looks good and I only have a few observations.
You show switches on Echo, Solar
, Alt etc.. These are not a bad idea but that is a lot of switches to remember after servicing the engine etc.. Also be sure your solar regulator
is okay with switching on the load side not the panel side. Some manufacturers prefer load and some prefer panel side. Perhaps easier when working on the system to just pull the bank fuse.
The MRBF dual post I would switch to the house batt and run the alt to one post and the loads to the other. Use the in-line Echo fuse on the start battery.
You don't specify wire gauges, bank size or fuse sizes. That info should ideally be there so we can comment on the suitability, sizing ampacity etc ..
You don't show a shunt which would indicate lack of a battery monitor
or ammeter. If you do have one be sure to wire it in there properly. Perhaps 7 out of 10 I see installed by pro's and DIY's are wired incorrectly (shunt wiring) and 9.5 out of 10 are programmed incorrectly. When set up correctly, wired correctly and used correctly they are great tools. When set up and installed poorly, they can be misleading.
The wire from your house bank positive all the way to the starter should all be the SAME SIZE and this is already protected by the battery bank MRBF fuse. There is no need for additional fusing between the battery and the starter as it is already covered.. Where you step down for house loads, after the "C" post, then you will need a different sized fuse, if not using the same gauge wire to the DC panel. Every fuse adds voltage drop so I would suggest removing the buss bar fuse going to the #1 position and the ANL after the "C" post to the starter.
There are many ways to wire your sailboats batteries and I am often taken out of context when it comes to wiring
As a marine
electrician I see it all and wire it every way from Sunday. I often treat sailboats differently than trawlers and trawlers differently from large inboard sport fishing
boats and large sport fishing
boats differently from outboard
powered boats. Each type of boat has its own unique set of uses and issues to deal with.
In an ideal world every boat would have full redundancy so either bank could be used for either purpose, if needed. I always try to design systems with what you might call a "spare tire".....
If you have a suitable
house bank, usually 200Ah+, and suitable
wiring, then using it for starting is an easy solution if you already have a 1/2/BOTH switch installed on-board. It avoids the needless switching back and forth so many folks believe they need to do between a "house" and "start" bank..
bank of house batteries, with good wiring and connections, should EASILY start a small sailboat motor
without dropping electronics
all the way down to 50% SOC. Starting these motors for a 200+ Ah bank is like Lance Armstrong getting up out of a chair, not much effort at all.
It is a complete fallacy that you need "starting batteries" to start a sailboat aux diesel
engine. Any suitable deep cycle house bank will do this with ease and will usually out last a cheap
thin plate starting battery.
If you decide to use the house bank as an everything
bank the start battery can't be ignored and should be checked from time to time. Every now and then start on that battery to check it or run the inverter
from it to give it a good work out.
If your house bank is dropping out electronics, while starting, at 50% SOC, it is: A) Not a healthy bank B) Not suitably sized to do both deep cycle and starting C) You have wiring and voltage drop issues in the system compounded onto battery voltage sag..
You have two choices in this situation, either address the issues & short comings or re-wire for dedicated start battery. Simple stuff.
There are millions of 1/2/BOTH switches out there and as of a few months ago, other than the ON/OFF, the 1/2/BOTH was still Blue Sea's #1 selling battery switch and it was pretty close numbers wise to the ON/OFF.... The vast majority of boat builders still use these switches. It can be an excellent switch, and there are many good ways to use it, if you want to. This LINK
takes a deep look into the 1/2/BOTH Switch
One of my favorite switch configurations, if starting from scratch, is three properly wired ON/OFF switches.. One for HOUSE one for START and one for emergency
cross connect. With this set up each bank can be 100% isolated and the other bank used in an emergency
. Unfortunately many boats are not well suited to retrofit this three switch method, especially with the number of battery switches out there mounted in custom panels
An option that takes from that idea (three on/off's) is keeping the existing 1/2/BOTH and using it in conjunction with an additional ON/OFF. The ON/OFF serves as a dedicated starting battery switch and the #1 position serves as HOUSE. The other positions are there for complete system redundancy & isolation.
For sailboats that already have a 1/2/BOTH installed it can make life a lot easier to just use it as an ON/OFF and let an Echo or combiner do the rest, if your bank and wiring are up to the task.
The only switch I really don't really care for all that much, for deep cycling applications, is the Dual Circuit Plus. I am not a huge fan due to the lack of redundancy and the only safety
measure being to combine
a potentially bad bank with a good one, unless you physically get in there and disconnect stuff...
The DCP is a simple and easy switch, and this is a great feature, but not one that offers a lot of back up, isolation or redundancy measures.