Big lead acid single cell capacities

[NeilP]

Just got hold of some lead acid single cell units from a scrapped aircraft tug.

36 of them...2 volt each

XWBF17's

OK,so they are old...2006. so they are unlikely to have full capacity ..but I wondered what their original capacity should be.

http://www.espexbatteries.co.uk/brochures/Traction%202V%20DIN%20Standard%20-%20Normal%20Capacity.pdf

http://www.ceilbatterysystems.com/userfiles/file/CeilNXNORMALspecsheet_100923.pdf


The table linked to above say 80Ah Positive plate capacity, but the table entry for "Ah @C5 at 30 Deg C" shows 640 Ah ????what gives here?


I firstly picked them up for two reasons..scrap ;lead value and I can use the acid as a weedkiller to knock back ivy on the farm


But then I thought ..if there is enough life in these cells, then I can use them on my solar system in our camping / party / relaxation meadow, I have a little shed/ log cabin plus 200 watt of solar panel..but only maybe 40Ah of battery capacity.


I could rig up 12 of these as 6s2p and give me a waxing amount of capacity..even if they are only 50% of original...

Or am I better selling them off for scrap and just buying new lead acid cells designed for solar system ?

 

[Jon NCal]

Positive plate capacity probably means 80ah per positive plate and can infer your model has 8 plates.

Check the voltages and acid/water levels. You might want to add distilled water and charge and do a capacity test.

Looking at the photo of the batteries, it is a bit unsafe to have all the connectors uncovered and loose cables due to danger of accidentally short circuiting them.

 

[NeilP]

Yes, the plan was to check voltages and levels next.

Doing an accurate capacity test with only an iCharger will be a bit of a chalkange.

I do akso have a 20 amp 72 volt charger unit, that is dead a present, but maybe fixable.

Very little chance of shorts occuring,those wires don't move without force , and the exposed bolt tops are rubber.


Been years since I took a lead acid apart, yes of course, there is a bank of parallel wired plates. So yes 80*8= 640

 

[Jon NCal]

I once worked with a telephone tech that had some keys dangling from his belt. He was a bit alarmed when he leaned over the battery and his pants caught on fire.

I think the C5 capacity means 5 hour rate. Could use electric heaters to test?

 

[NeilP]

Yes, I guess C5 is not the same as 5C discharge. !!' I don't have any kit here to handle a 5*640 = 3200 amp discharge current!

First job needs to be pry off the rubber caps and remove the other bolts. It was about 3 hours work to remove the ones I havd done so far to strip the pack as far as it is.

 

[Punx0r]

I think C5 = C/5 = 0.2C

I would definitely use them instead of buying new ones if they're usable. They might be old, but probably of sturdy deep-cycle construction. They'll still be worth scrap value when they're properly dead

 

[Rassy]

Neil, I've had some good results using one of those pulse chargers, on both deep cycle marine batteries and SLA bricks. This is the one I use:

https://jet.com/product/product/1158328d75cc49b6843e2742bf8cfe4e?jcmp=pla:ggl:electronics_a1:electronics_accessories_power_battery_accessories_a1_other:na:na:na:na:na:2&code=PLA15&k_clickid=fdc4be52-5205-45ce-973c-2e18cb391d08&kpid=1158328d75cc49b6843e2742bf8cfe4e&gclid=Cj0KEQjwnMOwBRCAhp-ysqCwypkBEiQAeSy1-SbovexMmrERrGTUIbWYNSmiDu47WlRnDIOuxPFbPlUaAvvk8P8HAQ

It really can return well used batteries to like new performance, but it didn't work on every battery I tried it on.

 

[NeilP]

Thanks guys

I'll guess I'llhang on to them..and make a pack of 3840Ah ...that should do nicely ...my 2 x 40 Ah did not cut it for more than 6 hours...3840 Ah should see me good for a month of use

 

[NeilP]

Well a few years later and they are still running .
Kept charged by a measly 300 what of solar cells.

I checked the fluid levels in them last month.. I did them when I put them in...whenever this post was new..and only again this year,

Need about 30 litres of distilled water
No plates were uncovered but they definitely needed a drink!

Hell..2015 when if first put them in

 

[Punx0r]

:thumb:

Nice to see something well made with a long useful service life