6V, and a built to use the same plates as a GC2 battery. They are also pretty darn pricey compared to T 105's due to lower volume. This is why most just use the GC2 6V case in a series or a series parallel configuration for 12V...

G-24, 27 & 31 flooded batteries simply do not have the plate thickness a GC2 6V battery does because they are adapted battery case sizes from the 1950's automotive world......

For example in the Deka / Sea Volt / West Marine line you have starting, dual purpose and deep cycle G-24, 27 & 31 12V batteries which all share the same case. However they are only really deep cycle when compared to the starting or dual purpose batteries with which they share the identical case. They are not "deep cycle" when compared to the GC2 6V or other actual deep cycle batteries. Deep cycle? Compared to what? This is what needs to be asked....

Here's the data across the Deka / East Penn / West Marine line up:

Flooded Batteries - Group 24, 27, 31 4D, 8D & 6V GC2

12V Starting - Cycles to 50% = Not Rated
12V Dual Purpose - Cycles to 50% = 200 (4D & 8D)
12V Deep Cycle - Cycles to 50% = 350 (G24, 27, 31)
6V Golf Cart - Cycles to 50% = 700-1000 (GC2, L16 etc.)
AGM - Cycles to 50% = 300 (all case sizes)
GEL - Cycles to 50% = 1000 (all case sizes)


*Note: The above are LAB RATED cycles. Expect less in the real world..

As can easily be seen the 12V "deep cycle" battery is only a "deep cycle" when compared to the starting or dual purpose batteries it shares a case with. If you absolutely must buy a 12V G-24, 27 or 31 buy the deep cycle version. In many cases this is all that will fit. It is easy to see that these are not really deep cycle when compared to a truer deep cycle battery.

The only ones that have lab rated cycles the same or close, to their own brands 6V batteries, are Lifeline AGM's. I know of no other brand that will rate their G-24, G-27 or G-31 at even half the cycles of their GC2 6V flooded batteries. The Deka / East Penn / WM product is less than half...

It should be noted that West Marine, for all the crap they take, is actually honest in their labeling of the Deka 4D and 8D flooded batteries and they don't lie and call them deep cycle like many other re-sellers of those identical Deka/East Penn batteries do.

Sadly the term "deep cycle" has been grossly bastardized, diluted and abused by the marketing teams. A Deka AGM at 300 cycles, or flooded 12V battery at 350 cycles is not what I would consider a deep cycle battery. A Deka GEL at 1000 cycles, or a GC2 6V are a deep cycle battery. I have one GEL bank that just entered its 15th season.. The 6V GC2 at 700-1000 cycles or L-16's etc. are also deep cycle batteries.

Remember its not just Ah capacity you are buying.. Cycle life is where the returns are... Still most batteries are murdered by their owners and lots get les than 20% of the lab rated cycles, in the real world... GC2 golf cart batteries almost always win when you look at $$ per Ah and $$ per cycle...

If you want the ultimate in deep cycling lead acid there are always 2V batteries such as those by Rolls.....

The GC2 6V market is extremely competitive and most brands, even the JCI (Johnson Controls) built 6V's, are pretty darn robust..

Wow, great post! Thanks, RC

[Bill_E]

Agreed!!

Now I've got to figure out how to best manage things. My battery boxes will probably permit a total of four batteries at best. If I keep one for the starter battery that leaves three for the house. If I use 6v GC2s then I can only get two of them in there. So I've got to go for the highest capacity. I guess that's greatest Ah. Dollars count but lifetime can change how one thinks about the price at the checkout counter.

Now back to the circuitry for the rewiring!

Bill

[Terra Nova]

The battery box I built for TN holds (4) L16 batteries for the house bank, providing nearly 800 a/h. I found another spot to add a small (group 27 or 31) start battery. This seems an optimum system for a cruising sailboat of modest size.

[Bill_E]

I'm back on this problem...Well a whole set of problems in rewiring. I had to take six weeks off for family stuff.

I'll have to investigate the battery issues at more length. I'm sure grateful for MaineSail's post.

Now I'm worrying through the cabling for the starter motor. On MaineSail's webpages, he recommends a fuse in the starter cable. Battery Bank Fusing Photo Gallery by Compass Marine How To at pbase.com I can do that but my main question now is what size cable and what size fuse? I've tried to figure out the starter motor draw...it looks like about 225-250 Amps. For an 8 ft cable run that would imply a 3/0 cable. The existing cable looks to be about 2 AWG. It's the original from the 1991 boat construction (I think). I don't think I can get 3/0 cable to make the necessary bends. I guess I'll check to see if I can get 2/0 cable in place. There is a good location for an ANL fuse. I suppose a 200 A fuse would be about right??

Any comments or suggestions?

More questions later!!

Bill

[mitiempo]

250 or larger fuse. For starting circuits you are allowed 150% of wire capacity.

[Bill_E]

Next installment: Here is a tentative wiring diagram for the positive cables for the system as I see it now. I hope it’s readable. (I should probably relearn my drawing program to make nice neat computer wiring diagrams since I’ve traced so much wiring down.) I’d love feedback on it. A drawing for the negative (ground) cables will be done soon.




(I hope I managed the picture)

A few comments: I think I can go with 1 AWG for the starter but I’m leaning towards 1/0 for less resistance. According to MaineSail’s pages, I think a 200 amp fuse is OK. If I blow one I can always keep a 250 in the tool box, it’ll be in an area where it would be easy to replace.

There are three circuit breaker, power distribution panels.
Panel 1 is the original (Sunbeam) panel. It contains most of the cabin lights, running lights, shower drain pump, deck light, SSB and that’s about it. The cable feeding it from the proposed busbar would be a serious PITA to replace because it is routed through a bunch of channels behind bulkheads. I estimate it is about 8 ft long.
Panel 2 was put in later and now contains only a couple of cockpit lights, a voltage and amperage meter, and two refrigerators, both with Danfoss compressors.
Panel 3 is the main power distribution panel put in last, by the PO. It includes all of the navigation electronics including radar and autopilot, fresh water pump, VHF, assorted special lights (most are LED’s at this point.). It is presently wired with 4 AWG cable and I’d rather not replace that cable unless there is a real hazard of overload that I am not seeing. It is interesting that the installer put a 100 amp ANL fuse in the cable, but it’s about 5 ft from the battery bank.

It is also interesting that the main positive cables from the battery to the charger and to the 3 way battery switch are 2/0 but the ground cables are 1/0. I always thought that you had to consider the whole loop and cables should be the same size all the way around the loop. I know it’s a lot easier to bend the smaller diameter cable but…

Thanks for any criticism or comments.

[muttskie]

Originally Posted by Bill_E

Next installment: Here is a tentative wiring diagram for the positive cables for the system as I see it now. I hope it’s readable. (I should probably relearn my drawing program to make nice neat computer wiring diagrams since I’ve traced so much wiring down.) I’d love feedback on it. A drawing for the negative (ground) cables will be done soon.




(I hope I managed the picture)



A few comments: I think I can go with 1 AWG for the starter but I’m leaning towards 1/0 for less resistance. According to MaineSail’s pages, I think a 200 amp fuse is OK. If I blow one I can always keep a 250 in the tool box, it’ll be in an area where it would be easy to replace.

There are three circuit breaker, power distribution panels.
Panel 1 is the original (Sunbeam) panel. It contains most of the cabin lights, running lights, shower drain pump, deck light, SSB and that’s about it. The cable feeding it from the proposed busbar would be a serious PITA to replace because it is routed through a bunch of channels behind bulkheads. I estimate it is about 8 ft long.
Panel 2 was put in later and now contains only a couple of cockpit lights, a voltage and amperage meter, and two refrigerators, both with Danfoss compressors.
Panel 3 is the main power distribution panel put in last, by the PO. It includes all of the navigation electronics including radar and autopilot, fresh water pump, VHF, assorted special lights (most are LED’s at this point.). It is presently wired with 4 AWG cable and I’d rather not replace that cable unless there is a real hazard of overload that I am not seeing. It is interesting that the installer put a 100 amp ANL fuse in the cable, but it’s about 5 ft from the battery bank.

It is also interesting that the main positive cables from the battery to the charger and to the 3 way battery switch are 2/0 but the ground cables are 1/0. I always thought that you had to consider the whole loop and cables should be the same size all the way around the loop. I know it’s a lot easier to bend the smaller diameter cable but…

Thanks for any criticism or comments.

I suggest you consider that the primary (house) bank positive goes to the positive buss. The positive bus would have the solar, charger, alternator output and any other un-switched positives (bilge pump, etc.) connected.The distribution panels and starter are fed by the C post of the battery switch. If the Duo-Charge is installed properly, the start battery will be kept charged. The start battery will go to one battery switch position and the house bank to the other position. Just a thought.

[Terra Nova]

I would:

place the 300-amp fuse right at the house battery; from that fuse I would go to everything else

place the 200-amp fuse at the start battery, with everything coming off it (except perhaps the starter)

place an on-off switch in starter, inverter and bus bar circuits

add a fuse at the alternator and run it directly to the battery fuse

add fuses to panels 1 & 2; locate all panel fuses near bus

locate the 50-amp fuse near the charge controller