bigal.nz

Right nice. I think we are close to that setup, and with some minor rewiring could be there.

PS: I never saw the link to Rod's drawing?

Sure - my question about four switches only arose out of a reference to IT - which I could not find earlier in the thread.

Ok - I will add to the diagram as I get time - but its worth adding there is a dedicated starter battery (which uses that combiner). You said IT suggested 4 switches? Switch Bank 1 Switch Bank 2 Switch ? Switch ?

Ok, so I got around to a bit more tracing of wires today. It looks like this (so far): The immediate issue I have realised is that I have been using that big black 1/2/Both/Off switch as a battery on/off switch (which it is I guess) - but the way it is wired this also disconnects the batteries from the solar charging over winter, so any parasitic discharge (like bilge pump and other always on stuff) would have slowly drained the batteries. Just a theory at this point - does it seem valid? I am not certain where the DC panel is connected yet - will trace that next time.

Nice diagram. You do it in Microsoft paint too? ????

Ok. A bit more investigating with multimeter revealed that in one bank one battery was at 6.3v and one at 4v giving me the 10.2v reading. I have removed those batteries and charging them at home. Still not sure how they got that low given the 300w solar panels we have on board. Will post a updated diagram later. Will a 6v golf cart gel cell battery survive going to 4v?

Thanks Matt. I will take some measurements. The old batt monitor was also reporting 10.2v on bank 1 so the new one is probably reading right. I just need to work it all out.

PS: You refer to shunts (plural), I only have one shunt. If its because those two -ve wires in my diagram are actually joined to the same stud at the shunt. So there is only 1 shunt measuring the total load. But I can measure voltage for each bank separately.

I think piece of the puzzle is going to be relevant - there is also one of these (stock photo) : However I have not traced how it is wired. How is a "combiner" different to just joining the +ve terminals and having a isolating switch? AG

Yep - that is the plan for tomorrow (find the voltage drop) - but the BMV712 is measuring at the terminals of bank 1 & 2 so there should be no reason for it to read different to the multimeter? Are your banks connected across the positive and negative terminals? I see the PO of this boat didn't connect the negative terminals until the shunt (could you join the negative side at the terminals?) and the positive terminals are separate wire runs until the battery selector switch.

Also, I have realised, if one batt is 6v and the other 6.4v then how can the output of that back be 10.2v? (6+6.4=12.4v)

Related to my BMV712 upgrade I have discovered battery bank1 is only readying 10.2v. (bank 2 @ 12.8v) The wiring looks like this: I am wondering how the alternator and solar charge controllers work with a 2 bank setup. I will trace the wires for alternator and solar when next on boat. But how should this be wired such that the charging controllers are "aware" of the state charge state of both banks? (and charge both banks) One of the batteries in bank 1 measured 6v the other 6.4v. Whats normal for a charged 6v batt?

That is heart breaking to watch. I really would think a great use of tax payer frigates would be to send them to sink anything with a harpoon.

That really sucks. I love that garbage barge. Guess the dinghy just got a new name ????. That said, if I see any boaties dumping rubbish, they will get a peice of my mind plus free delivery of there trash back onto there boat.

Awsome thanks.

Hello, I want to check the procedure for setting the Victron BMV712 batt monitor up. The manual (https://www.victronenergy.com/upload/documents/Manual-BMV-700-700H-702-712-EN-NL-FR-DE-ES-SE-PT-IT.pdf ) says that for setup, input the battery capacity in Ah (preferably using C20) and aux input. I have 4 6v batteries connected in series parallel (so effectively 2 x 12v batteries). Each battery (model 8GGC2) has a C20 of 180Ah. I presume I only add the Ah for the batteries in parallel? (thus entering 360) Cheers in advance AG

I did actually buy Penrite from Repco. List price was $32 - but the trade card took that down to $22. Shows how big the markup is.

Hi Folks, Whats a half decent coolant/antifreeze to add to our Perkins 4108 which has a heat exchanger? Doesnt have to be the gold plated stuff - just something decent. AG

That sucks. It was the best.

Actually the mod for the M12 and M18 chargers from 110 to 240v is very easy. I got the 110 M12 charger and have done it. Instructions here: https://www.youtube.com/watch?v=-Ed4frjioO4 I saved a lot getting the Milwaukee drill at home depo last time I was in the US, and the parts for the mod were about $15NZD online.

Guess I also need to factor in the 4G modem..... In my setup currently the only way to monitor anything on the n2k bus would be leaving the Vesper on. Not going to do that.

Looks like the max draw of a rasp pi is 1A at 5v. I guess at 12v the max draw would be something like 0.4 and if the pi is idle probably 0.2a. I think our batt bank is about 350Ah so that should easily cope.

Right thats good to know about 2degrees. I have 25Gb or some crazy cap with Vodafone, but no way to share it - I am thinking of changing. I actually think I RaspPi even in mid winter wouldnt kill the batteries as they are kept full by solar easily.

Right. I thought of doing something similar, but wasn't sure about the amount of power used by the Pi and 4G modem, and also it seemed a waste of money to pay for a dedicated sim to do that - the prepay data is still expensive? Would be nice if there was Wifi at the club house..... AG