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RE: 9.6 Bigfoot Dual Batteries
Would you reccomend it over an on board charger/inveter?
What would be reason for extended high voltage?
Though batteries seems to be a moving target Ops intent was 2 or 3 AGMs. In your opinion or information you based your decision on would it be more beneficial for Bigfeets intent and usage?
mark
I am having surgery today and will be out of pocket for the next few days. I understand the OP want as little maintenance effort as possible. I feel the same way as I have been 100% AGM since 2009.
The voltage is not extended, it is necessary until float. The converter/charger is primarily a power supply and that is why it is so quick to fall back to 13.6V.
Temperature compensation is very helpful as it adjusts the charging Volts according to the battery temperature. This is a key factor in unattended charging. Read the specs for the Xantrex Truecharge2. I don't have one but it will give you a good idea of what I would trust to leave unattended on my AGMs.
The portable charger measures its own temp, so it needs be placed so it can know the battery temp if left unattended.
I trust my two solar controllers to run unattended year round. The typical converter/charger is no where near as smart. I don't leave my WFCO unattended. Details of my systems are in my profile.
HTH;
John
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full_mosey
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05/22/13 07:25am |
Truck Campers
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RE: 9.6 Bigfoot Dual Batteries
Where did a portable charger idea come from? The Schumacher would be a nice unit to have on hand-Im really not sure bout using for camper-Id dump that idea. If its a matter of cost get a smaller unit-(Best has the 60amp 4 160)get a unit designed for the task. Maybe just me...I did note comment on the portable being able to increase voltage to 16v if a load is also present while charging? If I were to spring for 3 31 agms Id want to insure I could maintain them.
I have a portable Schumacher sc1200a 2/8/12A.
1. It has ambient temp compensation that most converter/chargers lack.
2. It holds 14+V where many converter/chargers drop to 13.6V too soon.
HTH;
John
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full_mosey
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05/21/13 09:50pm |
Truck Campers
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RE: Amps jumping around on AGM finishing charge
Jim;
Could the Amp bouncing be related to the bubbling? IMHO, bubbling is not normal.
It is odd that you are the only AGM owner that has reported hearing any bubbling unless performing recovery charging on known problem AGMs. Are you sure your batteries are healthy and the valves have not been compromised?
There was a poster that reported chalking on his AGMs. It turned that Lifeline knew about a few AGMs that had bad valves and they shipped new AGMs at no charge. You might want to call Deka.
What Amp acceptance reading indicates fully charged to you? The only time I see zero Amps is with my SC-1200A 2/8/12A Schumacher portable charger because it floats with an on-off method every few seconds.
HTH;
John
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full_mosey
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05/21/13 02:02pm |
Tech Issues
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RE: Amps jumping around on AGM finishing charge
I suspect outgassing below the venting level is as good for AGMs as it is for flooded batteries...in moderation. But it's a tightrope to walk.
Jim
What is the payback for walking the high voltage tightrope?
How many years life can you gain opposed to how many you stand to lose?
I trust my Morningstar controllers to maintain my AGMs unattended. I have never heard any of the sounds of internal gassing or vent gassing, and I don't ever intend to! :)
I have never seen zero Amps in any charging tests. I don't believe 100% fully charged is a necessary/affordable goal. When Amps are below 1% of AH20, I consider my AGMs charged enough.
HTH;
John
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full_mosey
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05/21/13 11:40am |
Tech Issues
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RE: Charge controller recommendations
Aside from Salvo's link below, nobody has really suggested a PWM controller. Especially one that would be considered reputable, yet cheap enough to be a viable alternative to MPPT.
MS SS-20PWM.
If you are staying with 2x75W, then I recommend the 10A model.
I use one on 2x85W panels.
HTH;
John
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full_mosey
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05/20/13 01:15pm |
Tech Issues
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RE: 9.6 Bigfoot Dual Batteries
What are everyone's thoughts on a Powermax Boondocker 75amp converter/charger for my 3 group 31 AGM's? I have a Honda 2000 that should power it fine.
If you haven't already got the 31s, check the discount clubs for 6V AGMs for $169 that might fit.
The last time I checked, Boondocker only does 13.6V after bulk. Most converter/chargers are like that. It would be ok if you are only interested in bulk charge followed by a good solar charger that holds 14+V in the Absorption stage.
Inverter/chargers seem to have smarter charging, but can be pricey if you do not also need an inverter.
Take a look at the Xantrex Trucharge2 as it has a nice charging profile, also pricey.
Some portable chargers, with an AGM setting, are ok for AGMs.
HTH;
John
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full_mosey
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05/18/13 06:25pm |
Truck Campers
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RE: Charge controller recommendations
What is the Voc of the 75W panels?
Three in series may exceed the 75Voc limit of the MS MPPT 15.
Three in parallel should work with the MS SS-20 PWM.
HTH;
John
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full_mosey
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05/17/13 01:44pm |
Tech Issues
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RE: What is the Ideal Battery Charging System?
IMO forget the expensive clamp meter for now anyway. The 10 amps feature on the cheapo multimeter is not required for most things, but is useful for the odd thing. You just want the voltmeter part for now.
You can use the 120v setting to check campground pedestals. You can use the DC voltage setting to check any thing in the RV that is 12v. eg, to see if the converter is working at 13.x v and you are not just on battery at 12.x volts with a duff converter.
While camping off grid you want to know when it is time to recharge. Your "morning voltage" before you turn on stuff will start at say 12.65, then next day it might be 12.45. You want to stay above 12.15.
So you see at that rate next day it will be 12.25. Hmmmm. Ok that means if you wait another day it will be 12.05, so you better recharge at 12.25 to stay above 12.15.
X2!
I am 100% AGM and had to learn to read battery health without a hydrometer.
I use BFL's technique as well to forecast when I need supplemental genny/shore-power charging. Of course, you must have enough AHs in your battery bank to last more than a day.
I have a meter called a Turnigy. It has a few extra features that make it better than a typical hand held meter(HHM).
One feature is that it shows the lowest voltage since attached. Low voltage can warn you if your circuit boards in your propane fridge might shut off soon. In my case, it warns me about my 12V fridges.
After I recharge I reset the Turnigy $30.
If placed in-line between a source and load, you can get Amp data such as accumulated AHs, Watthours, and Highest Amps.
HTH;
John
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full_mosey
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05/13/13 08:56am |
Tech Issues
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RE: What is the Ideal Battery Charging System?
Homeless by Choice;
If you are getting vented flooded lead acid batteries, you are already getting good advice on the necessity of a good hydrometer.
Just food for thought; there are folks around here with 9+yrs on AGMs who believe they are better off. AGMs are lead acid as well. We cannot use a hydrometer, but somehow we get our batteries to last. Now when you say 'fully charged' it is true we don't really know!
We do like that we don't have a hydrometer though. We don't deal with acid mist, hydrogen gas, dipping for acid, adding water, or bubbling acid on a regular schedule. If you are comfortable with that, then choose FLA. One man's chore may be another's pleasure.
We quietly charge our batteries and use the rest of our time RVing. :)
HTH;
John
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full_mosey
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05/12/13 02:31pm |
Tech Issues
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RE: CampingWorld has lost another Customer and refs for life!
I just looked up that Powerhouse 2100 generator at CW and Amazon. CW offers it for $724.99 and $60.00 shipping i.e. $784.99.
...
In March, I got a Yamaha EF2000IS for $891 shipped. It took me 4yrs to learn my lesson. Some gennys just look quiet.
You too can buy cheap and buy twice! :)
HTH;
John
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full_mosey
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05/11/13 05:11pm |
Camping World Accessories
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RE: How is Tracfone and/or Virgin Mobile internet service
I have a Virgin Mobile mifi. If bought from Wal-Mart, you can get 1GB for 30 days for $20.
There is another Wal-Mart program that may be cheaper.
I also carry a T-Mobile USB that I have never activated because I have not needed it!
HTH;
John
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full_mosey
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05/10/13 07:39pm |
RVing in Canada and Alaska
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RE: RV Parking Rights Manual?
You may want Overnight Parking Code of Conduct.pdf . You may need to join, but it is easy to do.
Otherwise, are you addressing keeping your RV on your own property?
HTH;
John
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full_mosey
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05/10/13 07:34pm |
RV Lifestyle
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RE: Charging antimony-free VRLA batteries without float
As a practical matter, my Deka AGM batteries are 5 years old, and they have been on charge 24/7 when we are not on the road. My converter is a Xantrex that puts out a float of 13.6 volts. The batteries seem to be performing fine.
So far so good. 13.6 is barely over the specific float voltage spec I got from Deka, and within the float range they allow, I think.
I need to calibrate my volt meters. They agree with each other to within a few hundredths, but the volt meter in my charger is sometimes many tenths off one way or the other, and not by a constant amount.
Jim
Jim;
There you go Obssessive-Compulsive-Disorder(OCD) on Volts again! :)
Set your chargers for 14.4V temp comp and calibrate your Amp meters!
Take a deep breath, let it out slowly while saying Amps, Amps....
How many AGM owners with 5-10yr old batteries it going to take?
MY solar two stage MS SS-10PWM doesn't even have a float stage! It simply holds 14.4V temp comp and tapers Amps so low that the battery reaches stasis. Rinse and repeat every day. This is the system that runs my 12V fridge and freezer. We're talking about my beer and ice cream, man!
Think Amps! ;)
HTH;
John
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full_mosey
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05/10/13 04:38pm |
Tech Issues
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RE: Charging antimony-free VRLA batteries without float
You never want to either. It is an extreme recovery procedure for an otherwise dead battery. Lifeline has one for batteries that have run dead and some other recovery procedure too. I used only as a last resort and it did work, but guaranteed the battery was stressed. It was not valve noise, it was a bubbling/crackling sound inside the battery.
Jim
Ah! That clears things up considerably. Your AGMs were already ruined. I had a grp31 trolling FLA that I ruined and it sizzled and crackled when I tried to recover it with a VEC1093.
It had run dry over Winter because I brought it inside and used it with an APC 1250 UPS without checking or adding water.
HTH;
John
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full_mosey
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05/10/13 04:15pm |
Tech Issues
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RE: Charging antimony-free VRLA batteries without float
I just recently got one of those HF I-R guns. I will be curious to read your experiences in various battery temps.
Maybe I need a stethoscope. I definitely don't want to hear a valve make any noise. Can you explain the bubbling noise more as I have never heard any.
Optima says unlimited Amps but cap the Volts and Temps. My approach is to focus on getting Amps over Volts into my AGMs. That is more aligned with AGM mfgr specs.
Both solar controllers are MS PWM with temp comp and set for 14.4V and 14.35V, the WFCO converter/charger never does more than 13.6V and the portable has an AGM setting and ambient temp comp.
HTH;
John
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full_mosey
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05/10/13 03:31pm |
Tech Issues
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RE: Charging antimony-free VRLA batteries without float
Hi Jim;
As a hobby or test case I can understand your curiosity about your AGMs. Thanks for posting your details as the info is beneficial to any interested parties, including myself.
An AGM is pressurized. I do believe there is capacity loss in the same manner that a tire loses pressure simply by the movement of atoms. I believe that is baked into the design. However, to deliberately walk a high voltage tightwire that could possibly lose gas, means a loss of H and O that is not baked into the design, is asking for trouble. I trust my two MS PWM controllers, with temp comp, to work unattended every day.
If the valves are intact, it should be nearly impossible to reintroduce H2O because AGMs are watertight submerged to 30ft. Another plus in a marine use if there is a concern for Chlorine gas.
If the valves are broken, then you really don't have a proper AGM battery. Yes it has a-g-m but the chemistry is not to spec.
HTH;
John
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full_mosey
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05/10/13 01:11pm |
Tech Issues
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RE: Small (5W) solar panel does work to keep batteries okay
Here is a Trojan document that may help.
Look at the self discharge rates for 86F and 42F, or .0075/wk and .0015/wk respectively.
Note that when the temperature was halved, the discharge rate was 1/5. If you halve the temp again to say 21F, doesn't it stand to reason the discharge would be reduced by 1/5th again?
That gives 1/25th of the 86F rate of .0075, or .0003/wk.
Given 28 weeks in Nov-May x .0003 is a drop is SG of .0084SG, and a drop to 1.28 - .0084 = 1.276.
The fully charged table allows that 1.250 is freeze proof down to -62F.
Think about an AGM that starts at 1.3SG and has a much lower self discharge rate. How many years?
HTH;
John
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full_mosey
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05/10/13 12:35pm |
Tech Issues
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RE: Charging antimony-free VRLA batteries without float
I have been floating mine to manufacturer spec when temp is close to 77, and using the PWM solar controller tweaked to the recommended charge voltages (on battery temp compensated) the rest of the time.
So far so good. I only see outgassing (like a bubble a minute) if the temp climbs above 90 and the battery is on float.
I guess my biggest takeaway from this paper is running say a tenth of a volt under temp compensated ideal float may not be the end of the world. My own experience is that a tenth over on AGMs could potentially be slowly destructive.
Every bubble causes me pain lol.
Jim
Is this an OCD in trying to stay on the highest voltage tightwire? If so, why? What are the expected improvements?
I would be very concerned if my AGMs were bubbling at all. Do you mean to say you are exceeding the valve pressure and releasing gas?
IMHO, every bubble that escapes translates into lost capacity. That is a no-go for me.
A proper temp compensating charger should prevent any gassing at the plates. If plates are bubbling, does charging take place under the bubbles? Is gassing really needed with AGMs, after all, there is no need to stir? What good can come from any bubbling?
HTH;
John
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full_mosey
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05/10/13 11:10am |
Tech Issues
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RE: Small (5W) solar panel does work to keep batteries okay
The OP is in "OTTAWA CANADA".....can you spell -35 degrees..... only a fool would let his expensive batteries sit for 6 months in those kind of temps.
If the battery is going to freeze when fully charged, it doesn't matter how many watts of solar are used. :)
A cold battery will have a nil self discharge rate.
If stored indoors, how is solar going to work?
HTH;
John
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full_mosey
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05/10/13 09:24am |
Tech Issues
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RE: Trade offs of DC-DC vs. PWM for Absorbtion and float
Hi John,
My understanding is the pulses are very short and very fast. I.E. way beyond the ability of a Turnigy to display.
That explains the Volts as that would be the instantaneous Volts of the battery. It would take longer than a pulse width for the Volts to start dropping.
As I said before, what about the Amps. If the ON pulses are short compared to the OFF pulses, why don't I see the Turnigy catch a low, or OFF pulse, Amp reading ever? All I see is the expected slow tapering until float where I see constant milliamps.
HTH;
John
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full_mosey
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05/09/13 09:02pm |
Tech Issues
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