I've read over most of the posts on here for battery upgrades, as the "multipurpose marine and RV" batteries that came with our boat appear to be fading from usefulness. The previous owners installed a third battery (identical to the other two) with a switch to isolate it unless needed, so we have Battery 1 and 2 on the electrical panel selector, then battery 3 on an individual switch. On shore power, we have a Mastervolt 12/40-3 charger that is connected to all 3 batteries. The boat came with a balmar alternator and ARS-4 external regulator.
My thought is to set up the system much like MaineSail's recommendations with battery 1 as a house bank of 4 6-volt golf cart batteries with the alternator connected to the A-post to prevent diode failure if someone gets switchy with the engine running, and battery 2 as a reserve bank. If we do this, I would imagine we need to install an echo charger to allow the reserve bank to charge from the house bank, is that correct? How does the echo charger interact with the multi-bank charger already installed, or should the echo only be used with a dedicated starting battery that is not connected to a shore power charger.
Do you make it a point to 'cycle' the reserve bank occasionally by operating on "both" or #2 bank.
maybe some of these have already been answered, but I didn't see these items specifically addressed.
Dan & Amanda Reed
1989 Catalina 36 #947 Miss America
Fin Keel Std Rig
FL Panhandle
See this discussion: www.catalina36.org/forum/technical-discussion/battery-compartment-wiring
and https://www.catalina36.org/forum/technical-discussion/drowning-wiring-info
At comment # 16 www.catalina36.org/comment/47354#comment-47354 I diagrammed the system we ultimately came up with (see attachment to this posting), after consulting with the collective wisdom of Mainesail and others on this site. It works quite well for us.
As you will see, everything is fed to the positive side of the house bank (actually, most of the connections are now at the combiner relay, but same difference). The charging of the reserve/start battery is all through an automatic combiner relay (identified on the sketch as "ACR relay"), which combines the house and reserve banks once the voltage levels are high enough to charge both.
In the 5 years since we did this modification, we have NEVER had to do anything with the battery switch; we just leave it on "1". Its basically a "set it and forget" system. There is no need to "cycle" the reserve bank because it gets exercised every time we start the engine, and then quickly recharged from either the alternator or charger (because you really don't draw down that many amp hours to run the glow plugs and crank the starter a few seconds). In other words, it eliminates the need to remember to fool around with the battery switch now and then. And, by wiring the alternator output directly to the house bank, the risk of inadvertently frying the diodes is eliminated.
If the house bank ever died, we could run the boat off the reserve by putting the battery switch on "2" (thus isolating off the house bank).
If the reserve bank ever died, we could start the engine by putting the battery switch on "both", and turning off the "starter disconnect switch" (thus isolating off the reserve bank).
Matthew Chachère
s/v ¡Que Chévere!
(Formerly 1985 C36 MKI #466 tall rig fin keel M25)
2006 Catalina Morgan 440 #30.
Homeported in eastern Long Island, NY
Properly installed, a Xantrex Echo Charger is a "voltage follower" designed to bleed power from your house bank into your start bank when the voltage at your house bank is higher than your start bank. Somewhat similar in what is trying to be accomplished, a VSR (voltage sensing relay) combines your house and start banks together when one bank exceeds a specific voltage and isolates the banks when one bank drops below a specific voltage. Most VSRs let you choose which bank to use as the voltage trigger for the two actions. Lots of opinions on what bank to use as the trigger, i.e., house or start.
Neither device has any smarts about charge curves, relying upon your charging sources to properly charge and condition your battery banks. An Echo Charger is an easy DIY install. A VSR install is more difficult as you're dealing with heavy cables and have to consider your manual isolate/combine strategy that can inadvertently defeat what a VSR is trying to do. On our boat we went with a VSR, chose house as the trigger, and eliminated the manual isolate/combine ability all together.
I don't seen any benefit to cycle the banks, i.e., use the start bank for house duties. Perhaps if you wanted to test your starting battery to see if it could sustain something other than a quick start burst, then maybe....
Nick Caballero
Retired C36/375IA Mk II Technical Editor
Hi Nick:
Revisiting this, with the Echo charge being a "voltage follower", would it essentially do nothing when the boat is plugged in and the charger turned on? Or would the echo need to be isolated when the charger is turned on?
Dan & Amanda Reed
1989 Catalina 36 #947 Miss America
Fin Keel Std Rig
FL Panhandle
[quote=danno]Hi Nick:
Revisiting this, with the Echo charge being a "voltage follower", would it essentially do nothing when the boat is plugged in and the charger turned on? Or would the echo need to be isolated when the charger is turned on?
[/quote]
Hey Danno. The Echo Charger will supply power to the starting bank whenever ANY charging source is charging your house bank AND your starting bank is in a state that can utilize the charge i.e., SOC of the start bank is less than the house bank. It does not matter if the charging source to the house battery is the dockside battery charger, alternator, wind, or solar. Fair to note you can defeat the intended use of the Echo Charge by having the house and start banks manually combined, but this is true of VSRs too.
You can operate a dockside charger and the Echo Charger in parallel. This is is true for all charging sources. For properly-connected dual-output chargers, fair to note that the Echo Charger likely won't be adding any charge to the starter bank because the dockside charger output will typically be at a higher level and thus doing all the work.
Nick Caballero
Retired C36/375IA Mk II Technical Editor
Nick:
Thanks for the great feedback. That definitely allays my concerns. Essentially I want to use the Echo to charge when motoring, but still have the advantage of maintaining the battery properly with the onboard charger when dockside.
From studying historic forum posts, it appears my simplest route is to:
Other than installing a battery monitor (future project when boat-bucks allow), is there anything I've missed in this overall scenario?
Dan & Amanda Reed
1989 Catalina 36 #947 Miss America
Fin Keel Std Rig
FL Panhandle
Thanks for the feedback, gents. We've just spent the weekend on the boat, and I spent some time chasing down more of the electrical system. The system had been added to quite a bit over the years without any subtractions (that could become its own thread loaded with masking tape, household wire and zip-ties). The new electrical panel, some new terminal strips, and a solid day with a meter and a label machine helped sort much of that out.
It looks like the Echo-charge is an easy add to the system, and from what I understand above will not interfere with the multi-bank charger, so that's a definite add to the list. I reckon that makes the "fancy" multi-bank charger a bit of overkill, but glad to have the redundancy. I did away with the worn out "multi-use" batteries and put in 4 GC-2 golf cart batteries for the house and 2 for the reserve (still some modifications to be made in the battery wells, but it's getting there). Replaced several of the vise-and-plier crimped THHN cables with soldered and heat shrink protected marine grade 4-AWG. I ran out of terminal lugs, so I've got a handful of connections yet to re-do (I figure on re-terminating all the #4 wire) and hopefully improve the longevity and performance of the system. Some pictures attached.
old batteries 1 and 2
New battery #1
Old electrical system with semi-functional circuit protection
New electrical panel from Catalina Direct... a perfect fit, and fully protected.
Dan & Amanda Reed
1989 Catalina 36 #947 Miss America
Fin Keel Std Rig
FL Panhandle
Nice work!
Nick Caballero
Retired C36/375IA Mk II Technical Editor
Thanks, Nick! She's a work in progress, but definitely coming along! and thanks to all for the helpful advice and shared knowledge. The C36ia membership has paid dividends thus far!
Dan & Amanda Reed
1989 Catalina 36 #947 Miss America
Fin Keel Std Rig
FL Panhandle