Maintaining battery terminals

[Col_T]

The simple question is - clean all items to be attached to a terminal and then smear the whole lot with Vaseline, or clean and then Vaseline each individual item? Also, presumably it is okay to clean the AC and DC hull bonding points in the same way?

 

The slightly more difficult question is process. Isolate the batteries (by turning of all isolator switches, the inverter and unplugging the shore-line) and then disconnect the battery interconnect cables, but which should be disconnected first, +ve cable or -ve?

 

Finally, I know that the Smartgauge site has an explanation of why the domestic and engine -ves are connected, but I can't find it for the life of me! I'd be grateful if someone could provide an explanation or the link to the page.

 

Oh, finally, finally. Is there a suggested maximum number of connections to a single post? Reason for asking is trying to understand the battery interconnect diagrams on the Smartgauge site for my set-up (5 x 110Ah): option 3 would appear to need 7 cables connecting to a single post (1 for each battery, 1 for the inverter/charger connection and 1 for all the loads) which, to my simple mind, seems wrong!

 

Ah, and another thing, and just out of curiosity, as I don't have such a device. Would a Smartgauge be connected to an individual battery in the above case, or to the single post that all 7 other connectors use?

 

That's it for now, though I'm sure I'll think of something else as soon as hit 'submit'!

 

 

Col_t

[nicknorman]

I would clean and smear each item in Vaseline or prefereably, silicone grease. That includes the mating surfaces of the connections. Which seems a bit odd but it does work! Otherwise the tiny voids in the mating surfaces will harbour moisture and corrode.

 

There are arguments both ways about which to disconnect first but I would disconnect the +ve first. It is also worth wrapping the spanner in tape just in case you get it wrong and touch something you shouldn't with it (not the actual bit in which the nut sits).

 

Domestic and engine negatives have to be connected if there is just one alternator and a split charge system, since each battery has to have a negative circuit as well as a positive circuit. You could either connect the negatives at the battery bank, or take a negative from the domestic bank, and a negative from the engine battery, to the alternator negative (and starter negative for the engine battery) - but normally these are all connected at the engine so it doesn't matter. Only if you have a shunt for an AH counter or ammeter do you NOT connect the engine battery negative directly to the domestic battery -ve.

 

When you connect a number of ring connections to a stud, the current tends to flow through the faces of the ring connections rather than the stud. So it can be helpful to think about the order in which you put the ring connections, ie the high current ones all next to each other in the middle, any lower current ones at one end or the other. But yes, if there are a lot of ring connections there might be some issues with resistance between the furthest away ones but nothing is perfect!

[Geo]

Do wear protective gloves

 

Do make sure that you clean the contact surface to a bright finish. The object of putting a grease on the terminals is to exclude air, which carries moisture, which causes corrosion on the terminal, which causes bad contact. You do not need a lot of grease; just rub it thoroughly into all the surfaces before you put the connection together.

 

The maximum number of terminations of a single battery point depends. Generally the recommend is 4. If you put the heaviest current connector on first and work down to the smallest current. I have see a couple more put on successfully. However many are put on the nut that secures them must be fully on when tight with the bolt thread at the very least just through the nut.

[Murflynn]

how did we ever manage in the good bad old days without elfin safety?

[nicknorman]

how did we ever manage in the good bad old days without elfin safety?

We got a new battery for the plane the other week, it came with the acid in bottles to be added by us. So I open the first bottle, cut open the paper seal at the top and go to pick it up to pour (via a paper funnel) into the battery cells. Oops, the bottle was fuller and softer than I thought and my squeezing it caused acid to plop out of the top and all over my hand, the bench, the battery and a tiny bit splashed on my toolbox. Grrrr. But no impact on my hand - I just washed it off, it didn't even sting. And miraculously, no holes in my clothes. YET!

[rusty69]

We got a new battery for the plane the other week, it came with the acid in bottles to be added by us. So I open the first bottle, cut open the paper seal at the top and go to pick it up to pour (via a paper funnel) into the battery cells. Oops, the bottle was fuller and softer than I thought and my squeezing it caused acid to plop out of the top and all over my hand, the bench, the battery and a tiny bit splashed on my toolbox. Grrrr. But no impact on my hand - I just washed it off, it didn't even sting. And miraculously, no holes in my clothes. YET!

My dad has just brought yet another share in a glider (i've lost count now). This one apparently has an electric motor and some kind of clever battery arrangement. Hopefully its a sealed battery.

[ditchcrawler]

And miraculously, no holes in my clothes. YET!

Give it time

[Geo]

We got a new battery for the plane the other week, it came with the acid in bottles to be added by us. So I open the first bottle, cut open the paper seal at the top and go to pick it up to pour (via a paper funnel) into the battery cells. Oops, the bottle was fuller and softer than I thought and my squeezing it caused acid to plop out of the top and all over my hand, the bench, the battery and a tiny bit splashed on my toolbox. Grrrr. But no impact on my hand - I just washed it off, it didn't even sting. And miraculously, no holes in my clothes. YET!

The acid when clean terminals is a very unlikely problem. Think about the lead, plus cadmium in the terminations plating. Cleaning with bare hand, very fine particles of the metal can get into the skin and be absorbed.

 

Clothes don't matter they can be replaced

[cuthound]

We got a new battery for the plane the other week, it came with the acid in bottles to be added by us. So I open the first bottle, cut open the paper seal at the top and go to pick it up to pour (via a paper funnel) into the battery cells. Oops, the bottle was fuller and softer than I thought and my squeezing it caused acid to plop out of the top and all over my hand, the bench, the battery and a tiny bit splashed on my toolbox. Grrrr. But no impact on my hand - I just washed it off, it didn't even sting. And miraculously, no holes in my clothes. YET!

Have you washed the clothes yet? When I regularly worked with batteries, many moons ago, I found the holes mysteriously appeared once the clothes had been washed. I don't know why.

 

Possibly Geo was suggesting gloves to protect against the accidental ingestion of lead dust, when making the battery post bright, rather than acid burns?

[Geo]

how did we ever manage in the good bad old days without elfin safety?

We had a lot of lead & the like poisonings

[nicknorman]

Have you washed the clothes yet? When I regularly worked with batteries, many moons ago, I found the holes mysteriously appeared once the clothes had been washed. I don't know why.

Possibly Geo was suggesting gloves to protect against the accidental ingestion of lead dust, when making the battery post bright, rather than acid burns?

Yes I've washed my jeans, so far so good!

[Jrtm]

I tend to clean right up and cover in sturn gland grease as its waterproof and saves having to go out and by another type of grease

[Murflynn]

We had a lot of lead & the like poisonings

who is we?

[ditchcrawler]

who is we?

I think he means the working population before the HSAW act.

[blackrose]

I would clean and smear each item in Vaseline or prefereably, silicone grease. That includes the mating surfaces of the connections. Which seems a bit odd but it does work! Otherwise the tiny voids in the mating surfaces will harbour moisture and corrode.

 

I've never really understood this. So much is made about the importance of clean battery posts and terminals to ensure minimal electrical resistance, so wouldn't smearing Vaseline all over them prior to reconnecting insulate and increase the resistance between the mating surfaces? Or are Vaseline, silicone grease, etc, good electrical conductors? It seems counter-intuitive to me.

 

I bought some Durite battery post grease in a small tube but only used it once.

Edited November 30, 2016 by blackrose

[nicknorman]

I've never really understood this. So much is made about the importance of clean battery posts and terminals to ensure minimal resistance, so wouldn't smearing Vaseline all over them prior to reconnecting insulate and increase the resistance between the mating surfaces - or are Vaseline, silicone grease, etc, good electrical conductors? It seems counter-intuitive me.

I bought some Durite battery post grease in a small tube but only used it once.

I agree it does seem counter-intuitive but it seems to work! The mating surfaces are in fact quite rough at microscopic level and the grease will be pushed away from the miriad tiny points of contact, but remain in the voids to prevent any exfoliating corrosion.

[blackrose]

This is the stuff I have. Is it any better, worse than Vaseline or silicone grease?

 

http://m.ebay.co.uk/itm/DURITE-ANTI-CORRODE-NO-CORRODE-BATTERY-TERMINAL-GEL-20ML-TUBE-/250532262831

[Geo]

I've never really understood this. So much is made about the importance of clean battery posts and terminals to ensure minimal electrical resistance, so wouldn't smearing Vaseline all over them prior to reconnecting insulate and increase the resistance between the mating surfaces? Or are Vaseline, silicone grease, etc, good electrical conductors? It seems counter-intuitive to me.

 

I bought some Durite battery post grease in a small tube but only used it once.

 

It is something people who have not been around batteries find difficult to accept. I'll try to explain I have to go back in my mind. The corrosion that one gets on battery terminals is caused by electrolysis of water and lead into the white or green compound you sometimes on battery terminal when they are playing up. . For there to be electrolysis, there has to be water. The air carries water, and in the UK with the air humidity varying between about 50% & 100% there is plenty of water for electrolysis to help the corrosion along. Battery terminals are not lovely machined surfaces that mate together perfectly or on which a lot of pressure can be applied to force them together. So even when cleaned there are gaps between the mating surfaces, not much but enough for air with its moisture to get into and start the corrosion, which will gradually work its way into the areas that are actually touching and cause a high resistance etc. The solution is to apply something to the metals that stops the air, hence water, getting to it, that is a smear of petroleum jelly. Petroleum jelly I understand because in those areas where the contact match perfectly it is apparently liquid enough under pressure to flow out of the way and it yet it stays put blocking the air in other areas that do not touch.

 

The use of silicone and the like I have not had much success with they do not seem to flow out of the area where contact is made, as well as petroleum jelly. There have been greases with copper etc added, not enough to pass a current they work well enough. But petroleum jelly seems to work best overall.

This is the stuff I have. Is it any better, worse than Vaseline or silicone grease?

 

http://m.ebay.co.uk/itm/DURITE-ANTI-CORRODE-NO-CORRODE-BATTERY-TERMINAL-GEL-20ML-TUBE-/250532262831

 

I have not the foggiest, no idea what is in it etc.

[ditchcrawler]

This is the stuff I have. Is it any better, worse than Vaseline or silicone grease?

 

http://m.ebay.co.uk/itm/DURITE-ANTI-CORRODE-NO-CORRODE-BATTERY-TERMINAL-GEL-20ML-TUBE-/250532262831

We use to use something very similar made by Holt's but we bought it by the tin full, but we did have several batteries to look after.

[Geo]

I think he means the working population before the HSAW act.

 

The whole population were affected.

No considerably before that when the UK started to ban lead in paints, lead pipes in houses etc, by voluntary agreement at first, probably back in the 60s/70s think that is before HSaW Act. Think the first Act from memory was mid 70s, trying to remember where I was working when it came out, somewhere about there. Lead in paint, lead pipes in houses had gone or were considerably reduce before then. 50% of some paints was lead in the 50s. Think the final nail was EU stuff through the 90s.

Edited November 30, 2016 by Geo

[Peter Reed]

 

The whole population were affected.

No considerably before that when the UK started to ban lead in paints, lead pipes in houses etc, by voluntary agreement at first, probably back in the 60s/70s think that is before HSaW Act. Think the first Act from memory was mid 70s, trying to remember where I was working when it came out, somewhere about there. Lead in paint, lead pipes in houses had gone or were considerably reduce before then. 50% of some paints was lead in the 50s. Think the final nail was EU stuff through the 90s.

Lead nails? there's a surprise

[Geo]

Lead nails? there's a surprise

 

I know I am tired etc not sure what you are trying to say ?

[WotEver]

 

I know I am tired etc not sure what you are trying to say ?

It was a joke about your last line: "The final nail..."

[blackrose]

There seem to be some differences of opinion on whether to put grease between posts and terminals on this US mechanics forum.

 

http://mechanics.stackexchange.com/questions/113/how-do-i-apply-dielectric-grease-to-my-battery

 

Personally I think I'd only apply grease to the assembled post and terminal. After all, if you cover the assembly, apart from the tiny bits of air and moisture that are already in the microscopic gaps, no more is going to be able to get in, hence no build up of corrosion. But that means you have to thoroughly clean posts and terminals anytime you take them apart, before putting them back together.

[Geo]

It was a joke about your last line: "The final nail..."

 

Ah so now you know what another poster's intentions and meanings are or is the poster you in another guise