mikeyboy1966

Plus some other bitsnbobs

Plan b, required removal of the old water tank mounts

My initial plan was to locate the new battery box in front of the engine, but,,,,, this would mean zero access to the raw water pump

With this in mind, live decided not to fuse the starter circuit,as he explains the pitfalls of doing so. but I will be looking to reduce the length of cabling to the isolator switches. work in progress,mk 1 version. now I have the battery isolator,and external regulator ive more questions than answers till I get down to the boat again.

Things are taking shape, I’ve spent some time looking at the seminars from pacific yacht systems. most informative. jeff cote seems to know his stuff ,without the normal waffle from YouTube vids. skip thru the intro bits.

Hmmm, not so sure about that. back to the m sport z3, lovely car, appreciating nicely,they are fetching 2x the money that they were when I had my 1999 2.8 and are likely to continue. iirc ,the m sport had NO traction control with 300 hp. the 2.8 could be lively,and that had tc. was excellent fun when you turned it off. tek it steady!!

I realise there is no “need” to fuse the starter cable, the battery isolators on the boat are not particularly close to the battery bank, id guess there is at least 3 to 4 metres of heavy duty starter cable between the batteries and solenoid/starter motor. if there is a valid reason NOT to fit a 500amp fuse,I’ll relocate the isolator,solenoid and associated wiring to minimise exposed wiring and components. As things stand ,all of this cable runs around the engine bay in close proximity to other wiring/combustible materials and parts that are earthed. Hence my concerns over a dead short circuit.

You’ve not read my post John , the pos and neg will exit the box from different sides so will not be taken off the same battery,there are two more batts to fit yet.and the through panel connections , the box needs to have a test fit on the boat to determine cable exits So I’ve not greased anything yet. as this is 1st fit,no point in getting oily mitts

Got it! all starter and batt cables will be 50 mm sq tinned. rated at @350 amp im only concerned with short circuit protection, id never just keep cranking an engine,if it doesn’t start as normal there is obviously a problem. thanks for the advice,very helpful

So in theory, I could fuse the main starter cable with a 500amp maxi fuse. so everything outside of the battery box would be protected from a dead short. hmm,will ponder.

I was pondering a 500 amp maxi fuse.

Quick question, does anyone know what sort of current a diesel starter motor is likely to draw on a cold start? im just considering the use of a mega fuse on the starter circuit, and what size fuse I’d need. ta

Melting point of lead 327deg melting point of solder (lead free) 217 degree personally I think a fire on board with timber,fibreglass ,plastics,upholstery and 50 gallons of fuel is going to ,by far exceed either of these numbers. but I’ll crimp anyway

Anyways. my plan. the “box” as you look at this photo is viewed from the rear. I intend to link all of the return/earth battery terminals together and exit the box with a through panel connector on the left side of the box at the front. and onto a bus bar. the 3 domestic battery positive will be linked and exit the box through the right hand side rear,again with a through panel connector. the domestic +ve will go to a mega fuse box then onto the isolator switch. the starter battery will also exit the box through the same connectors i may fit a mega fuse on this as well so basically everything outside of the “box” is fused in case of a dead short somewhere. the “box” will be fitted with a vent to the hull on the right hand side at the front. I need to test fit the box into position on the boat before I can start drilling/fitting etc, any obvious flaws in my plan?

Not disagreeing with the above but surely if there was a fire sufficient to melt the solder on top of the batteries it would melt the lead posts and the batteries would be on fire as well? so I recon the solder melting would not really be much of a issue

Righto, belt/braces I’ll crimp as well

Job done ✅

One down.

I decided to solder the ring terminals on . seemed to go well!

50mm sq tinned copper cable, reassuringly expensive

I bought 2x new batteries to go with the two I bought in the summer. 3xdomestic 1x starter

Next on the job list, new battery box, made from 18mm marine ply( though I must say I wasn’t overly impressed with the quality when compared to robbins elite) I’ve given it two coats of danboline so it’s ready for 1st fix electrics.

All interesting reading for a bit of fun, can we come at this from a different angle? clean slate. Assume these things. alternator currently fitted will stay 3x 120amp domestic batteries 1 x120 starter battery. boat has recently fitted vitron charger on shore power.(fairly high spec I think) if you had an ultimate spec system what would you fit,from alternator to batteries. there was mention in a previous post about “intelligent splitters” over blocking diodes but there was no elaboration. I have no need for inverters and the like, 1xcompressor fridge 1xcompressor coolbox lights all led. eberspacher heater 2xelectric loos 12v sockets and usb chargers. water pumps bilge pumps and any other normal stuff if I’ve not listed. performance and reliability are on my want list. I’d like to be confident to relocate the boat via sea crossings and tidal rivers ,so you guess where I’m coming from. im also not overly bothered about solar panels .

Linky no worky

I’ll take a looksee