Discover 2v 920ah opinions

[bigrockcandymountain]

I have a chance to pick up a 48v bank of 2v 920ah Discover OPzS batteries second hand.  They are about 6 years old, and were in a cabin, so likely not cycled as often as a primary residence. 

Being replaced as part of a remodel / expansion.

What do you guys think?  What are they worth?

[SparWeb]

45kWhr is going to be quite a load of lead to haul!

Maybe obvious: Check for swelling or signs of freezing if they were left discharged over winter.

Here's a set of Rolls batteries on Kijiji for comparison (about 1/2 the capacity of that giant Discover bank):
https://www.kijiji.ca/v-renovation-electrical/muskoka/rolls-deep-cycle-solar-batteries/1675480638

[bigrockcandymountain]

Well, I'm not sure it was a good idea, but here we go.  They were sitting for most of a year, and are all still showing 60% to 70% state of charge.  The tops looked quite corroded, but other than that they seem fine. 

If I get 6 years, for what I paid, I think I'm even with buying new rolls s550   They are 5 years old and a 20 year design life battery, so I'm hoping for more like 10 to 15 years out of them. 

I'm also in the process of adding 2.4kw solar, for a total of 5.4kw.  By the end of the week, we should be looking a lot better for power. 

Now to haul them into the basement.  I have lots of beer.  Anybody? 😁

[DamonHD]

I'll drink beer to your new storage lifetime!

Rgds

Damon

[bigrockcandymountain]

Batteries are in and mostly hooked up. I'll finish and hook up power today.  They sure look big beside the old L16 bank.  (Red)

They were overfilled with water when i got them. All the SG were pretty even, so I drained 2 cups exactly out of each cell.  Ill add it back in when the levels drop. 

Discover doesn't exactly list an absorb voltage for these.  The feeling i get is they run lower voltages than L16.  I'll start with 57.6v absorb and check gravity to get the target of 1.240

I'll be closing in a battery box over them right away and ventilating it to outside. They list 2.5kwh at 120h for capacity.  That means 60kwh storage.  This seems like way overkill but hey, hopefully i got lucky.

[SparWeb]

I see you're not superstitious about leaving LA batteries on a concrete floor.  Ah the funny old-wives tales I've heard since I started reading forums in RE.

In the pictures on the truck I can see through the case to the tops of the plates.  How much air space should there be?  Do you have a watering system planned?

Sorry I missed the call for helping hands.  Gimme more warning next time.  It's only a 7 hour drive, eh

[bigrockcandymountain]

Ya, no worries sparweb.  I'll get your help when they need to be hauled out.  Going down was easy....😁



The glowing line above max is the water level now.  I can't seem to get the S. G.  To 1.240 but i think that makes sense.  The lower line says 1.260 and the upper line 1.240,  so extrapolating, they should be 1.220 where they are filled to now.  I'm seeing a bit more than that so hopefully all is well.  I'll set the charge a bit high so they desulphate and use up the extra water. 

Now for the next project.  Making my gas stove into a hybrid. 

[SparWeb]

That plan sounds good!
I see the trend your pointing at, too.  It might take a while to evaporate off that much water, though...
This could be like your diversion load for a few weeks.

[Jackir]

Seems like a decent deal if they're in good shape. Check their condition and compare prices for similar used batteries to gauge their worth.

[kitestrings]

Oh wow, those look promising.  So, 2-volt cells with 4-terminals.  Is that just to allow for wiring.  It's one series-string of 24?  Or are there two cells in each case?  I bet they are heavy buggers.

[bigrockcandymountain]

I'm not exactly sure why 4 terminals.  Probably for flexibility wiring.  They are very geared toward telecom applications 8 think. 

They are 2v cells, all in series.  130lbs each.  I put rails on the stairs to roll a dolly down to get them in the basement.  It was fairly easy.  Going up will be different.  Gravity and all that.  Hopefully I'm 15 years older when that needs to be done. 

[XeonPony]

Awesome score, congrats!

[kitestrings]

So far so good I understand?