Originally Posted by s/v Jedi
Okay, I like the setup with the combiner, make sure it is FET based to minimize losses. Also, plan for how to deal with equipment failures, i.e. what to do if the combiner fails. Maybe a switch or two can bypass it for manual operation, preventing the need for rewiring while underway etc.
It a Victron Cytrix battery combiner with combiner+isolater switches, means I can combine both side or isolate Start STB from STB and BB from BB.
Thats how it is already installed by former owner (without fuses
which i will add too) so 2x72AH lead in STB and DC2DC eg 70A Sterling or 2x30A Victrons or? and job done.
Originally Posted by s/v Jedi
Also, with your setup I would install a 360W Orion dc-dc converter near each engine. This gives you 60A rather than 70A when either or both engines run but also it still gives 30A when one Orion would fail
(I have two as well)
well thats a business case in the end...
I am massivly overpowered but have no daggerboards means sailing close AWA >55 degrees means i am motorsailng because i get +2kn/can keep heading at 1l/h motoring with 1 engine @1300RPM is a noBrainer. And seperate well isolated engine rooms so you nearly don't hear the engine at all. means that happens more often then I like running at 1300RPM for 10h or more...
thats why i care about maxing one alternator out, i have it and extra AH in at passage
is always good. An overhauled replacment 115A original costs 200Euro so maxing it out&stressing&reducing lifespan is ok, i have a spare.
1x Stering is 450Euro and delivering 70A, so 10h motoring is 700AH and net 550AH in the bank
2x Victron is 600Euro and really delivering 2x25-27A=50-54A, doing eg 10h motorsailing I have 500-540AH, around 350A net in the bank
so using Victron is 150Euro more expensive for 200AH less in the bank
plus the sterling is no cooking brick (at least my buddies 12V 60A one) compared to Victrons.
But I hope to find maybe cheaper 12-24V DC2DC eg 2oA ones for around 100Euro maybe..so i get several as backup. or good deal on Victrons...
I will test in parallel a 70Euro 80A chinese boost converter variable input 9-17V and 28,0V output controlled by the Electrodacus BMS, thats backup. My buddy has the same model/manufacturer in the other direction 24V to 12V in 120A version for his anchor
whinch (will use that too) which is hard on it being 900W and going strong for 2 years now. Will be in med
this season so can test it out and easy replace if needed. Charged LFP for 20 years with a fix voltage power supply, no problem.
2nd I am working on a mod kit (which i also plan to sell for optimising the rum
kitty, have already 10 that want such a kit) for the 115A Mitsubishi on Volvos to gear
it higher+Nordkyn VSR 200 regulator
and will get around 100A from it instead of 80A constant charging. Main reason I am overpowered with huge 3-blade 18x13 FOFF (instead tiny 12x11 2 blade) so engines run on low rpm
frequent so gearing up alternator makes sense by default, the 115A Mitsubshi has some reserves hidden adding to that too (i have construction plans and Mitsubshi intel so I know the 100A goal is realistic) and there is even a 200A aftermarket version where the kit could fit too, so realistic 140A could be possible for a budget
you won't even get just the 24V/70A alternator that will deliver 40A@24V. Lets see what works...
Depending on the results here I might even go dual voltage house banks and erase the lead completly and start from 12V house LFP or LTO.
So one road/final solution in maybe a year or 2 could be keep both 12V 115A delivering 2x100A and max them out with each a 70A+20A DC2DC (or eg 2x40A/4x20A when avaliable) and LTO starters.
or the other way have 24V/min 70A alternators with nordkyn VSR regulator
on both engines charging house+24V starters
or maybe both (modified 12V and 24V alts with 12V starters and DC2DC), depends on the costs and what works in the end.
First get running what I have with the 24V house, then I will try to modifiy/adapt what I have for max output and 2nd add new if make sense from costs/output gain.