Charge relay help

[mrlee]

Hi everybody. Well, I fixed the leak and changed all the seacocks...whew. Now on to a new issue for me. I am changing the battery selector switch to the Blue Sea 5511e Dual Circuit Plus Battery Switch. If I have 450 Watts of solar and a Xantrex 40A controller (450Ah of battery) do I still need the battery combiner/relay from Blue Sea as well? Or, are these 2 separate circuits? Can anyone send me a link to a diagram for all of this? I have searched the web and I found nothing with this combination. Even Morningside and Xantrex could not give me any help. Thanks in advance...I continue reading all these forums and have learned soooo much from you all. Thanks

[exMaggieDrum]

Blue Sea has some circuit diagrams on their website and in their catalog, but, you have to have a basic understanding of battery circuits and battery management. They do a lousy job of describing their switches though. I have been looking at them myself the last few weeks and I have had to go to multiple sources to figure out how some of their switches really work.

The Dual Plus 5511e switch is primarily designed to simultaneously switch two separate battery banks to two separate loads, and to combine/parallel the batteries/loads if required. It has two inputs for two battery banks and two separate load outputs. So you can turn on the start battery-starter circuit and the house battery-house circuit with one turn on the switch. Or you can combine all loads and batteries together at a different switch selection. You have Off-On-Combine as your options. So you cannot keep the start circuit off when you have the house circuit on and vice versa.

There are times you might want to combine your batteries if one is dead and you need juice to power the other circuit. E.g. if the start battery is dead and you need to start the engine with the house battery, or, the house battery is dead and you need to use the VHF radio or power lights or whatever (in an emergency situation).

If you want to charge both the house and start batteries at the same time from whatever charge source(s) you have when you set the 5511e to "combine". I don't like doing this myself as you will be charging what are normally two different types of batteries with the same charge regimen. For the same reason, I don't like combining relays, which are a separate device to automatically combine two battery banks when one (normally the house) is being charge over a given set voltage. I prefer to use the Xantrex Echo Charge (or similar) to give a "trickle" charge to the start battery when the house battery is being charged. The start battery normally does not need a heavy charge. But if you need to, you could combine or parallel the banks during charging if your switches are set up to do that - like with the 5511e.

Your controller is designed to manage the type of charge you get from your solar panels so that the battery charging is maximized with no damage to your batteries. Interestingly, I can't find any charge controllers on the Xantrex website - at all - any flavor. But I did find some docs on it on some wind/solar power vendors. It looks like it can charge only one battery bank. You would use it for converting your solar power so the batteries can be charged effectively and efficiently. It is not the best type as it is uses Pulse Width Modulation (PWM) instead of MPPT. There are multiple discussions here on that issue. It will work though. So it would be connected between your solar panels and your batteries (one bank).

It is not a relay or a combiner and does nothing to charge more than one set of batteries. So you would need a separate switch and/or relay to combine batteries with or without the charge controller.

There are more varieties of switches than there used to be. I personally like having three switches - one start, one house, and one to parallel both but that is a bit much for a smaller boat. And any particular combo type switch can be wired in different ways to accomplish specific things.

But, a very usual configuration for a boat with a start battery, house battery(s), one engine starter, and separate house loads could use the 5511e. One battery is on "1", one on "2", starter on output "1" and house panel/circuits on output "2". Your solar charge controller would be wired to the house batteries. Your alternator ditto. If your house battery is similar to the start battery (wet flooded both) then you could combine them when charging - i.e. with the engine alternator or the solar panels. When they aren't combined the house battery would be charged but not the start battery. You could add the Echo Charge (or similar) to charge the start battery any time the house battery is being charged, regardless of whether the banks are combined or not. Or you could add a separate battery combiner/relay (but for the same money I would go with the Echo Charge).

If you need more info you need to give more info on what you have and want to do. Good luck and welcome to the complexities of battery circuits.

[Stu Jackson]

Originally Posted by mrlee

Blue Sea 5511e Dual Circuit Plus Battery Switch

Not a good idea for a sailboat with an aux engine.

It separates the banks, sure, but if one goes belly up you are forced to combine them.

The only time two banks should be combined is when charging, NOT when you have an "issue."

Here's more:

AGM Battery Issues and the Blue Seas Dual Circuit Switch (from Maine Sail) "DARN AGM Batteries"
Darn AGM Batteries - SailboatOwners.com

And exmd is right, a simple 1-2-B switch with the alternator output going to the house bank is much better and simpler.

Here's more on auto combining banks:

What are ACRs, Combiners & Echo Chargers? (by Maine Sail)
http://forums.catalina.sailboatowner...d.php?p=742417


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These links come from here:

http://c34.org/bbs/index.php/topic,5977.0.html

[mrlee]

Thanks for the clarification on this...Lots of great info here for me to ponder over. I like the Blue Sea as the battery banks are separated, I just went through an ordeal with a leak and it was hell when the batteries went dead over night with the bilge pump running so much. I want to be able to start her anyway so I can charge the house bank if there is another issue...I guess I'm gun shy now...
So with this switch and the Echo combiner I can set up the solar as normal and all is fine? Thanks a lot guys...Now to go read all this new info...

[smac999]

the blue sea system is great. yes you want the ACR. though mostly for engine charging to both banks. it's not really needed for solar as solar would only be going to the house bank anyways. unless you don't start the engine for months the engine battery shouldn't need solar maintaining.

[smac999]

Originally Posted by Stu Jackson

And exmd is right, a simple 1-2-B switch with the alternator output going to the house bank is much better and simpler.

except you are voltage spiking the crap out of your electronics every time you start the engine. and constantly switching back and forth every time you start or stop the engine. the loads should be separated onto the 2 banks. not sharing. 1-2-all switches are a thing of the past. if you want to be able to disconnect one bank in case there is a problem then 3 on / off switches would be better. like the BEP system. but one switch is way nicer. and in the rare event of a damaged battery it takes 20 secs with a wrench to disconnect the bad bank. then switch to both, and power everything off one battery.

[mrlee]

That's what I was thinking...Thank you for that. I can even put a single separate switch on the engine side so it won't be on all the time, correct?
I appreciate the reply. Have a great day.

[Maine Sail]

Originally Posted by smac999

except you are voltage spiking the crap out of your electronics every time you start the engine. and constantly switching back and forth every time you start or stop the engine. the loads should be separated onto the 2 banks. not sharing. 1-2-all switches are a thing of the past. if you want to be able to disconnect one bank in case there is a problem then 3 on / off switches would be better. like the BEP system. but one switch is way nicer. and in the rare event of a damaged battery it takes 20 secs with a wrench to disconnect the bad bank. then switch to both, and power everything off one battery.

In a properly wired system I have not seen this to be an issue and I have physically looked for it and had an o-scope on numerous boats trying to pin this down.. I don't at all disagree that it can happen but I've not been able to catch it even with some very sophisticated equipment. The batteries seem to work quite well as filters, if the system is well wired....

Sadly most of these arguments only ever revolve around "engine starting" but the starter is far from the only device on a boat that can, in-theory, throw a fault into the system and most of these systems are wired directly to the house bank..

Windlass Solenoid
Electric Winches
Engine Driven Refrigeration Clutch
Bow Thrusters
Water Makers
Any DC motor
Alternators
Wind Generators
Inverters

etc. etc...

There are many causes of electrical issues on boats that can, in-theory, cause issues yet the gear is still incredibly reliable. I would estimate that about 70% ofmy sailboat customers use the house bank for everything. In a recent battery use survey on SBO.com we had over 1000 responses from sailors and 66% said they used the house bank for everything.


Other potential issues usually ignored:

Voltage Transients
Electro-Magnetic Interference (EMI)
Low Voltage
Ripple (poor quality chargers etc.)
Voltage Sag Under High Loads
Voltage Surges
Lightning induced EMF
Human Error (switching off a battery switch with motor running etc.)

While I agree I prefer a properly wired, three ON/OFF switch configuration, it's not always worth the cost for an owner who can't DIY when his / her 1/2/BOTH has been working just fine for, well, oh perhaps 30+ years...

In late July I was called to a 1978 Grand Banks for a "windlass issue". This boat has been starting and running house loads off the house bank for perhaps 37 years. The current owner has had her for 22 years and only every uses switch position #1, for everything. The other battery bank, a 4D, sits there and looks pretty just in case the owner kills the house bank.


3283 Hours is a LOT of starts..


The feared and vilified 1/2/BOTH


Every piece of electronics on this vessel went out of "current" technology many, many moons ago. I estimate the VHF radio at 1981-1984 vintage and even the RayNav 580 Loran C still power ups (but no Loran signal of course).. This Furuno radar and Garmin 210 are both 15-20 + years old....


The owner stepped on this windlass switch, into a stalled motor, so many times and for so long that the breaker finally tripped... All this while the radar and GPS, motor and all other electronics were on and running & being powered off the same bank..


Yes I have tried to talk the owner into a dedicated starting circuit for the big Ford Lehman but the owner looked at me and said;

"RC, look at the age of this equipment, if there was such an issue caused by how I have been starting, I would have seen it by now, no?"

Kind of hard to argue with 22 years of success.......

If you have the opportunity to create a dedicated start bank, for reasonable cost, by all means go for it. If it causes big expense, and lots of modifications, then perhaps continue with what has been being done for 40+ years..