Install almost finished. 8 x 400 Winston Cells in, setup as 12 volt 2P4S. Very nice and setup. Victon Multiplus charge charge profile changed and the Solar controllers changed, both working well. 5 x 110AH AGMs out.
Alternators are good at 115amps but I have changed what I was going to do. They are currently set to 14.3 volts and have an external voltage sense and basic temp regulation. You can get to the brushes
so its not too hard to tap into the field to "turn off" the charge, however, when you turn it off (in my case) the Volvo alarm
goes off as it thinks the alternator is dead. Yes you can alter this but a bit of a pain.
So the plan at this stage is:
I have split the charge bus from the load bus. (Good idea anyway).
I'm leaving one of the old AGM's as a start battery for the Port engine
. Always had one for Starboard.
I'm leaving the 2 alternators standard. Gives me 230 amps with both running.
I'm putting a charge splitter between the Port AGM
starter and the LifePO4 bank off the charge bus. There is already a battery combiner between Port and Starboard so when charging
everyone's getting a piece.
I'm putting a large contactor between the charge bus and the LifePO4 back that is driven by the High voltage relay circuit of the Victron BMV702 monitor
so at a set pack voltage it will disconnect all charge source to the LifePO4 bank only and reconnect when it reaches a lower set threshold. AT this stage it's pack voltage of 13.9 high and 13.2 low but easy to change and still a work in progress.
The disconnect shouldn't damage anything as any surge should be sucked up by the AGM
Starter that will still be connected. I will probably also connect this contactor to the HVC alarm
relay on the House power BMS just as a safety
but need to check the voltages its set to. Lots of alarms set between the BMS and and Victron BMV 702 so nothing bad should happen without the world knowing about it first.
This is this weekends job.
Early stages but very happy with the way it has all gone together and it seems to perform as advertised.
I understand peoples comments about BMS being needed or not (personal choice). I wanted one so I had the added safety
and flexibility for alarms and automatically cutting things off if needed. In theory these will never occur but nice to know that if needed they should. Yes I could use a simple Cell 8 or the settings on the BMV 702 but I like being spoiled for choice.