mena661
Southern California
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When I posted THIS THREAD, I thought that my batteries were heavily stratified but it seems I was just wrong about what stratification was. In that thread they were measured at a SG of 1.300 @ 63F. Well, I had a chance to test them again today and the SG was from 1.290-1.295 @ 70F. So it seems it does take a while for batteries to "break in". In my case, almost a year. Interesting because I thought they had to be cycled a bunch before this happened. Mine have been cycled less than a handful of times since I purchased them.
2009 Newmar Canyon Star 3205, Ford F53 V10
Trojan L16 6V's 740 Amp-hours
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MEXICOWANDERER
las peñas, michoacan, mexico
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It's a complicated area involving TDS consisting of plate material as well as stratting of H2SO4. I stayed the heck away from the thread at risk of complicating it to the point of complete uselessness for consumers. Pb is heavy Mena661. It does not act like lighter compounds like magnesium or iron in dissolved solids form. Fresh sheds will eventually coalesce and precipitate to the sediment chamber on the floor of the cell. I've said too much already; excuse me.
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mena661
Southern California
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A lot of this is complicated BUT... Although it might be over our heads, there will still be bits that we CAN understand and explore or just ask tons of questions till we get what we need. I am wondering about the "break in". Care to comment on that? Thanks Mex.
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09FLSTC
Out West
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I'm only presuming they are AGM. Data is getting scarse on flooded but a lot are still out there.
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MEXICOWANDERER
las peñas, michoacan, mexico
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VRB are reluctant to stratify their electrolyte. Absorbed glass mat means exactly that the acid does not "mix" within the separator mat.
Standard flooded RV batteries can be agitated just fine by rocking them over to say a 35 degree angle then returning them level, and then repeating the process a half dozen times.
A good solid charge to the point where acid in the cells bubble for twenty minutes is the best way to avoid stratification. I would do this every 2 weeks.
As a general example I use a Harbor Freight 10 amp charger on a disconnected Wal-Mart group 29. I set it to manually charge at 10 amps and let the battery charge for a half hour every 2 weeks or a full hour every month or so. The top of the battery remains bone dry and electrolyte levels have not changed perceptibly.
I've yet to see a "smart charger" that is any "smarter" than moron level with regard to top charging a battery.
Certain premature death awaits flooded batteries that receive modest charges after sitting for months. Charge batteries well and truly full rather than let them hibernate at static charger float voltage month after month.
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mena661
Southern California
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09FLSTC wrote:I'm only presuming they are AGM. Data is getting scarse on flooded but a lot are still out there. Mine are flooded.
mexbungalows wrote:
A good solid charge to the point where acid in the cells bubble for twenty minutes is the best way to avoid stratification. I would do this every 2 weeks. I remember you giving me this advice before and I try to do this but should do this regardless of the SG reading?
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bryanl
Reno, NV
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re: "A lot of this is complicated BUT... Although it might be over our heads" -- there are often ways of providing models of complicated things that people can use to help them understand what they need to know. This is where a good educator earns his wages.
Quote:A good solid charge to the point where acid in the cells bubble for twenty minutes is the best way to avoid stratification. I would do this every 2 weeks.
...
Certain premature death awaits flooded batteries that receive modest charges after sitting for months. Charge batteries well and truly full rather than let them hibernate at static charger float voltage month after month.
This advice is very hard for some to accept based on responses I have seen in some threads. It is especially pertinent to the RV solar boondocking crowd and the RV storage issues.
From what I have seen, though, following suggestions like this are extremely important when looking to maximize RV battery performance satisfaction.
Some of the issues here involve the classic equalization treatment that comes up now and then, desulfators (e.g. http://leadacidbatterydesulfation.yuku.com/ ), improvements in battery charge techniques and battery sensing, and battery monitoring devices. The specific gravity vs voltage debate and bank configuration issues are relevant as well.
A first step, from what I see, is to actually accept that a battery is not a simple electric energy storage device where you can measure net energy flow to determine how much energy you have left in the battery.
Bryan
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mena661
Southern California
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bryanl wrote:This advice is very hard for some to accept based on responses I have seen in some threads. It is especially pertinent to the RV solar boondocking crowd and the RV storage issues.
From what I have seen, though, following suggestions like this are extremely important when looking to maximize RV battery performance satisfaction. I agree but a lot of people would rather just buy another battery than follow what they see as a complicated procedure. I don't mind and, in reality, it doesn't take much time to do most of this stuff (it might seem like it does). Top charging does take some time but it's mostly waiting then checking. Battery cost and geekiness are my motivations though. 
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MEXICOWANDERER
las peñas, michoacan, mexico
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No.
Try to establish unique voltage to SG relationships of your flooded battery in storage. I like to top charge more often of course when ambient temperatures exceed 25C.
When SG droops .05 on any cell I will top charge. When surface charge reads 12.70 or less I top charge. I do not allow more than 60 days to pass without top charging.
Voltage to SG analysis is a gold mine of potential information. This can get so esoteric as to defy the best headache medication :-) However even the most inexperienced (you are not classified as such) can glean mountains of trends & tendencies data from such a database.
Remember this is for your own unique battery. Each one is different and the database "should be" initiated when the battery is at least nearly new and absolutely 100% top charged.
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mena661
Southern California
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Thanks Mex. I'll start a database of this data. I will add that up until the last month or so, my baseline has been at SG of 1.275 @ 68F at 12.8V. It has since increased. Also, up until this point I've only made mental notes of my SG and don't always check voltage. Today I'll disconnect the batteries and let them sit for 24 hrs and check SG and voltage. Is it good to give the batteries some stirring before taking a SG reading?
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