Richardcn

...makes an Ass out of U and Me

If the tank dimensions are correct but only 345 litres go in then is it possible that the tank has baffles fitted and that either the other sections are unvented (and thus airlocked) or the interconnections between the 3? sections were missed out at build? 345 litres is darned close to a third of what it should be!

External water tanks which will be subjected to warming to unhealthy levels in summer (let alone the bugs that might enter if not completely sealed) seem like a risky choice to me.

Thank you for sticking with me on this Tony. I have it now, it clicked after this more detailed explanation although a diagram probably would have helped earlier on. I'll remember that next time. Many thanks Richard

The shunt is a recent addition and the domestic alternator does not yet pass through it. The common negative from the engine frame currently goes directly to the starter battery and the domestic bank is linked in at that point. Once the batteries are rearranged that link will no longer exist and, as I see it, I can't take the current common negative to the shunt as it is also the (reverse) path for the starter motor. I'm probably not seeing the obvious or not explaining myself very well so apologises for that, it's been a very busy week so very tired.

Okay thanks. I understand how to wire a shunt but given the need to reposition the batteries and also to add the domestic alternator negative to the shunt I wanted to find the 'easiest' way without unnecessary expense. I think I've got it straight in my head now. Take the common negative (I may need a longer lead though) to the starter battery, run a new lead from starter battery to the shunt and then from the shunt to domestic bank. Is that correct? Seems obvious now I say it!

Could I 'split' the negative from the engine via a busbar near the batteries (one lead going to starter battery and one to the shunt)? That would save adding another long -ve lead.

So retain the current arrangement in the proposed new layout by using a longer (common) negative from engine frame to starter battery and an extended link lead from starter to leisure bank. How would I link the shunt though?

Thanks Tony. Yes the connections will be 'opposite corners' on the new layout, there was no point in worrying about it until then though given the long cable runs between the current leisures. My problem will be that in putting the 3 leisures neatly together the starter battery will have to be positioned further away off to the side. I can't see how I can stick with a common -ve in that layout , oh and something I forgot to mention, I have the battery monitor shunt to add into the equation. I need to split the negative somehow I imagine. Richard

Hi All Could you give us a bit of advice about re- wiring some batteries please. My stepson needs new leisure batteries on his new (to him) boat as they are 5/6 year old cheapo's with very little capacity remaining. His current set up is considerably less than optimal and so with the new batteries needs to come a new layout. His current arrangement is: - Beta JD3 with twin alternators - 175W Solar (doubling to 350W soon) - x4 Leisure batts (replacing with x3) - Single starter battery - 300W invertor (upgrading to 1600W) - Continuous cruiser liveaboard We aim to fit x3 new leisures where before there were x2 leisures and the starter batteries and then put the starter battery behind the side hatch ladder (where the other 2 leisures currently are). There will be all new 70mm2 wiring on the leisure batteries and I'm suggesting that he replaces his isolators with something newer and better. Everything seems fairly straightforward to me apart from the negative paths. The main alternator -ve goes to a common point on the engine frame (along with the starter -ve) and then onto the starter battery. The additional alternator doesn't appear to have a dedicated -ve so I assume it's using the engine frame and, again, using the (sizeable) -ve cable going to the starter battery. Thus (it appears that) both alternators and the starter motor use a common negative going solely to the starter battery. What is going to be the best way to deal with the -ve wiring with the proposed new arrangement (or maybe you can see a better alternative for the layout altogether). Your help would be really appreciated Hopefully the photos will help.

Hi All We finally made the journey off the Thames and onto the Lee via Paddington. Two and a half days of hard work but great fun. I didn't keep stats but approx 10 of the 43 locks were in our favour about 3 of them with gates open. Apart from Teddington and Brentford we only shared about 10 locks and had the Thames and her locks to ourselves bar 1. Of course, the only oncoming boats that we met were at blind bends and bridge oles, I kid you not! Many thanks for everybody's assistance in planning the adventure. Richard

Oh that's excellent!

Thanks. I guess I could nip along the Hertford on the bike to check for any problems before committing. It sounds like no contest otherwise.

Ah my mistake (and not my first in this post)!