Blind battery refill

[lifer]

I had to relocate my battery bank on a low height shelf. Everything was perfect until I had to do the regular maintenance (watering/level check).

As there's limited clearance (30-40 cm), it's very dificult to look inside each cell. Moreover, the electrolyte is very clear thus I cann't even see the actual level.

I've tried to use a mirror and a flash light with no success. I might use a piece of paper and push it down through the filling hole till it reach the top of the lead plates then I would check the wet area (just like a regular engine oil check).

Anyway, I have to repeat this operation many times for each cell (after adding a small amount of water) to verify the current electrolyte level. I'm also afraid of contaminating the electrolyte due to such a blind manoeuvres.

Is there any smarter procedure for a situation like this?

[mab]

a battery hygrometer with a flexible tube? (mine has a 3" rubber tube) - if you can't suck electrolyte up without air you need to add more water, sort of thing.

[lifer]

I'm afraid of adding too much water. I need a more accurate procedure I believe.

[petect]

There are a couple of companies that make systems like this, mostly for bass boats that have 3 - 4 batteries stuffed into tight places. There are similar for golf carts.

https://flow-rite.com/battery-watering/marine-rv/qwik-fill

There are some vids on youtube for commercial systems. They might give enough info on how they work for you to make your own.
Pete

[thirteen]

Drill a hole above each cell  big enough to see its needs  and then cover it with a sheet of plastic or small piece of plywood. 13

[lifer]

Drill a hole above each cell  big enough to see its needs  and then cover it with a sheet of plastic or small piece of plywood. 13

Unfortunatelly, I have batteries on the shelf too hence I could not drill a hole.

There are a couple of companies that make systems like this, mostly for bass boats that have 3 - 4 batteries stuffed into tight places. There are similar for golf carts.

Very interesting watering systems, indeed. As far as I read, you have to replace the original lids. Does it supposed to have a standard dimension? I have two different battery models and the caps look different, too.

Btw, I was concerning about the maximum electrolyte level as I can't see clearly the top of the battery plates. But I found this image:



So do I have to fill it to the bottom of that vent tube? Because I could see it quite well hence I could easily add water to that level.

==

Later edit: Now I found this one:



Which one is correct?

[David HK]

I worked all this out on this website years ago.

Ghurd helped me. I have just tried researching and cannot trace anything. I have also checked my old PCB Express files and cannot find the circuit diagram.

From memory, I recall a nylon plug with a stainless steel pipe for injecting the electrolyte into a cell. Also, on this plug, were contacts to illuminate a green LED when it made contact with the electrolyte at the required level. It was a long time ago. I could only make it work on 5 out of 6 cells on a 12 volt battery. Never did clear up the mystery of the 6th cell not want to play with the LED.

Can someone wake up Ghurd - he may remember the case.

I will try to keep searching.

Dave

[lifer]

According to a battery manufacturer (HAWKER), there have to be an empty space (3 mm) between the electrolyte maximum level and the vent tube bottom edge.

[David HK]

Found it - try this URL


http://www.fieldlines.com/index.php/topic,141293.msg965275.html#msg965275

Dave

[David HK]

Just found the circuit diagram.

Its a bmp file  - not sure if it will show,

Dave

[lifer]

From memory, I recall a nylon plug with a stainless steel pipe for injecting the electrolyte into a cell. Also, on this plug, were contacts to illuminate a green LED when it made contact with the electrolyte at the required level.

Thanks, Dave! I thought about an electronic circuit too. I was not sure what type of electrode material to use for contacts to avoid corrosion. I though about copper but maybe lead it's a better option.

The electronic circuit should be pretty simple as it only have to detect a variable resistance (an usual opamp might be enough). Thanks for the tip!

[David HK]

I am not sure if my battery nylon plug tester survives. I will need to check my scrap box tomorrow - Saturday and will post if I find anything. This was about 6 years ago.

From memory I preset the water level depth probe to suit the battery - it was not loose handheld. I  placed it on top of the screw threaded hole for the cell plug and if the LED did not light - then I just squeezed in electrolyte until the LED glowed (illuminated).

I also did not blow myself up!

Dave

[lifer]

(sorry, we are posting simultaneously)

Thanks for the link! That could solve my problem, indeed. But like @Flux has suggested in that thread (reply #63) I was thinking of using two electrodes and an opamp to check for conductivity. A portable circuit (using a small battery) could be better though.

[David HK]

Lifer you may receive more accurate advice from other forumites, all I did was use the battery (to be watered) itself for the power supply.

Experimentation may well produce something that solves your problem.

Good luck.

Dave

[lifer]

Dave,

I think that the electrolyte in first cell (the one containing the minus pole) has the same electric potential as the negative plate thus you've got zero volts when reading the electrolyte voltage. For that matter, the second cell's electrolyte has an electric potential of 2 V and so on.

The circuit you've posted could be adapted to work with the first cell (you just need to change the reference).

[hiker]

What about using baby oil to top off your cells...slows down evaporation ...I belive their were a few posts awhile back..about using baby oil ??

[David HK]

Found some old photographs. Readers should be able to understand that the breadoard circuit follows the above posted schematic.

Negative and positive battery connections are obvious.

The probe depth can be adjusted up and down by pushing through the nylon washer.

What is not shown is the stainless steel pipe through the nylon which, in turn, connects to the electrolyte pipe.

Cannot find any trace of the original nylon unit.

Dave

[thirteen]

rebuild for a roll out shelf with support legs or removal  . 13

[lifer]

rebuild for a roll out shelf with support legs or removal  . 13

Yes, it would have been better that way. Anyway, I figured a way to make it quicker.

As I have better access to first cells, I've measured the quantity of water needed to complete the electrolyte level then I blindly poured the same quantity of water in every other cells.

After that, I further played with a mirror and a flash light to check the results: everything went just fine.

For the next maintenance visit, I'll try to make a circuit as above or to build an automatic watering system. Thanks everyone for your kind support.

[David HK]

I finally found the sensor end of my battery refiller. Please note the plastic disc also contains a 3mm diameter breather hole.

Dave

[XeonPony]

I recommend the flow rite system, it costs a bit but makes life stupid easy, I built my bank into a tight spot as well, but for me filling is just hooking up distilled water and pump till there is solid back pressure!

It takes all the gues work out and ensures all cells are equal.

[Norm]

I worked all this out on this website years ago.

Ghurd helped me. I have just tried researching and cannot trace anything. I have also checked my old PCB Express files and cannot find the circuit diagram.

From memory, I recall a nylon plug with a stainless steel pipe for injecting the electrolyte into a cell. Also, on this plug, were contacts to illuminate a green LED when it made contact with the electrolyte at the required level. It was a long time ago. I could only make it work on 5 out of 6 cells on a 12 volt battery. Never did clear up the mystery of the 6th cell not want to play with the LED.

Can someone wake up Ghurd - he may remember the case.

I will try to keep searching.

Dave

OK I tried to wake him up but he may be mean and grouchy ?
Norm.

[ghurd]

Somebody make coffee.

David's didn't work on one cell from not enough voltage.
I suppose the circuit could be build "backwards" for that cell. Don't know why we didn't think of it at the time.

For something not self powered, could use Sir Flux's idea. If so I'd use one of the new super extra ultra low power op amps. 4 X AAAs would last a very long time.
G-