Finally figured out a routine..batteries

smkettner wrote:

One week does not give IOTA a chance to repeat the weekly boost charge very much. So you are at 95%/98%? I would think you would hit 98%/100% after two or three boost charges. Although maybe the voltage is just not high enough to get 100%.

Another reason to look at solar with a good controller to pop the voltage for a few minutes each day.

I understand that sulfation sets in pretty quickly if you've followed some of BFL's exploits (backed up by some discussion/documentation). I can tell you with certainty that an occasional 15 mins of 14.7V doesn't do it on these batts (apparently not with BFL's either). I have tested that with my manual charger. That IS good with stratification though. Answer this question. If ~15.5V takes 2-3 hrs to get it done (one session), how does 15 mins of 14.7V supposed to be any better especially when each session is a week or so apart? Battery maintenance is not a hands off affair. But I have managed to mostly automate it though with this last test.

mena661 wrote:
I finally figured out a routine that gets my batteries back to 100% full everytime. Since I only charge at home, I do the following:

1. A week on the converter. IOTA 55A w/ IQ4. This gets them back up into mid to high 90% SOC range.

One week does not give IOTA a chance to repeat the weekly boost charge very much. So you are at 95%/98%? I would think you would hit 98%/100% after two or three boost charges. Although maybe the voltage is just not high enough to get 100%.

Another reason to look at solar with a good controller to pop the voltage for a few minutes each day.

Pauljdav wrote:
I don't understand why the converter can't do the 100% charge. On my PD if I think it should stay in bulk mode I just push a button and I have 60 amps at 14.4 volts again but I never felt the need to.

Paul

If you read some of the battery manufacturers documentation, they'll say that an "overcharge" is required to get their batteries back to 100%. This backs up our resident battery engineers, MEXICOWANDERER's, recommendations on the proper care and feeding of batteries. The problem with converters in general is two fold, absoprtion charge is too short and there's no overcharge at the end to cram that last few percent into the batteries. Now, there are many here that have had long life from their batteries with just a good 3 stage converter. They can keep doing that. I am only interested in the proper care of MY batteries. Specific gravity doesn't lie and anyone that performs those checks can back up what I'm saying easily.

I don't understand why the converter can't do the 100% charge. On my PD if I think it should stay in bulk mode I just push a button and I have 60 amps at 14.4 volts again but I never felt the need to.

Paul

hershey wrote:
Is that really necessary? Not a flame, just an honest question. What difference is 90% charge to start with as opposed to 100% charge which will probably burn off to 90% before you actually start to use it. :)

The last 10% is the hardest part of a battery charge session. When boondocking I just try to top off each time but I don't worry about getting that last 10%.

No worries! :) What ktmrfs said is exactly it. BTW, my batts stay on float between camping trips so they are at 100% before each trip (I have verified that with a hydrometer enough times that I no longer need to check). Since the IOTA does periodic 15 min charges at 14.7V, I don't need to do the destratification thing anymore either (these tall batteries are much more susceptible to stratification than GC's).

BFL, sorry to hear that about your Exides. Sounds like L16's are in your future! :B

What I do too (as posted numerous times :) )

Only snag is my Exide GC135s don't like the same routine as my Interstate GC2 XHDs. (I have a pair of each as a bank of four, treating them as though the same) even though they are different.

The Exides are 5% antimony, but the Interstates are some new magical thing they invented a couple of years ago when they stopped using US Battery U-2200s etc. "Pure Lead" in the ads, eg. (not likely!)

At first the Interstates took only one Equalize off the 1093, but the Exides took two in order to get back to baseline SG. Now I am on solar all summer and I find SG is staying up there without having to Equalize. Great.

EXCEPT--Whoa! The hydrometer sucked up some black stuff on the Exides recently. All clear on the Interstates. Mex says call the coroner if you see the black stuff in the hydrometer.

The hydrometer routine says to do four sucks each cell to get a proper reading. The black stuff only appears after the third suck.

My answer to this problem is to only do one suck on the Exides and all is clear. So there is nothing wrong with those one year old batteries!!!! :( They still perform up to full AH near as I can tell, but I will do a load test this fall when things calm down.

Anyway, it seems that this solar routine where you hit 14.6 every day and so forth may not suit all brands of 6v battery. The Interstate GC2 XHDs are loving it. The Exide GC135s--- not so much.



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hershey wrote:
Is that really necessary? Not a flame, just an honest question. What difference is 90% charge to start with as opposed to 100% charge which will probably burn off to 90% before you actually start to use it. :)

The last 10% is the hardest part of a battery charge session. When boondocking I just try to top off each time but I don't worry about getting that last 10%.

for longest battery life (charge/discharge cycles) you DO need to get batteries back to FULL charge periodically. If you don't you risk sulfation damage. Most mfg are pretty specific about getting them back to initial SG periodically and NOT make a practice of only partial charges.

you don't need to do it every cycle, but should be done periodically. I do somewhat like menna. When I'm home, I plug it it, charge it with the PD unit till it quites (usually about a day), then use the vector which has a higher bulk charging mode voltage, closer to what trojan recomends. My results are that after 8 years on a pair of GC that are discharged to well under 50% SOC, often to about 30% SOC, about 30 times/year, SG on each cell is still at the 1.280 that a new set is at.

Getting the last 10% when out camping is an excercise in futility so I don't bother when we are boondocking, but try to bring them up to 100% as soon as a hookup is available.

Is that really necessary? Not a flame, just an honest question. What difference is 90% charge to start with as opposed to 100% charge which will probably burn off to 90% before you actually start to use it. :)

The last 10% is the hardest part of a battery charge session. When boondocking I just try to top off each time but I don't worry about getting that last 10%.