2 X T105's: some Batt advice requested.

[steak2k1]

OK:  Here's the deal. I have had these units for over two years and have never really pulled a significant load on them such that they would be down to 20/25% DOD.

They have however sat in my garage over the winter periods (8 months) and I preiodically charged them up with a trickle charger running at 2 Amp output. They normally reside on a bumper at the rear of the tent trailer I use them on.

I have since learned from his site and a great FAQ on Batts, that float charging is the way to go.

So I have the charger and I also have a spare PV charge controller.  If I hooked up this spare CC to the batt charger, would this in effect make a "float" type system.??

Secondly.  Given the long time (is 2yrs long.? not sure), I have had these and the fact they have not really been discharged/worked...is sulphation a potential concern at this stage.? I have looked into the separate cells and see silver colour on the plates..??

My thought is to run all the lights and the furnace (sans propane), and let the batts go down from a full resting charge (approx 12.60 - 12.70V), go to .... where(?) in terms of Voltage.  12.15-12.25..??  to give them a 20-25% DOD

Have done specific grav test with hydrometer however and reading is in red at 11.75,  not good me suspects...lol.  Now given that spec grav is so low...would the addition of electrolyte be advised at this time.?

Lots of Q's and will read as much as I can while awaiting advice / comments.

Thanx...big time.  Am beginning to understand that Batts and maintenance thereof is likely the most important subject in RE. Particularly in off grid apps.

rgds..

stk

[nothing to lose]

"Now given that spec grav is so low...would the addition of electrolyte be advised at this time.?"

Never!

Only 3 reasons it should be low, Batteries need charged or they are sulphated or you had a spill. We can probably rule out the spill, you'd know if you turned one on it's side in your truck right. I did that once in a van, I knew! That would be the only time acid should be added, after a leak or spill, and sometimes not even then.

You should probably charge them up normally first, then check again. Remember those are probably around 150amphours @ 20 hours rate. Daily self discharge is probably close to 2amps.

"My thought is to run all the lights and the furnace (sans propane), and let the batts go down from a full resting charge (approx 12.60 - 12.70V), go to .... where(?) in terms of Voltage.  12.15-12.25..??  to give them a 20-25% DOD"

I suspect the 12.6V-12.7V resting charge may be a surface charge, did you check that right after removing the charger or after they had been sitting awhile with out charging? Right after charging batteries will have what's called a surface charge which is higher than normal, it will go away after a short time and the batteries will reach a lower V resting charge. If your Specific gravity is low, and you have 12.6V showing as a charge, I suspect they may be sulphated and that you checked Voltage right after taking off the charger. I could be wrong perhaps.

I would run them on a desulphater or pulse charger for awhile.

I have a Vector charger and just bought a Shumacher a couple days ago. Both from Wal-mart. Both do desulphation, Vector I can select that mode myself, the Shumacher it only goes into that mode when it thinks it's needed. Not sure which I preffer yet.

 If you got one or know someone with one, I would do that, or build your own. Somewhere here is info for building one.

I don't really know of any reason to run them low just to be doing it myself, but if you wanted to then I'd say around 11.5V should be ok. Don't know what % that is, but it's not far enough down to hurt anything.

[steak2k1]

MST..Thanks for the info.  I will recharge and then let the batts sit for a full day.  I too am thinking they <U>may</U> be somwhat sulphated...just not sure.  I did check the level of charge right after however (1 hour or so), after charge was done.

Currently they are on the 2 - 50w panels right now in a somewhat cloudy day here in Calgary. I'm gonna have a look and if they're not doing much, I'll the use batt charger on a 2 amp setting till sometime late this evening.

The reason I wanted to run em down and actually do it a few times, I read in an FAQ that Woof suggested on Batts - that for deep cycles, it may take up to 20+ discharges and re-charges to get these ones up to their full AH potential..??

Thanx..I'll be back

stk

[steak2k1]

sorry...Should've read  "thanx - nothing to lose"  not MST..ye gads..musta had my readers on back side of duh head.

stk

[steak2k1]

OK:  Batts charged for a full day (through converter).  Pulled plug this AM around 10:30.  Checked Voltage at 5:45PM and read 12.66V rechecked again at 8:00PM and reading was 12.65.  I am assuming now that is typical Voltage reading at rest.

difference would be attributable to self discharge rate.?  Batts are at full charge.?

stk

[steak2k1]

I should add that the hydrometer reading was on all cells as follows: read just after I posted last meassage.

Batt1:  12.25 across all three cells

Batt2:  12.15 on 2 and 12.25 on third.

Now given that the hydroimeter readings are still low, and that the bats were emptied completely of all electrolyte, flushed with de-ionized water and refilled with electrolyte (by a proffesional with access to sulphuric acid solution for batteries),

..do I have a set of sulphated batts..??

rgds,

stk

[ghurd]

I would say charge them for another day or 3.  They sound OK to me, just not fully charged. The pair of 50W panels and a 2A trickle charger are not going to get them full in a day.

Also, watch the voltage for the first half hour of charging.  

If the voltage comes up kind of fast for the first few minutes, then goes up slower for the rest of the half hour, that is kind of normal.

If the voltage goes up very fast and doesn't really slow down, that could mean something is wrong.

Watch the voltage when the charging is removed.  It should drop 0.25~0.5V very quickly, then take a while to go slowly go down.

Let it sit a day, then do a light load test, like a 12V 50W bulb for an hour. The V should drop some, but bounce back after the load is removed.

Just because they are not perfect doesn't mean there isn't a lot of life left in them!

G-

[steak2k1]

ghurd:

I did have them charged by a friend that manages a Battery world here in town. He put them on for a full 28 hours and then ran a capacity test of some sort. (I wasn't there to see it), but he tells me the batts are fairly good shape at about 80%  or approx 90AH capacity.  He told me of a product called "Battery Equaliser", some form of water based product that apparently can be helpfull in potentially sulphated batts as opposed to buying a Pulse hi Freq de-sulphating charger initially.

I would be curious to hear from here whether anyone has used this product and how their results were.  From what I see on their website, (www.batteryequaliser.com), many reputable companies have tried this product with fairly good success.  Anyway, I managed to actually find some here in Calgary at CDN tire (in the sporting goods section..go figure), and have added this product to the cells as per directions.  

Now I am in process of discharge/charge (50%) and will have the batts tested after about 5 cycles to see if there is any actuall improvement and if the $32.00CAD was a waste or worth $$ & the time and effort.

Rgds,

Stk

[ghurd]

Search here about "EDTA".

And 80% isn't too bad.

G-