dual purpose engine start/domestic batteries

I must say that my one experience with Victron was disappointing. I bought a Victron Multiplus inverter/charger with battery monitor for my previous boat in Croatia. It packed up within the 12 month warranty period but Victron refused to ship another one to Croatia to replace it and instead insisted that the unit was returned to the UK for assessment and if possible, repair. Yes I suppose that was within the letter of their warranty but it meant that my boat would be effectively disabled for several weeks at the height of the season. To avoid this I very reluctantly bought a new unit from their Croatian dealer and I was up and running again in about 3 days but Victron's lack of interest in my predicament left a bad taste in my mouth
 
Right. Had the Spanish electrical bods on this morning.

Turns out my batteries are as follows:

Port bank of 5 do the services
6th in the port side does the genset
6 on the starboard side do engine start for both engines.

5 domestic batteries are in good condition, the guy thinks fairly new.
Generator battery ok but maybe coming up to replacement (though genset starts ok)

5 (missing one due to a catastrophic failure) engine start batteries all completely knackered. Forward three do port, rear three (now 2) do starboard. New batteries ordered - delivery on Friday or Monday. Electrical man coming back to then test both chargers and see what's up with the panel charger control read out.

It has become apparent I need some form of battery monitor so will look at the victron stuff suggested
 
Ok, but did he suggest to connect those 4 batteries in 2 banks of 2 batteries connected in parallel, each dedicated to one engine, or to connect the 4 batteries in parallel, hence having one bank serving both engines?
What I meant is that regardless of how much power it takes to start the engines (and if 2 1000cca batteries are enough, fine, it's pointless to use more), I would keep only one single bank for starting either port or stbd engine.
You don't need to start them simultaneously, do you? :)

And the backup is obviously provided by the parallel switch.
Incidentally, I suppose that in your current configuration, that switch connects in parallel the 2 starting battery banks.
But there's no reason why you couldn't rewire it and connect in parallel the starting with the domestic batteries - though obviously that has to be just a momentary connection, strictly for as long as necessary to crank the engines.
 
Currently I have a switch on the dash that connects two starting banks
I also gave a breaker that connects the whole lot.

Spanish sparky suggests setting up as 2x2 batteries keeping the dash link if needed.
This way we should be always able to start one motor either from its own battery's, all 4 engine start batteries or all 10 boat batteries
 
Fairenuff, but that's an OTT redundancy, imho.
Are you carrying around also a second tender outboard, just in case.... :confused: :rolleyes:
 
Whitelighter said:
Right. Had the Spanish electrical bods on this morning.
Click to expand...
Did he explain how the 2 chargers were set up ie can one or other charger charge both battery banks or does each battery bank have a dedicated charger (which seems odd to me)
 
Deleted User said:
Did he explain how the 2 chargers were set up ie can one or other charger charge both battery banks or does each battery bank have a dedicated charger (which seems odd to me)
Click to expand...

Electrical man is going to do a complete system test once new batteries are here. He said no point until that bit is working.
He did say the Chargers were good, and didn't seem phased by there being 2
 
Whitelighter said:
Electrical man is going to do a complete system test once new batteries are here. He said no point until that bit is working.
He did say the Chargers were good, and didn't seem phased by there being 2
Click to expand...

All sounds good and lets hope the 4 new batteries is the end of the matter. Interested to know how the chargers are set up though
 
Jez I don't want to throw in any spanners but make sure they also check which engine alternator charges which engine battery bank when under way...! With separate banks serving each engine this should be straight forward.

I only have one high CCA battery dedicated to my port engine which when under way is charged by port engine alternator and when on shore power, by one of three charging circuits from my charger.

I have a twin battery bank covering service and starboard engine starting, also high CCA, as this bank also powers my stern-thruster. This is charged by stb engine alternator and when on shore power by the second of three charging circuits from my charger.

The third charger circuit serves a single battery dedicated to my bow-thruster.

Plus a link switch to combine engine starting banks.
 
Good point about alternators, with 3 separate battery banks you are going to need 3 alternators or as I suspect a diode bridge between two banks so 1 alternator does it engine and the service bank and the other just its engine.
 
Yep, that's what I thought, a split diode with one alternator charging one engine bank and the service bank. There is a volt drop across diodes which reduces charge efficiency, I wonder if three banks are really necessary, other than the obvious, beer fridge(s) draining the service bank which is highly likely on Jez's boat:cool:.

Another thing to consider is whether you have inverters fitted, if so, consider what bank they take their supply from, on my boat its the starboard engine/service battery bank.

The electricians will be able to sort/advise 'm sure.
 
Update (hopefully the final one):

My 5 Numax CXV31F batteries arrived today. I ordered 5 - 4 for the two engines arranged in a 2+2 configuration and 1 spare/new genset battery. They are 110Ah with 1000CcA at 0 degrees.

Wired up the four batteries, after cleaning up the terminals on the link cables and starter leads, with no shore power, chargers off and service batteries isolated both engines started instantly.

Hopefully problem solved
 
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