Lead Acid circulatory air pump

[solarman216]

Hi all I need a pump to circulate gas from the top of my batteries to the bottom in order to eliminate acid stratification during charging in order to shorten the charge time and lower the temperature, I have 12 x 2 volt cells about 600 mm deep, currently I need to over charge in order to promote gassing to adequately mix the electrolyte, a pump would reduce this by 20 to 30% so could be well worth it if I can find a pump to do the job, thinking along the lines of aquarium air pumps but know nothing about them, looked at battery guys but prices are stupid, thing is the air in needs to be from the cells and not from fresh, any ideas? Rick

[Lazy-Ferret]

Not sure I understand, does this mean you will basically pit a tube in the cell to the bottom, and then blow air in?

I know it's not exactly the same, but when I used to etch the PCB's at the university, we used a fish tank air pump to circulate the ferric chloride.

How much air will you need?

[jims-terrano]

One thing that struck me is what about sparks from a pump if recirculating the charging gases.

Advantage of an aquarium pump is they are electromagnetic that operate a diaphragm which should eliminate any risk of sparks.

Biggest problem would be feeding the gases into the pump and would the pump actually circulate enough volume.

What about a 12v tyre inflator as I think they tend to be a piston type compressor.

[Lazy-Ferret]

Most fish tank don't spark, they use a pair of electrical coils, to pull a solenoid connected to a pair of bellows back and forward. Main problem is, the bellows tend to work harden, and you have to replace them every year or so.

What you ideally want is one of the old Medcalf Hy-Flo pumps, beautiful bit of kit, they use a coil to induce an eddy current into an aluminium disk, that then revolves, and drives 2 crank shafts connected to little pistons.... all you have to do is put a drip of oil on them once a month or so. Only problem is, they fetch quite good money now, as they are collectors items. I had 2 for my fish tanks, spent almost as much time watching the pumps, as watching the fish... Other thing is, rather than the annoying buzzing the modern ones make, these do a relaxing chuff...

[solarman216]

Not sure I understand, does this mean you will basically pit a tube in the cell to the bottom, and then blow air in?

I know it's not exactly the same, but when I used to etch the PCB's at the university, we used a fish tank air pump to circulate the ferric chloride.

How much air will you need?

Not much air just enough to produce bubbles to stir the acid up, from what I have seen of fish tanks I might need a separate pump for each cell, plus it may be important to keep the gasses for each cell separate, Rick

[Lazy-Ferret]

Not much air just enough to produce bubbles to stir the acid up, from what I have seen of fish tanks I might need a separate pump for each cell, plus it may be important to keep the gasses for each cell separate, Rick

The main problem is, I can't think of any pumps that allow you to choose where the "in" air comes from. I forgot that when I mentioned the Medcalf one, as the pistons are made from brass, and I think the acid air would attack the piston. I guess it would have to be one with the Rubber bellows, and these can be got in a multitude of sizes.

Most of the pumps I have had over the years have an opening on the side or back about 1/2" across, with a foam filter pushed it, you would be able to make a converter that pushed into there fairly easily.

Does the drawn air from a battery have to be returned to the same battery, because if it does, then as you say, you would need a pump for each cell?

If not, then I think you would be fine for a larger fish tank pump to do 2 or 3 cells, especially if you fitted an air stone to each one. The only problem with the airstones is in water, over time they block up, and again, I am not sure what the acidic air would do to them.

[rayf3262]

A peristaltic pump like this may do?

https://www.amazon.co.uk/Yosoo-Peristaltic-Chemical-19-100ml-Analytical/dp/B017NFFLMG?ref_=fsclp_pl_dp_1

Here's how it operates:
https://en.m.wikipedia.org/wiki/Peristaltic_pump

[solarman216]

Thanks Ray, they look the business, not sure if I need one for each cell but guess I do to keep the acid contained to each, so 18 x 12 = 216 plus pipe and bits, dear but could be worth it in the long run, Rick

[rayf3262]

Ive seen some on eBay for under a fiver.

[rayf3262]

Here...
https://www.ebay.co.uk/itm/DC12V-24V-Dosing-Pump-Peristaltic-Tube-Head-For-Aquarium-Lab-Chemical-Analysis-G/143006958435?hash=item214be10363:m:mE0LG_k1NxY-wL6kwpW94rg

[solarman216]

Ive seen some on eBay for under a fiver.

Ace will have a hunt round, Rick

[solarman216]

Found some at £77 for 12, ordered and paid, thanks Ray, Rick

[rayf3262]

Sounds good.
I would think you would also have the option of circulating the electrolyte from bottom to top with these pumps?

[solarman216]

Yes precisely my thoughts as opposed to bubbling air but need to be careful that debris is not stired up as well, will be looking at manufactures data as well, Rick

[macabethiel]

Most fish tank don't spark, they use a pair of electrical coils, to pull a solenoid connected to a pair of bellows back and forward. Main problem is, the bellows tend to work harden, and you have to replace them every year or so.

What you ideally want is one of the old Medcalf Hy-Flo pumps, beautiful bit of kit, they use a coil to induce an eddy current into an aluminium disk, that then revolves, and drives 2 crank shafts connected to little pistons.... all you have to do is put a drip of oil on them once a month or so. Only problem is, they fetch quite good money now, as they are collectors items. I had 2 for my fish tanks, spent almost as much time watching the pumps, as watching the fish... Other thing is, rather than the annoying buzzing the modern ones make, these do a relaxing chuff...

I had one of the last Hy-Flo Pumps before they stopped production it was a double piston model it was mostly brass with a black plastic / ceramic cylinders. It was a work of art in itself watching the flywheel run. Sold it on e-bay about 10 years ago for more than it cost.

[Lazy-Ferret]

I had one of the last Hy-Flo Pumps before they stopped production it was a double piston model it was mostly brass with a black plastic / ceramic cylinders. It was a work of art in itself watching the flywheel run. Sold it on e-bay about 10 years ago for more than it cost.

I have 2 earlier ones, one has the double piston, with 2 outlets on each, and one is the single piston one. The good thing about them being earlier ones, is the whole piston and cylinder are brass. I got rid of my fish tank a few years back, but just can't bear to part with the pumps.

[macabethiel]

I have 2 earlier ones, one has the double piston, with 2 outlets on each, and one is the single piston one. The good thing about them being earlier ones, is the whole piston and cylinder are brass. I got rid of my fish tank a few years back, but just can't bear to part with the pumps.

It's a shame they were power hungry and lacked depth pressure. I was mesmerised as a nine year old child when a long gone store named Ratcliffes / Hutchinsons ? on Cockpit Hill in Derby had a pet section. They had one supplying the air to about 8 tanks.

About 30 years later I bought my own, I contacted the manufacturers for some spares many years later, they had a semi-retired employee who was in charge of the parts for Hy-Flo who worked out of a shed. Sadly when he fully retired they wound up the production & parts supply. One of my cylinders had a small crack in the wall (plastic type) and no parts were available. Still sold it with a declared fault as it did not seem to affect its function the bronze painted magnet housing was as new. As I recall the flywheel would get quite hot due to the inducted magnetic field.

[solarman216]

Got 12 of these little fellas, delivered yesterday, so now got to make up a mounting board, plumb and wire em up, Rick

[Wallace]

Is that 12 x 2v cell setup in a vehicle?

[solarman216]

Nah it weighs over half a tonne, Rick

[Wallace]

Nah it weighs over half a tonne, Rick

That's a fair old lump, is it for off grid solar power? I'm intrigued! :)

[solarman216]

That's a fair old lump, is it for off grid solar power? I'm intrigued! :)

Yes mate been off grid for over 12 years, this pump set up is for the newer bank about 2 years old but they are deep cells so need to gas lots to mix the electrolyte but in the interest of economy mixing it with little pumps should prove beneficial, the original bank now 10 years old and still going strong do not have so much of this problem as they are around half the height but larger foot print, Rick

[Wallace]

That's really cool. I have always fancied doing something similar for low voltage house lighting inspired by someone I met as a young lad. Have you ever heard of Captain Maurice Seddon? My Father and I bumped into him while looking at his BSA B33 parked up in Slough around 1980. This bike had an amazing setup for the electrically heated clothing he made and sold but also for cooking and tea making in the panniers and top box among other things while he rode. The heated clothing development was initially for relief from the Reynaud's disease he suffered with, to keep warm at home he had submarine batteries and would plug himself in from room to room. A fascinating chap who sadly died in 2014.

[solarman216]

No not heard of him but sounds like he was an interesting guy, but so am I as you will see as we converse, we have good solar here for electric and hot water, also had a 10 ft overshot water wheel but the water dried up, not completely but wheel no longer turns, our drinking water is drawn from a spring, pumped into an 8000 ltr holding tank after being filtered, best water you will ever get, nearest neighbour is more than 500 mts away, we love it, Rick

[Wallace]

500m, I'm jealous already! :D

[Banshee]

No not heard of him but sounds like he was an interesting guy, but so am I as you will see as we converse, we have good solar here for electric and hot water, also had a 10 ft overshot water wheel but the water dried up, not completely but wheel no longer turns, our drinking water is drawn from a spring, pumped into an 8000 ltr holding tank after being filtered, best water you will ever get, nearest neighbour is more than 500 mts away, we love it, Rick

I need some of that water Rick!!!!!

[solarman216]

Finally got the pumps working today, results look good, after about 3 hours charging the readings were 1140, 10 mins after starting the pumps they were 1180 so yes a result, i now need to make up a 12 power supply capable of delivering a good 4 amps and put it on a timer as do not need to run the pumps continuously, I chose to draw acid from 50mm of the bottom of the cells and return it to the top rather than pump air into the bottom as I did not feel the acid would be mixed very evenly, time will tell if any of the tubing suffers from the acid, this is how the set up looks, I can tidy the tubing once it has all proven itself as I need to put an insulating cover over the whole lot as these batteries are designed to run at 30 deg C, lower temps mean less capacity, Rick

[macabethiel]

Yes mate been off grid for over 12 years, this pump set up is for the newer bank about 2 years old but they are deep cells so need to gas lots to mix the electrolyte but in the interest of economy mixing it with little pumps should prove beneficial, the original bank now 10 years old and still going strong do not have so much of this problem as they are around half the height but larger foot print, Rick

Off Grid & your own water supply that sounds like a recipe for low overheads & cheap rates I guess.

What do you use for winter heating then wood, coal or Calor ?

[Blocky10]

Off Grid & your own water supply that sounds like a recipe for low overheads & cheap rates I guess.

What do you use for winter heating then wood, coal or Calor ?

Scotch and body heat at a guess :lol

[solarman216]

Off Grid & your own water supply that sounds like a recipe for low overheads & cheap rates I guess.

What do you use for winter heating then wood, coal or Calor ?

Low overheads yes, rates no and they do not even collect my rubbish, and all the other things they are supposed to supply, I am sick of them, as for heat we have a wood burner and plenty of wood, solar for hot water and solar PV to top up batteries when the sun shines, this time of year is the most expensive as gen run time is at its worst for 4 reasons (1) little or no sun, (2) most times need tumble drier to dry clothes, (3) lights need to be on longer, (4) low temperatures mean batteries are not at their best, but would not change it for the world, Rick

[solarman216]

Scotch and body heat at a guess :lol

Surprisingly as we are so well insulated body heat makes a good contribution to the inside temperature, scotch no only effects my heat, Rick

[jims-terrano]

So envious of your setup Rick. Problem is that if you tried to be like or as near like this in most houses people would complain simply because it’s different and people don’t like different. That’s what your 500m does for you.

[solarman216]

Yep we are isolated and love it, if I wanted (god forbid) to go out now and start my chain saw to cut up some logs there is no one to complain, Rick

[Wallace]

That’s a cool setup, do you not have any wind turbines?

[solarman216]

Unfortunately very little wind here so no not a realistic project, Rick

[solarman216]

Sadly the acid pump idea has failed, the pumps could not cope with the pressures and most have given up, I might try and resurrect them to pump air which I think they will cope with, but will be less efficient, Rick

[jonny]

That sounds like a great life and something I aspire to. We have solar panels but only enough to heat the water, and a log burner for heat. My wife is a lecturer at a countryside collage and the arb and forestry section keeps us topped up with logs, plus I live right by a forest which is great for wind fall or if the have been felling. I have been looking into steam powered generators. They look quite good and pretty silent, which is what we need as we aren't quite as lucky as you with the neighbour situation. But, we are in quite a windy area though so a wind turbine is something we are mulling over.