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Old Jul 09, 2011, 02:10 PM
jrb
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Care and Feeding of Pbs; and water too!

Recently saw the following posted by me number one battery Guru; and got to thinking that maybe we need thread – maybe even as a sticky.

Quote:
Originally Posted by everydayflyer View Post

As I have posted in the past Pb is more complicated charging correctly than LiPolys.

Standard charge rate for flooded cell deep cycles is 1/3C .

Some can be charged much faster ,one of my sealed (AGM) 48Ah can be charged at 100 amps.
Best charger I am aware of is an Iota charger / power supply with a IQ4 Smart charge controller.

Bulk 2.46 per cell
Absorption 2.36
Float 2.26

FYI When the FMA engineer was developing the charging algoratims for the POWERLAB8 he found out very fast that routines used by most automobile chargers sucked big time and that it was common for the typical battery to fail in less than 100 cycles.

I use my IOTA 45 amp. with an external IQ4 Smart charge controller most of the time for my deep cycles.


Charles

In my case I have three Group 24 / 85AH Deep Cycle 12V Pbs (abbreviated from now on as DP) that I use primarily for Zip Charging my A123 powered planes: DP-2S for A123-6S & DP-3S for A123-10S.

I also use them to power my LiPo chargers – wired in P to keep use equalized.

For example yesterday I took out about 30AH and used two of them in combos of DP-2S & DP-2P.

I Bulked them as 2S to 28.8V @ 20 amps via my MasTech 5020; then as 2P with my Schulze 330s for Acceptance (it also seems to do Equalization). And then finally back on my Minder for float/desulfation.

Had hoped my new iC3010B would have been “smarter” than just a float charger


This is my 1st couple of weeks of doing this so no long term data yet.


How’s this sound and what other’s doing?

TIA,

Jim
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Old Jul 09, 2011, 03:01 PM
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Looks like you have a sound approach for long term good health and maximum capacity.

Since I only use my deep cycles on weekends, my approach is a little less involved. I simply strap them in parallel after a day of flying and connect them to my Battery Tender and it does all of the 'heavy lifting' for me. My deep cycles are always fully charged and ready to go when I hit the field. As Ron Popeil says..."set it and forget it".

Battery Tender makes different models that have optimized multi-step charge algorithms for all Pb battery types. Have been using them for years and could not be more satisfied.

Mark
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Old Jul 09, 2011, 10:44 PM
Expo/DualRates = Lack of Skill
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A 12V lead-acid battery has 6 cells in series and is therefore a 6S battery.

Two 6S (12V) lead-acid batteries in series become a 12S (24V) battery.

Single unit 3S and 12S deep cycle lead-acid batteries exist, assuming there are only 6S is an error.






Courtesy of the Department of Physics and Astronomy, Michigan State University.
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Old Jul 10, 2011, 08:48 AM
jrb
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Thanks for that info typeRA; to reduce the Pb S confusion I attempted to use a new abreviation: "Deep Cycle 12V Pbs (abbreviated from now on as DP) ".

How big is your DP and what the Bulk charge rate of your Tender?

I realy like th info in their pdf; though they never realy defined the values for the paramters like: A, B, etc.

Though later they gave info for a 50AH battery -- bulked @ 20A = 40% C, a little highre than what Charles had listed.



I started this quest as my Battries no longer trip the Battery Minder's float/desulfate mode when all in P. Any sigle does, and most combos of 2P do; but not 3P.

Hoping the higher Bulk rate gets them going compared to the measlye 6amps I used before this quest -- like only 2amps w/3P.

They are less than 6 months old and have a 1year replacement warranty -- just wondering if something isn't quite right with them?
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Old Jul 11, 2011, 08:56 AM
jrb
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Hi Mark!

Do you know the Bulk charge rate of your Tender?

Jim
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Old Jul 11, 2011, 10:04 AM
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Jim,

I use the Junior which has listed bulk charge rate of .75A. This works perfectly for me as I only use my deep cycles on weekends and rarely pull over 40Ah out of each battery. Plug them in on either Saturday or Sunday evening and they're fully charged and ready to go by the following weekend. On rare circumstances that I am using a good portion of available capacity on consecutive days, I charge them with one of my iChargers.

Mark
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Old Jul 11, 2011, 11:37 AM
jrb
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Thanks Mark!

Trying to learn more about the need to Bulk them up quick (@ 1/3C) or not.


Jim
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Old Aug 16, 2011, 11:11 AM
jrb
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Don't forget they made need water too!

Wonder how often Charles need to add water to his 125AHs?
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Old Aug 16, 2011, 12:32 PM
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Haven't really kept track but I check them atleast 4 times a year and most times they need non or very little. Well very little as in about 24 oz. between the 12 cells.

Just as a reminder to others they need to have levels checked and toped off (?) after they have been charged.

Charles
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Old Aug 16, 2011, 12:52 PM
jrb
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Thanks Charles!

do you ever check the Specifc Gravity of each cell?
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Old Aug 16, 2011, 03:31 PM
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I misplaced my gage and have not checked it in over two years now. Mine are 4 years old now and still doing OK but I have not done a capacity check on them since back in April or May.

Logic says they are living on borrowed time and if I was flying A123 and Zip charging like I was when they were new I would most likely have to replace them. Since chargers work fine down to 10V and they manage to hold 11V plus under my normal charging loads I may get another year or two out of them.

Charles
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Old Jan 27, 2012, 06:50 AM
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Update

The MasTech > 330d > Minder method seems to be working great!

My DPs are working very well and show no issues as they had with the cheap car charger and minder method.
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Old Jan 27, 2012, 12:50 PM
jrb
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Thanks for the info Pete:


Quote:
Originally Posted by PGR View Post

As far as I'm concerned, CTEK chargers are unrivaled when it comes to maintaining 12V lead-acid storage batteries. I say that as someone who has spent more than 25 years in the car, truck, industrial equipment, and recreational vehicle repair trades and my specialty in all those fields was electrical diagnosis and repair.

Look at the CTEK Multi US 7002 and the CTEK Multi US 25000 The first can charge at 7A, the second can charge at 25, and both can be used as 12V power supplies with no battery connected.

These chargers aren't cheap, but you can leave them connected to a battery indefinitely and they WON'T harm the battery. I have the 7002 and I just love it. It will easily charge my Group-27 105Ah deep cycle battery overnight and I just leave it connected if I'm not using the battery. My battery is one of the old fashion "flooded" types with removable caps to check the electrolyte and I haven't had to add any yet after nearly a year of maintaining it as I described with my CTEK.

Pete
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Old Jul 06, 2012, 07:03 AM
jrb
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Be advised of the heat -- most chargers are not temperature compensated.

My Minder doesn't auto toggle to float/desulfating with the heat; and the 330d doesn't reach full either.

So, I'm terminating @ a bit lower @ 14.2volts and manually switching the minder.
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