1/BOTH/2/OFF Switches Thoughts & Musings

[mitiempo]

All battery banks should have a main switch. ABYC and common sense are the reasons.

As far as durability of the switches I have seen very few bad ones, mostly decades old. I have never seen a Blue Seas battery switch fail in normal use - or any other good brand for that matter.

Heavy loads like a watermaker? Spectra's largest 12 volt watermaker draws 26 amps @12 volts.

 

[Maine Sail]

Why have a 1-2 switch at all? In fact Ample Power says that all battery 1-2-both switches are prone to failure because of the high loads put on them by water makers and the like. The only switch that they recommend is a emergency bypass switch should the dedicated starter battery fail.

Please take Ample Powers stuff with a grain of salt as there is some questionable advice in there.. Since reading that many years ago I have been looking everywhere for these so called melted switches that are going to happen. Perhaps thousands of switches and not yet found a melted one.. Just yesterday alone I saw the backs of 6 battery switches.

Battery switches are required under ABYC standards if the cranking amp capacity greater than 800 or the Ah capacity is 100Ah or greater. Cranking amps is the default. This 800 CA exemption however was intended to allow for small boats such as skiffs and open boats to avoid a switch in a corrosive environment. Surveyors follow ABYC and a boat, with a cabin, without a battery switch will very likely get flagged. If you need to pass an insurance survey you will need a battery switch. Beyond that they are just a wise investment.

What happens when you smell smoke, as happened to myself and another member here on this forum during a race? You dive for the battery switch and cut it immediately. No battery switch............?What happens when you have a battery that develops a catastrophic internal fault? Do you get in there and physically un-wire it risking battery acid in the face if it goes thermal? With a battery switch you simply isolate the bank/battery.

I work on boats for a living, as a marine electrician, and have never once seen a physically melted US type battery switch, (European Beneteau/Jenneau, Hanse type switches I do see melted and failed) that was properly rated for the use. Even then I see piles and piles of switches that were undersized for the use (usually on power boats) and they still survive..

This one came off a commercial lobsterboat. It started a very large 3208 Caterpillar diesel and ran massive pumps, and equipment, for nearly 25 years. It was only removed during a re-wire and the proper HD switch was installed. I though for sure this one would be my golden ticket to Ample's "melted switch phenomenon" but it was not. Despite this boat ideally needing a "heavy duty" battery switch this standard grade switch was in fine health even after 25 years......

I have opened up a number of switches to autopsy them and found even 35 year old switches in fine health. For sailboats finding a melted one has proven to be the proverbial needle in the haystack..

The loads imposed by sailboats barely even constitutes a load to a battery switch. I work on boats with 1600HP+ engines that start with Guest, Perko or Blue Sea battery switches. I have bow thrusters that pull 300A continuous (600A in-rush) that run through battery switches and again not a single failure/melt down. A water maker does not even begin to constitute a load to a battery switch....

Even Blue Seas smallest battery switches, the "mini" series (m-Series) can handle 300A continuously, 500A for 5 minutes, 775A for 1 minute and 1500A for 10 seconds. There is NOTHING on our sailboats that can exceed these load ratings and this is the absolute smallest battery switch Blue Sea makes...

The Blue Sea e-Series is: 350A continuously, 600A for 5 minutes, 1000A for 1 minute and 2000A for 10 seconds

The Blue Sea HD Series is: 600A continuously, 700A for 5 minutes, 1150A for 1 minute and 2750A for 10 seconds.

Keep in mind that there is not even battery cable big enough to handle the ampacity that a Blue Sea HD switch can, and they are reasonably priced....

Even 4/0 105C battery cable can only handle a max ampacity of 445A outside an engine space and 378A inside an engine space. A Blue Sea HD switch can handle 600A without issue. Even the mini series continuous rating exceeds the max ampacity of 1/0 105C wire and the standard series continuous exceeds 2/0 105C wire.....

Again, some of what Ample has written has not held true in the real world. Take for instance their article on breaking in lead acid batteries. Trojan Battery vehemently disagrees with his suggested process yet it is posted as fact by Ample power.... I think I will trust the actual battery manufacturer on how best to break in service batteries....

 

[Brad Hoff]

Great discussion here. I rewired my system so that I had a dedicated start battery and use a Balmar Duo charge unit. I changed the switch to 1, 1&2, off. I understand that this is not the best wiring for starting with a dead house ban (#1) as the only choice is combining both. My issue was that every time I started the engine, my electronics would cycle off. In the PNW, sometimes I have to start the engine many times a day due to fluky winds. It was a PIA having to either turn off my GPS, radar, etc every time I started the engine. Don't have that problem now. I do not see any other simple wiring system for my situation. Does anyone else have this problem with the large voltage drop and equipment shutdown when starting on the house bank?

 

[Brad Hoff]

I just saw your post #50 and that wiring setup would be better than the (1, 1&2, off) that I now have. I am isolated in start and house but can only combine for the start. I cannot use only the house for starting. So far my setup has been ok but I can see there may be a time that I would want just the house for starting, not a combination of both.

 

[Brian D]

Sorry to bring up an old issue, but on the image in post 50, where does one place the battery charger/solar panel controller/alternator?

 

[Maine Sail]

Sorry to bring up an old issue, but on the image in post 50, where does one place the battery charger/solar panel controller/alternator?

House bank + post or #1.....

 

[Brian D]

Thanks, Maine!

 

[SailingHarry]

This is a long running post, but it's great to get all this info in one place. I currently use the 1-2-b switch as described by Maine, with a house bank of 2 golf carts and a very small FLA "reserve" (I think it's like a 27, but not sure). Since installing the system, I've never used the 2 position. I also have a 100A alternator and a TrueCharge 40.

My problem is that, to date, I can only charge the battery by using the "B" or my 2-output shore power charger. Since I am usually plugged in, and only cruise for weekends (or maybe a week), I don't worry much about the spare -- it's charged at home and it "just there" underway.

I'd like to add a combiner to complete the ideal system. But which one? The ones I've seen are:
Blue Seas Mini ACR $52, only 65A rating, no remote LED
Yandina $56 (looks stupidly plain -- but rock solid!)
Victron Cyrix $58
BEP DVSR $72
Charles BattCom $77 (250A!!)
Blue Seas SI-ACR $86
Cole Hersee Smart $86
Sterling ProLatch $150 (only 80A, but near zero power consumption)

Lots of options in the $50-90 range. Is there any reason not to go with the very cheapest, the Blue Seas Mini at $52? For another $4, the Yandina allows a remote LED indicator and their customer service is legendary. The Sterling power draw is nice, but doesn't seem to add $50 in value for my application.

Thoughts?

 

[mitiempo]

I would use an Echo Charge. Simple to install, large cabling not needed as it is with an ACR/combiner. As it is 15 amp output ANL fuses are not required either, which can increase the price of an ACR substantially.

 

[SailingHarry]

I would use an Echo Charge. Simple to install, large cabling not needed as it is with an ACR/combiner. As it is 15 amp output ANL fuses are not required either, which can increase the price of an ACR substantially.

EchoCharge is a Xantrex product. Good luck contacting customer service! I had a ProSine 2KW that is dead (I got it that way for waaaay cheap, with high hopes). Xantrex NEVER returned several contact forms I filled out on their service web site (never could find a phone number!), and I have since learned that the unit is considered "non-serviceable." If their standard policy on a piece of equipment that expensive is "go buy a new one" then, I have no interest in buying anything from them. I tossed the ProSine.

Harry

 

[mitiempo]

The Echo Charge was not designed by Xantrex and they have not changed it since the company that designed it was purchased. I have installed many (and own one myself) with zero problems. As has MaineSail.

 

[SailingHarry]

I would use an Echo Charge. Simple to install, large cabling not needed as it is with an ACR/combiner. As it is 15 amp output ANL fuses are not required either, which can increase the price of an ACR substantially.

So even though I don't like Xantrax, I went and took a look anyway. Seems some folks have had fairly good luck with the EchoCharge, even Mainsail reports it's an OK product. I'm a bit confused. It's almost double the price of an ACR, but I don't see the value.

It is NOT a "smart charger" that uses the house battery as the power source, and then charges the second battery according to some regime. It is more like a high resistance voltage limiting ACR. It turns ON at 13V like an ACR, but when on it has an interesting current/delta-V curve, where it won't allow much current to flow when there is a low voltage difference (although current won't flow much then anyway). It also won't allow much current to flow when there is a HIGH voltage difference (a very low reserve battery, and a fully charged house battery -- a bad situation to be in for sure!). It does have an output voltage limit of 14.4, but my shore charger only puts out 14.4 during Bulk/Absorption (except at very cold temperatures), so the EchoCharge won't ever limit the charge. I use a "dumb" internal regulator, that only puts out 14.4, and even a Balmar regulator only puts out 14.6 during Bulk and 14.4 for Absorption (the Balmar would do that on startup even if you had spent a week on shore power, so the house battery will see that 14.6 -- if that is bad for the reserve, it's bad for the house too!).

So, what am I missing? What does an EchoCharge give that an ACR doesn't?

 

[mitiempo]

If you are installing an ACR you will need 2 ANL fuse holders and 2 ANL fuses. You will also need to use heavy cabling. Added up it will double the ACR price, or more.

An Echo is limited to 15 amps and because of this fusing is simple and less expensive. You can use the fuses that come with the Echo or even if you replace them with better fuses you are only looking at a few dollars more.

 

[SailingHarry]

If you are installing an ACR you will need 2 ANL fuse holders and 2 ANL fuses. You will also need to use heavy cabling. Added up it will double the ACR price, or more.

An Echo is limited to 15 amps and because of this fusing is simple and less expensive. You can use the fuses that come with the Echo or even if you replace them with better fuses you are only looking at a few dollars more.

I have 200A ANL fuses on both batteries. If I go with the Charles BattCom, I'm set with no additional fuses (but I'll need #2 wires -- huge for the job!). If I go with something smaller, I have "some" risk, but limited. I would need a high current fault that lasts long enough to fry the wires, but not high enough to blow the 200A fuses.

Or, I can connect it on the protected side of 2 100A breakers I have on each battery after the 200A fuses. These provide power to some "always on" loads like battery chargers, bilge pumps, etc. That way I only need #6 wires.

Come to think of it, you'd need to do that with the EchoCharge as well (either downstream of protection, or very large wires).
Harry

 

[mitiempo]

I have 200A ANL fuses on both batteries. If I go with the Charles BattCom, I'm set with no additional fuses (but I'll need #2 wires -- huge for the job!). If I go with something smaller, I have "some" risk, but limited. I would need a high current fault that lasts long enough to fry the wires, but not high enough to blow the 200A fuses.

Harry

True. Large cables are always required when paralleling batteries. Some prefer not to, hence the Echo.

 

[Maine Sail]

Harry,

The Blue Sea 120SI is one of if not my favorite combiner for an application like yours. The Yandina's are well backed but I use mostly the 120SI on an install like yours. I have broken a couple cases on the Yandina's, and they always send another without issue, but it takes time to tear them down to replace the case.

The Blue Sea ACR's are extremely well built and over engineered and don't mandate what size and length wires you must use, Yandina does. With the 120SI if you use jumpers capable of the batt fuse ratings then no need to buy extra fuses. I have never seen or heard of 120SI fail except for lightning damage. IMHO, and from many direct conversations with Blue Sea's head of engineering, I know their stuff is put through the testing ringer like no other company in the marine market place.

I know nothing about the Charles and like many of their products I suspect it was out sourced as a filler product to their IT's and battery chargers? Could be in-house but I feel like I have seen it somewhere before..

Blue Sea has designed their product in-house, built it specifically for the marine environment and thoroughly tested it. It is completely sealed. They also stand behind their products at the top level in the industry. I am not a fan of the Cyrix or the BEP product when compared to the BS ACR...

That said the Echo charger is literally bullet proof and very easy to install but don't expect much in the way of support. I only know of one failed Echo Charger and it appeared to have been dropped. You always have the BOTH position if you need more current.

For your situation you really don't "need" any of these devices but they do make it seamless, remove a lot of HEF and are an extremely reliable class of product..

Please keep in mind that you are fusing for the protection of the wire not the device. The wire should be sized to carry the alt load but can certainly be bigger, if you want to minimize the number of fuses and use your 200's.. I would not suggest using 100A fuses with a 100A alt as you don't want to be running any fuse at more than 80% long term and with a 100A alt this is cutting it close..

Also remember that all OCP is additive to voltage drop. The larger the fuse in relation to average current the less voltage drop you will see. In charging systems minimizing voltage drop is critical...

 

[SailingHarry]

Harry,

The Blue Sea 120SI is one of if not my favorite combiner for an application like yours. The Yandina's are well backed but I use mostly the 120SI on an install like yours. I have broken a couple cases on the Yandina's, and they always send another without issue, but it takes time to tear them down to replace the case.

Maine,

Thanks so much for the reply. You would pick a pricey one -- but isn't that always the case? That 120SI is a nice looking unit, no doubt.

I agree, I don't really "need" it, as my system has been working just fine. The way I cruise, I don't need ANY charging for my "reserve" when underway. But since I'm cleaning up a bunch of wires near the battery, I figured I'd do this part too. But maybe I'll just mark a spot on the bulkhead for "ACR, future" and not do it right now.

One question about the Mini_ACR. It's only rated at 65A, and my alternator is "rated" at 100, but as you know it only puts out what is needed (and even then, it can't ever put out the full 100!). The alternator is going to the house, and the ACR to the reserve (a single group 27 FLA, I think). The reality is that it will be almost impossible to ever put even 20A through the ACR. Is the Mini a reasonable option, or just pay the extra $30 and never think about it again?

Thanks again,

Harry

 

[Maine Sail]

Maine,

Thanks so much for the reply. You would pick a pricey one -- but isn't that always the case? That 120SI is a nice looking unit, no doubt.

I agree, I don't really "need" it, as my system has been working just fine. The way I cruise, I don't need ANY charging for my "reserve" when underway. But since I'm cleaning up a bunch of wires near the battery, I figured I'd do this part too. But maybe I'll just mark a spot on the bulkhead for "ACR, future" and not do it right now.

One question about the Mini_ACR. It's only rated at 65A, and my alternator is "rated" at 100, but as you know it only puts out what is needed (and even then, it can't ever put out the full 100!). The alternator is going to the house, and the ACR to the reserve (a single group 27 FLA, I think). The reality is that it will be almost impossible to ever put even 20A through the ACR. Is the Mini a reasonable option, or just pay the extra $30 and never think about it again?

Thanks again,

Harry

The 5 minute rating on the ACR Mini is higher than 65A and 65A is the continuous rating. Personally I would not do that, especially for the $18.00 difference, but you'd probably be fine. If you ever depleted that other battery using BOTH would be better than pushing all that current through the ACR.. The 120SI also has SUBSTANTIAL lugs and ample room to wire it.

For example with a thick COPPER washer between the MRBF and the main batt cable lug I can add an ACR to a battery compartment that lacks the height for a MRBF fuse and mount the fuse to the ACR 120SI stud. There are very few combiners that you can do this with. Most have dinky little studs and barely room for the parallel wiring. The 120SI makes it easy. The S-34 MKI is one of those boats that lacks height for an MRBF but that does have room for an ACR...

A short 7" jumper to the house POS from the MRBF and the install is done. The other bank also gets a fuse...

 

[wufibugs]

Maine, I am going to reconstitute my switch as per your diagram with the separate on/off switch. However I still using my battery isolator until I can change it out for a combiner. At present, the alternator output is to the isolator. Your suggestion is that it be rewired to the house bank. Can you post or send me the attached diagram showing how it would be wired for the isolator.

 

[SailingHarry]

Maine, I am going to reconstitute my switch as per your diagram with the separate on/off switch. However I still using my battery isolator until I can change it out for a combiner. At present, the alternator output is to the isolator. Your suggestion is that it be rewired to the house bank. Can you post or send me the attached diagram showing how it would be wired for the isolator.

An isolator inserts a voltage drop, which is the issue you need to address. If you have an alternator with a remote sense, it is really not much of an issue. If you sense on the house bank, and you have the combiner set "normally," then both batteries will be largely charged the same. If you have an internal regulator, you can either install the regulator the "normal" way, and simply see a reduced charge regimen, or you could install it in an "alternate" way.

An "alternate" way would be to only use one half of the isolator. If you send the alternator to the house bank direct, the house bank will get full force charging. The alternator will see the house bank voltage and regulate accordingly. Since the house bank is the main bank that you use routinely and heavily, this is good. Then, take the isolator and install it with only ONE HALF between the house and the reserve. Install it with the house going to the "input" or center terminal, and the reserve on one (or both, for slightly better performance) of the output terminals. When the house bank is being charged, the reserve will see some charge effect, but not much (although it will see charge voltages higher than "float" and will certainly keep it topped up -- it should see charging voltages around 13.5). This is probably OK, since the reserve needs very little charging. The downside is that a discharged reserve battery (internal short, some hidden load, etc) will discharge the house battery as well (since you are only using one diode, you only have protection in one direction, not both directions).

No really good options, just different compromises. But that is life in general, isn't it?