Disconnecting a the batteries.

[rustydiver]

I need to do a bit off wire tidying up in the engine compartment and want to disconnect the batteries to be on the safe side.

Is it the same as a car disconnect the negitive one first.

Is there anything else I should look out for when doing it.

 

Or will it be ok to use the kill switch keys.

[Tiggs]

Yes, negative first is usually safer.

 

What is a kill switch key?

[RLWP]

Turn the isolators off (kill switches)

 

Richard

[nicknorman]

Presuming by "kill switch keys" you mean the battery Isolators? In which case, "probably" but be aware that in many installations, some circuits remain powered even with the Isolators off. These typically include the bilge pump, Combi inverter-charger, domestic alternator, Smartgauge etc. So to be ultra-sure, disconnect the batteries. Personally I'd just disconnect the +ve being very careful not to touch the spanner onto the hull (wrap the spanner in tape if you're clumsy!) since there can be stray -ve paths.

[Tiggs]

Personally I'd just disconnect the +ve being very careful not to touch the spanner onto the hull (wrap the spanner in tape if you're clumsy!) since there can be stray -ve paths.

 

That's why its best to disconnect the negative, it does not matter if the spanner touches the hull.

[nicknorman]

That's why its best to disconnect the negative, it does not matter if the spanner touches the hull.

In an ideal world I'd agree with you, but the reality is that boat wiring can be a bit messy with multiple return paths to the -ve - disconnecting the main -ve can result in the circuit still being maintained by the stray -ves. Anyway there are arguments both ways but IMO if you are not able to undo the +ve without creating a short, it's probably best not to be tinkering in the first place.

[Tony Brooks]

Seeing that far too many narrowboats have batteries fitted in direct contravention of the BMEA standards making it very difficult to absolutely ensure that you do not cause a short with the spanner and recognising the dangers Nick speaks of I would suggest the following:

 

Turn off ALL electrical equipment, double check this. Turn off the battery isolators. Disconnect the negative terminal first.

[bizzard]

If you have, say a rubber glove, rubber sock or even a condom at the ready, to immediately slip over whichever cable lug you decide to remove first. Or have two handy to slip over both cable lugs and can be secured with an elastic band, should be %100 safe then.

Edited June 9, 2016 by bizzard

[magnetman]

That's a great tip ! Always use protection.

 

Thanks for that

[Scholar Gypsy]

One more clarification/thought.

 

I think most terminals are like mine - a clamp on the battery terminal, with a vertical threaded bolt with Vaseline, spring washers, nuts etc.

 

I find it much easier to undo the nut (using a socket set) and remove the cables, and then disconnect the clamps at leisure (and if needed - may not be in your case) once the battery has been moved to a more accessible location.

[tonyt40]

Use fully insulated tools if you can get hold of them. In the industry where I work, any work on batteries is classed as live working and must be done under permit using fully insulated tools, full face visor and gloves.

 

http://cpc.farnell.com/insulated-tools-ltd/00007/tool-kit-delux-pro-insulated-29pc/dp/TL14822

 

I have a couple of single ended spanners in my tool kit. The only metal showing is the faces that touch the nut.

Edited June 12, 2016 by tonyt40

[rustydiver]

Thanks I managed all ok on Saturday used a small socket set and kept the the wooden top cover above the batteries between the batteries and boat just to be on the safe side.

[Chewbacka]

............................... where I work, any work on batteries is classed as live working and must be done under permit using fully insulated tools, full face visor and gloves................................

It must be interesting watching you change a torch battery where you work

[Fatjoff]

So, if you're replacing all your leisure batteries at the same time, do you disconnect all the negative terminals first before attempting to remove the positive ones? Or do you do one battery at a time, negative followed by positive terminal?

 

I ask, because this is my next job.

[Scholar Gypsy]

So, if you're replacing all your leisure batteries at the same time, do you disconnect all the negative terminals first before attempting to remove the positive ones? Or do you do one battery at a time, negative followed by positive terminal?

 

I ask, because this is my next job.

 

I would disconnect the negative supply cable from the battery bank first (and any others eg for smartgauges); and then the positive supply cable(s) (and any others eg for bilge pumps etc).

 

You then have N batteries that are connected in parallel, and I think you can disassemble the connecting cables more or less at will (as the negative side is no longer connected to the hull). Of course you still need to be careful not to short any negative terminal to any positive terminal, as that risks sparks flying ...

Edited June 14, 2016 by Scholar Gypsy

[PeterG]

I recently did this on our boat and I disconnected all positives first on all the batteries and then moved onto the negatives as from previous threads this appeared to me to be the best bet with the only downside being you needed to be careful not to earth out your spanner.

[bizzard]

When I was a kid Woolworths used to sell Melba chocolate tool sets and in them apart from a hammer, pliers, pincers and screw driver was a spanner which if my memory serves me right would have fitted battery lug nuts with no fear of shorting out. The chocolate was terrible though, it was gritty, undissolved sugar I expect, and had a greasy sheen on it. But we loved it.

[Murflynn]

When I was a kid Woolworths used to sell Melba chocolate tool sets and in them apart from a hammer, pliers, pincers and screw driver was a spanner which if my memory serves me right would have fitted battery lug nuts with no fear of shorting out. The chocolate was terrible though, it was gritty, undissolved sugar I expect, and had a greasy sheen on it. But we loved it.

is chocolate an adequate insulator?

 

I'd be worried about shorting out my fruit and nut.

[bizzard]

is chocolate an adequate insulator?

 

I'd be worried about shorting out my fruit and nut.

Care is needed. Used by Aero technicians I believe. You might have to Nestle up to the nut with caution or you could be blown away into another galaxy.

[the barnacle]

When I was a kid Woolworths used to sell Melba chocolate tool sets and in them apart from a hammer, pliers, pincers and screw driver was a spanner which if my memory serves me right would have fitted battery lug nuts with no fear of shorting out. The chocolate was terrible though, it was gritty, undissolved sugar I expect, and had a greasy sheen on it. But we loved it.

 

A delux set with Adjustable spanner

Edited June 14, 2016 by the barnacle

[tonyt40]

It must be interesting watching you change a torch battery where you work

We only use those eco torches with the winding handle now..... Health and safety......?

Edited June 14, 2016 by tonyt40

[Chewbacka]

We only use those economic torches with the winding handle now..... Health and safety......

Obviously you missed the dangers of RSI with excessive winding when doing the risk assessment

[Bee]

Whenever I have to carry batts. in the car or leave them uncovered I just stuff a couple of inches of old car heater hose over the poles/ lugs, theres always a few pieces lying around in the shed or in the battery box on the boat.

[cuthound]

A delux set with Adjustable spanner

Didn't they do a domestic set for gurlz? I think it had tea cups , oh and a teapot ☺

[ditchcrawler]

We only use those eco torches with the winding handle now..... Health and safety......

I was going to buy a solar one, but who wants to use a torch when the sun is shining?