How to top up a lead acid battery

[Dr Bob]

Ok, here's a dumb question. How do you top up a lead acid battery?

On my old lumpy water boat, it was easy. They were under a central chair. You could see right down the holes. Seeeeeemple.

Now with my nb, the batteries are concealed at the side of the engine bay (cruiser stern) with about 12" of clearance on top. Anyone bigger than a 7 year old child will have difficulty in getting to the back cells let alone seeing into them. I've been told not to let a 7 year old child do it. I can just get to the cells to pour the deionised water in, but I cant tell when I have reached the right fill level. A dentists mirror is not much use - torch, mirror, water, support - I need 4 hands for that.

Yesterday, I topped up the engine start battery that needed a good 100ml per cell and I poured it in until I could see the water at the top of the hole. I then stopped pouring and the 'high' water level at the top of the hole then dropped - I assume as it ran out of the slot in the plastic just below the top into the cell. Is this then the correct level of liquid in the battery or have I put too much in? The domestic bank doesnt look too bad for levels as estimated when doing some SG's but I need to be able to check and fill. What are your tricks for filling batteries when you cant see or get at them properly?

Edited December 17, 2017 by Dr Bob

[Tonka]

If you moor at Dunchurch pools see Mr Hull Cottage, he will make you a device which uses a syringe to do the job. Cant photo mine as it is on the boat

[MtB]

On 17/12/2017 at 12:34, Dr Bob said:

Ok, here's a dumb question. How do you top up a lead acid battery?

On my old lumpy water boat, it was easy. They were under a central chair. You could see right down the holes. Seeeeeemple.

Now with my nb, the batteries are concealed at the side of the engine bay (cruiser stern) with about 12" of clearance on top. Anyone bigger than a 7 year old child will have difficulty in getting to the back cells let alone seeing into them. I've been told not to let a 7 year old child do it. I can just get to the cells to pour the deionised water in, but I cant tell when I have reached the right fill level. A dentists mirror is not much use - torch, mirror, water, support - I need 4 hands for that.

Yesterday, I topped up the engine start battery that needed a good 100ml per cell and I poured it in until I could see the water at the top of the hole. I then stopped pouring and the 'high' water level at the top of the hole then dropped - I assume as it ran out of the slot in the plastic just below the top into the cell. Is this then the correct level of liquid in the battery or have I put too much in? The domestic bank doesnt look too bad for levels as estimated when doing some SG's but I need to be able to check and fill. What are your tricks for filling batteries when you cant see or get at them properly?

 

The way I solved this problem was to re-install the batteries in the back cabin on a bench at waist height with good lighting. That way I can obsess about them with ease. 

The downside is when you clip the covers back on afrter checking the levels/SGs etc, they splash a few microscopic droplets of acid at you. I know this as most of my clothes now have little holes in, about waist height.

[WotEver]

10 minutes ago, Dr Bob said:

have I put too much in?

Depends on the battery. Some like the electrolyte to just cover the plates, some have a plastic level indicator, some like the acid to be x mm below the hole. You’ll need to check the specs for your brand. 

[Boat&Bikes]

I use a durite battery filler. No mess and fills to correct level every time .

[WotEver]

There again, it’s not really critical if you’re a few mm high or low, it’s a very small percentage of overall volume. 

[Dr Bob]

12 minutes ago, ianali said:

I use a durite battery filler. No mess and fills to correct level every time .

Now that looks a good idea. I will have a look at them.

 

11 minutes ago, WotEver said:

There again, it’s not really critical if you’re a few mm high or low, it’s a very small percentage of overall volume. 

So is the method I described of filling to the top, which then drains down to a level I can't see, too full? That seems to be an easy way to do it.

[Chewbacka]

1 minute ago, Dr Bob said:

Now that looks a good idea. I will have a look at them.

 

So is the method I described of filling to the top, which then drains down to a level I can't see, too full? That seems to be an easy way to do it.

So where is it draining to??  Without knowing that answer, it is impossible to say.

[Dr Bob]

14 minutes ago, WotEver said:

Depends on the battery. Some like the electrolyte to just cover the plates, some have a plastic level indicator, some like the acid to be x mm below the hole. You’ll need to check the specs for your brand. 

My batteries are so cheap, they go 'quack' and don't have any specs. To be honest, I cant see a name on them they are so buried in the engine bay.

[MtB]

On 17/12/2017 at 13:03, Chewbacka said:

So where is it draining to??  Without knowing that answer, it is impossible to say.

 

Out through the little vent pipe el cheapo batteries often have, into the bilges I'd suspect. Not a Good Idea! 

[Dr Bob]

Just now, Chewbacka said:

So where is it draining to??  Without knowing that answer, it is impossible to say.

Inside each cell 'hole' there is a plastic sleeve with a slot. The slot allows water to enter the cell from the side of the plastic sleeve so the water rises in the plastic sleeve as it fills, you see it full, so stop pouring and the 'head ' of water in the sleeve drains into the cell. It looks like this design is to enable filling but I don't want to overfill.

3 minutes ago, Mike the Boilerman said:

 

Out through the little vent pipe el cheapo batteries often have, into the bilges I'd suspect. Not a Good Idea! 

No, it's back into the cell.

[WotEver]

11 minutes ago, Chewbacka said:

So where is it draining to??  Without knowing that answer, it is impossible to say.

What he said

[MtB]

On 17/12/2017 at 13:09, Dr Bob said:

 

No, it's back into the cell.

 

Well thats a relief. 

The only way to answer your question I think, is to disconnect and remove one of the batts so you can get a good look inside and see how this slotted tube arrangement actually works. And once a batt is out, have a better look for a label or make and model.

Another idea, can you get your phone in there to take a photo looking down into the cell? Then post it on here. Someone is quite likely to recognise it.

[Dr Bob]

2 minutes ago, Mike the Boilerman said:

l.

Another idea, can you get your phone in there to take a photo looking down into the cell? Then post it on here. Someone is quite likely to recognise it.

I will try and do that but it will be tomorrow as we aren't back till later. Good idea.

[WotEver]

11 minutes ago, Dr Bob said:

I will try and do that but it will be tomorrow as we aren't back till later. Good idea.

Don’t splash acid on the phone or it will dissolve

[luggsy]

One of these might do you https://www.ebay.co.uk/itm/Durite-0-149-50-Automatic-1-Litre-Battery-Filler-Bottle-Acid-Distilled-Water/121808174433?epid=1729742927&hash=item1c5c553d61:g:-agAAOSwYVlaDtK1

[Richard10002]

5 minutes ago, luggsy said:

One of these might do you https://www.ebay.co.uk/itm/Durite-0-149-50-Automatic-1-Litre-Battery-Filler-Bottle-Acid-Distilled-Water/121808174433?epid=1729742927&hash=item1c5c553d61:g:-agAAOSwYVlaDtK1

I bought one of these and it fills my batteries too full. Are they adjustable? How?

Many thanks.

[dmr]

I would be very tempted to get sealed for life/maintenance free batteries and replace them every year, every other year if you are lucky.

Its a fine dividing line between caring for expensive batteries, and using cheapo batteries as consumables, and ease of access and probability of acid spills are significant factors in making this decision.

If you are topping up cheapo batteries with poor access then you have the worst of both worlds.

..............Dave

[Ray T]

A selection here: http://www.boomsbeat.com/articles/166786/20161106/top-5-best-battery-water-filler-for-sale-2016.htm

To get into awkward places: 

[smileypete]

1 hour ago, Richard10002 said:

I bought one of these and it fills my batteries too full. Are they adjustable? How?

Many thanks.

What's the right level for your batts, and what level did it fill it to?

ISTR there was an issue with these that could lead to overfilling:

https://www.arc-components.com/0-149-50-1l-automatic-battery-filler-bottle-3226.html

Also it seems that the plastic ones must NOT be squeezed while filling the batts as this can lead to overfilling.

If a batt has lost electrolyte, is heavily sulphated or was underfilled when supplied, then filling to the 'correct' level can make the electrolyte weaker than it should ideally be.

When batts are newly supplied, it'd be a good idea to check and record the acid levels after a full charge, for future reference.

 

Anyway some info for the OP...

Battery FAQ section on maintenance:

    http://jgdarden.com/batteryfaq/carfaq3.htm

US Battery guide for topping up:

Trojan guide for topping up:

 

In summary the gist seems to be:

    Observe ALL safe handling precautions (important!)

    ONLY top up after a full charge.

    IF plates are exposed, add just enough water to cover the plates, then fully charge and recheck.

    Fill to between 1/8" and 3/8" below the bottom of the 'fill well', depending on manufacturers advice.

 

Some batteries have a bar or lip below the bottom of the fill well to show the fill level, and help fill to the correct level when using a filler bottle:

Edited December 17, 2017 by smileypete

[Dr Bob]

22 hours ago, Mike the Boilerman said:

Another idea, can you get your phone in there to take a photo looking down into the cell? Then post it on here. Someone is quite likely to recognise it.

Well that was a bit of a waste of time. Spent half an hour bent double trying to emmulate a 7 year old with a torch and the phone camera in the freezing cold ( it was actually a little better than that as we have a pram cover!). Got the perfect photo of the filler tube of the domestic bank. Got changed out of my acid stained clothes. Sat down with a hot coffee in front of the Ecofan/stove to review the photos and then realised the domestic batteries have a different fill tube to the engine start battery (the one with the slots). Too damn cold to go back and photo the start battery again, and anyway, I am only interested in how to fill the domestics.

The photo is below. I guess the hole that is visible is to vent any gas/liquid that comes out of the battery under use and is not anything to do with filling. What I have learnt from this thread is that I need an auto filling bottle - or make one myself - I now see how to do that, doesnt seem too difficult. Thanks to all who have contributed to a very dumb question and once again the forum has come up trumps.

There were no markings on the batteries other than the label you can see. No clue who makes them.

I did a search on the number on the label - 6110/14461108   and the search gave me an answer of a calculator yielding the answer of 42 *10 power -5. Arthur Dent would be proud of me.

[WotEver]

3 minutes ago, Dr Bob said:

I did a search on the number on the label - 6110/14461108   and the search gave me an answer of a calculator yielding the answer of 42 *10 power -5. Arthur Dent would be proud of me.

Well then, there’s your answer.

Now, what’s the question?

[Dr Bob]

4 minutes ago, WotEver said:

Well then, there’s your answer.

Now, what’s the question?

I then did a search of  6110  14461108 leaving the 'slash' out and it came up with

https://www.fullerbattery.co.uk/powerstation-6110-caravan-battery-110amp/

Looks like I have found my batteries. Only 200 cycles at 50% Dod? Sounds a bit low. Anyone got any comments on these? I think they are a year old now and I guess they have 90% of their capacity left (fully charged based on tail current - on shore power for 14 days) - and with an average specific gravity of 1.265 (checked only 3 cells) but not really sure of temperature - engine bay at 5°C but hydrometer started at room temp so estimating say 8-10°C - so SG 10% down on where it should be - so 90% original capacity?

[Rob-M]

20 hours ago, dmr said:

I would be very tempted to get sealed for life/maintenance free batteries and replace them every year, every other year if you are lucky.

Its a fine dividing line between caring for expensive batteries, and using cheapo batteries as consumables, and ease of access and probability of acid spills are significant factors in making this decision.

If you are topping up cheapo batteries with poor access then you have the worst of both worlds.

..............Dave

That is the approach I took as too difficult to get to the batteries, just going in to our 4th year with the first set purchased.

[Dr Bob]

2 minutes ago, Rob-M said:

That is the approach I took as too difficult to get to the batteries, just going in to our 4th year with the first set purchased.

That's what I will do next time when these give up.