Author Topic: Wet lead acid batteries - electrolyte level - how to observe  (Read 24043 times)

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David HK

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Re: Wet lead acid batteries - electrolyte level - how to observe
« Reply #33 on: May 04, 2010, 10:03:22 PM »
Dan G and ULR's above post.

Has this got anything to do with the current thread?

I am quite happy to replace the stainless steel probe with a lead one, but I am not in the game for plutonium and iridium.


David HK

DanG

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Re: Wet lead acid batteries - electrolyte level - how to observe
« Reply #34 on: May 05, 2010, 02:47:17 AM »
Oops. FLA, thanks (!). I see now water saver caps use low purity catalyst sponge or mesh to recombine H and O2, and a definite danger exists with high alloy platinum. I'd thought using a noble element gave zero chance of poisoning the warm acid, my original thought was suggest cutting up a maple leaf or a Krugerrand or Panda 999 fine gold coin... : )

DHK - Tungsten is equally resistant (and cheapish) and will survive better if you are manually polling every cell and storing the unit inbetween uses. For durability maybe look into a nylon triangle or cone with only a nub of metal showing?

Ungrounded Lightning Rod

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Re: Wet lead acid batteries - electrolyte level - how to observe
« Reply #35 on: May 10, 2010, 03:36:19 PM »
DHK - Tungsten is equally resistant (and cheapish) and will survive better if you are manually polling every cell and storing the unit inbetween uses. For durability maybe look into a nylon triangle or cone with only a nub of metal showing?

Note that you're passing current through the metal.  So the issue isn't solubility but electrolytic corrosion.  (If it were just solubility you wouldn't be able to electroplate gold...)

DanG

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Re: Wet lead acid batteries - electrolyte level - how to observe
« Reply #36 on: May 10, 2010, 05:40:47 PM »
Better survivability of tungsten mentioned as a mechanical property.  No one should want to attempt extracting a fatigued ribbon of lead from between plates.

chainsaw

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Re: Wet lead acid batteries - electrolyte level - how to observe
« Reply #37 on: May 11, 2010, 08:01:21 AM »
I have 12- 6 volt batteries ( 36 cells to water and maintain). After a few tedious ordeals of filling, spilling, with your face being over the batteries I sought a better less time consuming way to maintain this bank. I went with a BFS system, it now takes less then 2 minutes to fill all cells to the same level. The new battery caps have a VISIBLE indicator to observe your fluid level and also an access  for hydrometer or a temp probe. This single point watering has made this unpleasant chore a non-event.

David HK

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Re: Wet lead acid batteries - electrolyte level - how to observe
« Reply #38 on: May 12, 2010, 11:09:40 PM »
At long last i am now able to show you the revised design for my battery cell electrolyte tester built from Ghurd's circuit and now incorporating a nozzle so that the electrolyte can be brought up to the probe sensor level via a pipe connected to a bottle.

Would all viewers please note that I am fully aware of commercial products that can do the same job, but the whole purpose of the article is to highlight what most amateurs can do using limited resources. Quite where I would obtain tungsten, iridium or platinum for use as an electrode is beyond me.

I should be grateful if everybody would note that the test sensor is for occasional use only and will NOT be mass produced to permanently equip each battery cell.

Please note that the dimensions between the test pin and the electrolyte filling nozzle vary according to the diameter of the battery cell screw-in plug.




TomW

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Re: Wet lead acid batteries - electrolyte level - how to observe
« Reply #39 on: May 13, 2010, 03:24:34 PM »
David;

This little project has progressed nicely!

Looks good.

On a side note:

The new software has really improved how stories flow and continue.

On Sc00p this thread would have likely fizzled after 10 or 12 posts. This is #39 on this thread.

Thanks for the share and sorry for the comment drift.

Tom

Ungrounded Lightning Rod

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Re: Wet lead acid batteries - electrolyte level - how to observe
« Reply #40 on: May 13, 2010, 07:23:17 PM »
David;

This little project has progressed nicely!

Looks good.

On a side note:

The new software has really improved how stories flow and continue.

On Sc00p this thread would have likely fizzled after 10 or 12 posts. This is #39 on this thread.

Thanks for the share and sorry for the comment drift.

Tom

Downside:  New software makes it harder to track who is being replied to and doesn't have a "show me replies to MY post" feature.  That means to hold a conversation I have to look at every item I've ever responded to that is still live.  B-b

Granted with Scoop sometimes people did new responses rather than followups, so I had to do that kind of  "Anything new in any item I posted to" check occasionally to be sure they didn't get lost.  But I could save that for when I had more time to respond while going straight to the items where somebody had a question for me (and knew how to work the board) when time was tight.

DamonHD

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Re: Wet lead acid batteries - electrolyte level - how to observe
« Reply #41 on: May 14, 2010, 01:34:16 PM »
The second link down on the page for me is a "show replies to my post", and I'm using right now...

http://fieldlines.com/board/index.php?action=unreadreplies

What's more annoying for me is the inability to bookmark my own diary threads to add to them, and other key pearls of wisdom, but maybe I'll work out a way soon!

Rgds

Damon
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TomW

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Re: Wet lead acid batteries - electrolyte level - how to observe
« Reply #42 on: May 14, 2010, 01:55:23 PM »
The second link down on the page for me is a "show replies to my post", and I'm using right now...

http://fieldlines.com/board/index.php?action=unreadreplies

What's more annoying for me is the inability to bookmark my own diary threads to add to them, and other key pearls of wisdom, but maybe I'll work out a way soon!

Rgds

Damon

Damon;

Yeah a lot of the complaints are folks that just never checked very far into what is actually available as standard links on the pages. I posted the users guide link many times but here it is again.

http://docs.simplemachines.org/index.php

About halfway down on the left panel is a link for "users"

Folks really should inform themselves before saying "It doesn't do X" because it probably does.

Just the facts as I see them.

I do not miss customer support work at all. Nobody reads manuals or the FAQs.

Tom

DamonHD

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Re: Wet lead acid batteries - electrolyte level - how to observe
« Reply #43 on: May 14, 2010, 03:22:26 PM »
Hey, once or twice in my ISP days I actually fired customers who couldn't be bothered to read the manuals we'd sweated over at vast effort and supplied free...  I liked that part of customer support because it saved me and my support staff lots of money and trouble.  %-P

But in this case there are lots of distractions on the site and the different themes add some confusion, so I'm sure that I'm missing out on things that I want to do!

Rgds

Damon
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Ungrounded Lightning Rod

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Re: Wet lead acid batteries - electrolyte level - how to observe
« Reply #44 on: May 14, 2010, 04:44:19 PM »
The second link down on the page for me is a "show replies to my post", and I'm using right now...

Already aware of it.

Problem with that is it shows me anything I've ever responded to which has since been commented on, regardless of whether the comment is a response to me or not.  When I'm pressed for time I only want to see the people who responded to ME, and skip items where they're responding to somebody else.

David HK

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Re: Wet lead acid batteries - electrolyte level - how to observe
« Reply #45 on: May 14, 2010, 07:48:32 PM »
I've got a problem.

For those that have been following this topic from page one, everyone will note that I had a problem with Ghurd's first circuit which led to a revision and slight change in circuit components. I tested that on a motorcycle battery and sure enough the LED switched off when the probe touched the electrolyte in all six cells. I then put the kit away and waited for modifications to the probe holder so that it could incorporate an electrolyte topping up nozzle.

Yesterday I decided to test the whole apparatus on some 12 volt motor vehicle batteries that are in good condition and 60 - 70 AH.

The first battery test went as planned and starting with the cell at the positive post the LED extinguished each time until I came to the sixth cell where the LED failed to go out. Thinking it was low on electrolyte I filled up the sixth cell so that it was completely flooded and it was only then that I realised that the problem existed.

A test on the second battery confirmed the same result - the LED will not extinguish when testing the cell housing the negative post.

Two other observations arising from the test are:- provide a vent hole in the nylon disc holding the probe and wear protective gloves.

Over to you Ghurd.

ghurd

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Re: Wet lead acid batteries - electrolyte level - how to observe
« Reply #46 on: May 14, 2010, 10:09:45 PM »
This worked before, but not now?
Is it the same problem we started with?

Change the 270K to around 500K.
If that does not work, try around 750K.
(too high a value may not work either)
www.ghurd.info<<<-----Information on my Controller

David HK

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Re: Wet lead acid batteries - electrolyte level - how to observe
« Reply #47 on: May 15, 2010, 01:59:57 AM »
Ghurd,

Yes its the original problem. I changed the 270K to 560K and still experience the same problem - The LED will not extinguish on the sixth cell containing the negative battery post.

I wonder how the professional bits of kit work?

Regards,

Dave


TomW

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Re: Wet lead acid batteries - electrolyte level - how to observe
« Reply #48 on: May 15, 2010, 08:11:00 AM »
Ghurd,

Yes its the original problem. I changed the 270K to 560K and still experience the same problem - The LED will not extinguish on the sixth cell containing the negative battery post.

I wonder how the professional bits of kit work?

Regards,

Dave



Dave;

Just a wild thought:

Maybe they use some electrickery to sense the level "both ways". As in not just in reference to the - post potential but to the +?

If that makes sense?

Not sure "how" but that is the approach I would use in a block diagram of obtaining the desired result with this result while on that cell.

Good Luck with it.

Tom

ghurd

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Re: Wet lead acid batteries - electrolyte level - how to observe
« Reply #49 on: May 15, 2010, 09:37:46 AM »
Maybe change the 10K base resistor to 5K.

What part number and company is the transistor?

I can not see why it does not work, so it is hard to guess what to change.
G-
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David HK

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Re: Wet lead acid batteries - electrolyte level - how to observe
« Reply #50 on: May 15, 2010, 07:28:06 PM »
Glenn,

I changed the resistor to 3K3 as I do not have a 5K handy. Result is the same - LED will not extinguish in the sixth cell with negative post. Otherwise, the LED will go out in all other cells.

The transistor is KSP 2222A  J12  (data sheet here - http://www.datasheetcatalog.org/datasheet/fairchild/KSP2222A.pdf  )

Dave

David HK

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Re: Wet lead acid batteries - electrolyte level - how to observe
« Reply #51 on: May 15, 2010, 07:57:10 PM »
Apparent success! ;D ;D

I took some dry paper and marked out two lengths - 28mm and 34 mm which are the depths from the top edge of the cells on two different batteries down to the electrolyte level in each one.

I am much embarrassed to reprot that in each case the paper showed no contact (wetting) with electrolyte in each sixth cell - no wonder we have ended up scratching our heads. I then filled up with electrolyte until I could see a wetting of the test paper.

I then checked using the electronic circuit which now has 3K3 and 560K substitutes the the 10K and 270K respectively and in both sixth cells on each battery the LED remained extinguished whilst the probe touched the electrolyte.

I now do a paper wetting check on all the cells of each battery and fill with electrolyte to the required maximum level. After this I shall then do an electronics check and all being well I should see 100% success. This will also confirm that the circuit works.

Its quite difficult to gauge liquid levels when looking down on them in poor light.

Apoligies for wasting time, but i suppose we have all learnt something.

Regards,

Dave

David HK

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Re: Wet lead acid batteries - electrolyte level - how to observe
« Reply #52 on: May 15, 2010, 09:11:59 PM »
 ??? ???  It appears i am not quite there yet.

I have done the wet paper test on all the cells for two 12 volt batteries and know for sure that the electrolyte is up to the recommended maximum level recommended for each battery.

I then did the usual electronic cell test starting at the Positive post cell and for five out of the six cells the LED extinguished without fail when it touches the electrolyte.

The sixth cell containing the Negative post is intermittent. When it works it works and when it doesn't it doesn't. I measured the voltage between the electrolyte probe and the Negative post on the sixth cell and it reads 1.5 volts although the DMM goes into a slow counting mode.

Has anyone else built Ghurd's circuit? If yes, what is your experience?

David in HK

By the way has Canada defrosted yet?

David HK

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Re: Wet lead acid batteries - electrolyte level - how to observe
« Reply #53 on: May 15, 2010, 10:16:56 PM »
Another interesting observation.

Dip the probe into the sixth cell (battery negative post) and the LED fails to dim. Remove the test probe, disconnect the Negative supply wire from the circuit.

Reconnect battery negative wire to circuit, insert test probe into the sixth cell and BINGO the LED goes out and will continue to go out for more than 10 test probe inserts.

May be useful for the experts.

Regards,

Dave

ghurd

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Re: Wet lead acid batteries - electrolyte level - how to observe
« Reply #54 on: May 16, 2010, 08:10:17 AM »
The 2N2222 should be saturated with 0.6V to 1.2V on the Base (the probe), and the LED should go out.

I have no idea why it does not.

Maybe- Add another 270K resistor (or whatever value you are using now) to the 2N7000 Gate, but connect it to negative.

G-
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DamonHD

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Re: Wet lead acid batteries - electrolyte level - how to observe
« Reply #55 on: May 16, 2010, 09:43:01 AM »
OK, that's a tighter definition than I've needed so far!

Rgds

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David HK

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Re: Wet lead acid batteries - electrolyte level - how to observe
« Reply #56 on: May 17, 2010, 06:58:37 PM »
I have been doing some research and came across an interesting article at this URL   --   

http://www.rvtechstop.com/articles/batmon.pdf

Firstly note that the transistor shown in the sketch is a 2222A.

Secondly read the text sandwiched between Figure I and Figure II. In particular note "On a 12 volt battery, it should not be placed in the cell that contains the negative post, OR, in an adjacent cell because 6 volts do not appear until the third cell. The first half of the sentence is interesting and has obviously been written for a reason.

Readers will note that all my problems arise from the cell containing the negative post.

I have had a thought. If i connect the test circuit to a separate 12 volt battery to supply the circuit power, and then connect the ground of the battery under test to the ground of the battery supplying circuit power - what would happen when I tested the cell with the negative post?

I am determined not to give up on this useful and very desirable piece of test gear.

David in HK

David HK

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Re: Wet lead acid batteries - electrolyte level - how to observe
« Reply #57 on: May 19, 2010, 06:04:07 PM »
I have sent a begging e-mail to a well known battery manufacturing company explaining the problem in detail in the hope that  experts can offer some comments.




David HK

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Re: Wet lead acid batteries - electrolyte level - how to observe
« Reply #58 on: May 20, 2010, 07:35:22 PM »
The reply from the local agent for well known deep cycle batteries was out of kilter with the thrust of my enquiry.

Anyway i am pressing on.

US Patent for 'Blinky" battery electrolyte level detector. The second page is at this URL http://www.wikipatents.com/US-Patent-5936382/battery-electrolyte-level-monitor/Page-2

Am I correct in assuming that the LED connects to a simple lead probe? The resistor appears to be in series with the LED legs - any guess on the resistor value?

This device seems to be a one-off sensor for a whole battery rather than one that is dipped in each consecutive cell. I wonder how it would respond in the sixth cell containing the negative post?

Looking for to any comments

David HK

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Re: Wet lead acid batteries - electrolyte level - how to observe
« Reply #59 on: May 20, 2010, 08:19:51 PM »
http://www.vandapower.com/PDF/Blinky%20EN%20v.1008.pdf

Above is the URL for the Blinky. After reading the text it would seem that the LED can emit either Red or Green. It also requires 4 volts DC to operate, which would mean that it coult not operate when dipped in the cell containing the Negative electrode.

Getting there slowly.

David HK

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Re: Wet lead acid batteries - electrolyte level - how to observe
« Reply #60 on: May 21, 2010, 06:33:08 PM »
I am waiting for a reply from an American company that speciallises in various products associated with batteries.

I have spent many hours going over the Internet and dragging out what I can in the way of information about the determination of the high and low level of electrolyte liquid.

I have also reached some conclusions which I will write up and post sometime in the next 10 days.

David HK

David HK

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Re: Wet lead acid batteries - electrolyte level - how to observe
« Reply #61 on: May 22, 2010, 07:48:16 PM »
The particular topic has recorded over 3,000 viewings so the subject must be of considerable interest to people.  For those that have not read this thread go to page one.

For those that have been following my reports you will al note that Ghurd's modified circuit works fine on all cells one to five counting from the Positive battery post. The sixth cell containing the Negative post seems to be a gremlin and the LED fails to extinguish when the probe is inserted. Whether this is an electro chemical problem or not is beyond my knowledge.

Ghurd's circuit takes its power from the battery under test and uses a single probe. I have trawled the Internet for hours looking for ‘water' level test circuits and there are plenty of them BUT most involve two wire probes and nothing would induce me to insert two wires into a battery cell. I err on the side of caution and am not keen on making myself as test guinea pig for a battery explosion.

In industrial and commercial operations there are indeed very nice LED sensors that are bi-polar but these are not inserted in each cell. This quote from a man in Australia sums things up quite well  - “In industrial applications, we put the electrolyte sensor on the middle cell as this cell gets the hottest and has the greatest fluid loss. In the Industrial division we do not put electrolyte sensors on Block batteries”. I do not know what Block batteries are but it makes little difference to the comment. What this means is that a Red LED showing on the sensor cell is a signal to re-water and check all the other cells at the same time.

Trying to find anything on the Internet that can establish the electrolyte level (not the SG level) is like looking for a needle in a haystack and the only ‘ancient' guidance I can find lies on the Powerstream website at this URL  http://www.powerstream.com/1922/battery_1922_WITTE/batteryfiles/chapter09.htm

Basically the test machine is a glass pipette and if it is suitably graduated to suit the battery under test it should work.

There is another way which anyone can replicate at zero cost. Unscrew and remove the cap from any cell. Place a clean piece of wood over the cap hole so that it extends over the side of the battery where the maximum and minimum levels are marked. Measure the heights and then write the details onto the side of the battery for ready reference. Obtain some clean white paper, scissors, and a pen and ruler. Mark a line from one edge of the paper to – say – the maximum level depth (in my case 26 and 34 mm on two separate batteries). Then cut the paper into strips of – say – 10cm by 1cm. If the battery is at floor level this test is very awkward, but if it's more than 600mm above ground level its much easier. Rip off one piece of test paper and insert it in the cell until your eye sees the line at the top edge of the cell plug hole. Remove the paper and see if the bottom edge has touched the acid – I'm sure most of you have seen what happens when dry paper touches a liquid so I will not explain further. Anyway, if the paper is dry – add electrolyte and keep checking with same test paper until a wetness can be seen on the bottom tip. Then carry on to the next cell. Simple.

When searching the Internet I came across countless web sites which mention “check the electrolyte level” but they make no mention of the methodology of doing it. It's quite laughable that even premier battery manufacturers follow this practice and I quote from one of them - “Remove the vent caps and place them upside down so that dirt does not get on the underside of the cap, or, for the --------  series batteries, simply flip open the cap. Check the electrolyte level”. That's all there is from a very respectable battery manufacturer “Check the electrolyte level”. Nothing about how to do it.

What next? Ghurd's circuit works well, but is it worth the effort? Or, should I just stick with the paper method? The wet lead acid battery must have been around for about 150 years now, and much must have been written about the subject, but where is all the information?

I hope I have saved all readers some time and brought everyone up-to-date on the subject as I know it to be in May 2010. If I have written anything that is wrong or unclear, please make a comment.

I will follow up with the result of an enquiry with a USA sensor maker when I receive a reply.

David in HK




David HK

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Re: Wet lead acid batteries - electrolyte level - how to observe
« Reply #62 on: May 22, 2010, 08:58:19 PM »
I forgot to include in the Reply above that the article is the net result of the power of the Internet and the Google search engine. I really have not made much progess at all.

 

Flux

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Re: Wet lead acid batteries - electrolyte level - how to observe
« Reply #63 on: May 23, 2010, 04:45:04 AM »
I have not been following this, I never realised it was an issue.

For the first 100 plus years of the lead acid battery they were in glass jars and you could just see the acid level.

For later construction I have never been in a position where you couldn't see the electrolyte level with the cap removed and most manufacturers provide a sort of ledge to give you a reference to look at.

I presume you have yours in a position where you can't look into them. Certainly you can use an electrical probe but I think I would use 2 wires and power it from a separate little circuit using a battery and a high impedance op amp circuit, there would be no current to cause a fire. Using the battery itself to supply the circuit should be possible but you may get the strange effects you mention unless you use a very clever circuit.

How about a stop on the spout of a hydrometer at electrolyte level. Insert and squeeze, if you get liquid the level is ok, if you get liquid and air it is at that level. if you get no liquid then it needs topping up.

Flux

David HK

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Re: Wet lead acid batteries - electrolyte level - how to observe
« Reply #64 on: May 24, 2010, 05:55:15 PM »
The reply from a USA manufacturer of electrolyte sensor levels does not add anything new to what has been written already.

Unless anyone comes up with any new ideas, I do not intend to research further or write more for the time being.

I hope you find the article interesting.

David in HK

Ungrounded Lightning Rod

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Re: Wet lead acid batteries - electrolyte level - how to observe
« Reply #65 on: May 24, 2010, 06:19:46 PM »
For later (than glass-cased) construction I have never been in a position where you couldn't see the electrolyte level with the cap removed and most manufacturers provide a sort of ledge to give you a reference to look at.

The deep-cycle cells I've seen lately seem to have two items related to this:

 - The passage below the fill hole has a "pipe" that extends downward partway to the cells, with a pair of slots in its side.  I'm presuming the bottom of this is the "full" level (fill it until the level touches the bottom of the pipe) and the slots are to let gas escape when the cell is full without blowing the electrolyte out the fill cap.

 - Some recent batteries seem to have a medallion mounted just above the plates with a single letter embossed into it.  I'm presuming this there to reflect light a bit to make observation easier and represents the lowest safe level for the electrolyte.

Quote
I presume you have yours in a position where you can't look into them.

Seems to me that a mirror would help in such a situation.  Or two as a periscope.  Add an LED to illuminate the cell, a hose for filling, and some ridges to line it up with the fill hole and you have a handy-dandy tool requiring now electrical contact with the water to do the fill.

Alternatively:  Mount the hose so, when the tool is seated, it reaches the fill line.  Include a bottle of distilled water and a hose clamp.  (Stick a glass eyedropper in the end of the hose to have an acid-happy tip with a narrow opening.)  Open the clamp and, like a rodent watering bottle, air bubbles will come up the hose and let the water fall into the cell until the level covers the end of the filler with a tad to spare.  Be sure to close the hose clamp before moving on, and use the observation mirror to check the next cell before opening the clamp, in case you got some bubbles into the hose and hit a nearly-full cell.

Quote
How about a stop on the spout of a hydrometer at electrolyte level. Insert and squeeze, if you get liquid the level is ok, if you get liquid and air it is at that level. if you get no liquid then it needs topping up.

I'd use a separate (small and cheap) hydrometer for that test.  Adding water temporarily stratifies the cell so you don't want to test the specific gravity just afterward.  The stop would make it impossible to do the test except just after you topped off the cell.  So you want a separate device for the level test.