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AGM batteries and charge controller
Yahoo Message Number: 109917
Although I actually passed the electricity segment of college physics, practical application kicks my a**.  My '99 IB has the original solar panels from LD.  What AGM batteries will fit my compartment and what, if any, changes must be made to the charge controller from the panels.  No Costco nearby so what Interstate model will suffice.  Plain English please.  I am glad to be a member of such august electrical experts but most of your intelligent discourse is gibberish to a Georgia redneck like me.
Re: AGM batteries and charge controller
Reply #1 –
Yahoo Message Number: 109930
wrote: My '99 IB has the original solar panels from LD.  What AGM batteries will fit my compartment and what, if any, changes must be made to the charge controller from the panels.  No Costco nearby so what Interstate model will suffice.
--- Just a few comments/suggestions:
 Two AGM battery brands are Lifeline and Trojan; I don't *think* that Interstate makes a 6v AGM battery. You might want to search for additional manufacturers of AGM 6v deep cycle batteries.  The Lifeline website (http://www.lifelinebatteries.com/) offers good information on battery type, selection, and application (click on the “RV” tab), as does the AM Solar website; check the “Education” section.
 You will have to measure the battery compartment in your rig to determine the best battery fit; Lifeline offers a “battery sizing” chart in the above-mentioned section.
 If you go with AGM batteries, you will need to upgrade the charge controller; when I changed to AGMs from the T-105s, AM Solar installed an HPV-22B.  This controller required very little modification to the “hole” from the original controller.  Sorry; I can’t recall the designation of the original controller on my 2003 (other than “30S” or somesuch), but, knowing LD’s MO, it may be the same one as is on your 99.
 AM Solar does offer another controller, the HPV-30DR; you could check this page and find out about its features and applicability to your situation:  http://amsolar.com/hpv30.html
 I hope that you receive additional responses from the battery experts, but, if not, you may want to email Greg or Deb Holder at AM Solar and pose your questions.  (NB:  I really don’t  have any connection with AM Solar other than being a satisfied customer!)

Joan
2003 TK has a new home
Re: AGM batteries and charge controller
Reply #2 –
Yahoo Message Number: 109933
When AM Solar installed 2 8D Lifeline AGMs in our 1997 RB last year, they never brought up the idea of going to a three stage charger. And AM Solar is very familiar with LDs.
 A few years earlier, AM Solar installed 3 8D Lifeline AGMs in our 1997 Foretravel (It did have a 3 stage charger - possibly because Foretravel shipped with GELs in earlier years). I later contacted AM Solar concerned that my alternator charged my 8Ds at 14.4v hour after hour when the recommended float was 13.2v
 AM Solar contacted Lifeline. The following is AM Solar's info from Lifeline:

"I just called Lifeline. Their take on it is that it's not ideal to essentially float them in the 14V range but done periodically they don't feel that it's an issue.  They told me that they have a lot of their batteries in long haul trucks.  The batteries are not lasting as long as they would under ideal conditions but apparently the truckers are getting about 3 1/2 years out of the batteries after driving almost every day, often all day."
 Since I don't drive 8 hours every day, and my RV is at rest at least 6 months a year, I've concluded the 14.4v charging while driving issue might reduce the life of my AGMs somewhat, but it's unlikely to reduce it to less than 5 years.
 On the other hand, GEL batteries are sensitive to charging. Older AGMs were, too. And some folks are not aware modern AGMs are much better than older ones.

So if you have AGMs and are concerned about the LD stock converter over-charging your AGMs while connected to the pedastal just turn it off for X hours a day and put the money towards solar...
 I would be more concerned about starting out driving with your AGMs at 60% and the AGM's demand on your LD's alternator overheating it and causing it to fail in time. I did this once in our Foretravel and saw the alternator voltage drop from 14+ to 12v as the alternator attempted to charge 3 8Ds. The good folks on the Foretravel Yahoo! Group pointed this out to me and recommended I charge the batteries with the generator until they were 80% or more. So when needed I started out the day's driving with the generator running.

best, paul

"Thriving not surviving" - "All of us have cancer cells in our bodies. But not all of us will develop cancer." from ANTI CANCER - A NEW WAY OF LIFE, by David Servan-Schreiber, MD, PhD - See our website at www. LazyDazers.com
Re: AGM batteries and charge controller
Reply #3 –
Yahoo Message Number: 109937
I think the first question to ask yourself is "Do I really need AGM batteries?" As we've discussed here before, they require no maintenance, but they're very much more expensive than flooded-cell (e.g., Trojan T-105) batteries on a dollars-per-amp-hour basis, and there's no significant difference in performance. Trojan T-105s with a ProFill watering system are convenient and much more cost-effective than AGMs.
 The main reason for choosing AGM batteries is not performance; it's the fact that you can add more batteries without having to worry about venting. But if you're planning to stick with just two batteries, AGMs offer no advantage other than zero maintenance.
 To answer your question, the largest AGM batteries that will fit in the existing battery compartment are a pair of 12V Group 27 batteries, and they will only fit once you've removed the battery tray. Two of these 12V AGMs wired in parallel will actually give you fractionally less power (105 Ah at 12V) than a pair of 6V Trojan T-105s wired in series, which yield 225 Ah at 12V.

Andy Baird http://www.andybaird.com/travels/
Andy Baird
2021 Ford Ranger towing 2019 Airstream 19CB
Previously: 1985 LD Twin/King "Gertie"; 2003 LD Midbath "Skylark"
Re: AGM batteries and charge controller
Reply #4 –
Yahoo Message Number: 109939
"If you go with AGM batteries, you will need to upgrade the charge controller; when I changed to AGMs from the T-105s, AM Solar installed an HPV-22B. This controller required very little modification..."
 Joan's original charging controller was an RV-30, and the chances are that's what you have on your 1999 coach. This is a very inefficient controller compared to the NPV-22B; in fact, when I made a similar swap, I observed 20-30% more charging amps than with the old RV-30. That alone is a reason to replace your solar charging controller: you'll get more power from the same panels.
 The HPV-22 controller can handle up to 400 watts of panels; you'd only need an HPV-30 if you planned to have more solar panels than that.

Andy Baird http://www.andybaird.com/travels/
Andy Baird
2021 Ford Ranger towing 2019 Airstream 19CB
Previously: 1985 LD Twin/King "Gertie"; 2003 LD Midbath "Skylark"
Re: AGM batteries and charge controller
Reply #5 –
Yahoo Message Number: 109940
"But if you're planning to stick with just two batteries, AGMs offer no advantage other than zero maintenance."

Andy
 AGMs do have the advantage of being able to accept very high charge levels; enabling them to be recharge much faster if...you have a large charging system.
With today's large solar arrays, bigger alternators, oversize converters and the super-size chargers, built into high-end inverters, AGMs do offer advantages to LDs with the right charging equipment.
If you boondock a lot in the winter,  AGMs, along with a large converter, can significantly reduce generator run time.

Larry
2001 MB
* Not to be confused with Larry W (3000 of my posts are actually from expert Larry W due to Yahoo transition mis-step)
Re: AGM batteries and charge controller
Reply #6 –
Yahoo Message Number: 109941
"Andy"  wrote: This is a very inefficient controller compared to the NPV-22B; in fact, when I made a similar swap, I observed 20-30% more charging amps than with the old RV-30. That alone is a reason to replace your solar charging controller: you'll get more power from the same panels.
--- When this charge controller was installed on my 2003, Greg Holder gave a "ballpark" figure of about a 15% increase in output (from the RV-30 and *one* 85W panel) with the HPV-22B. I can’t say if this is an accurate output estimate because I don’t have a battery system monitor! A 100W panel and a battery system monitor are two more itmes on my "wish list".

Joan
2003 TK has a new home
Re: AGM batteries and charge controller
Reply #7 –
Yahoo Message Number: 109942
"AGMs do have the advantage of being able to accept very high charge levels; enabling them to be recharge much faster if...you have a large charging system."
 True; that's why I used the weasel word "significant." ;-) While AGMs do have theoretical advantages, especially in heavy-duty systems like yours and mine, my sense is that in most RVs the difference probably won't be noticeable.
 For the record, for those of you know don't know my setup, I have five 105 Ah AGMs, and I like them. :-) It's not as if I have a prejudice against this type of battery; just the opposite. But I do recognize that when it comes down to dollars and cents, AGMs are a costly luxury, and I wouldn't want anybody to spend a pile on them and then be disappointed because there's no dramatic boost in performance.

Andy Baird http://www.andybaird.com/travels/
Andy Baird
2021 Ford Ranger towing 2019 Airstream 19CB
Previously: 1985 LD Twin/King "Gertie"; 2003 LD Midbath "Skylark"
Re: AGM batteries and charge controller
Reply #8 –
Yahoo Message Number: 109943
"When this charge controller was installed on my 2003, Greg Holder gave a 'ballpark' figure of about a 15% increase in output (from the RV-30 and *one* 85W panel) with the HPV-22B."
 Greg tends to under-promise and over-deliver--that's one reason AM Solar gets such high marks from its customers.
 "I can't say if this is an accurate output estimate because I don't have a battery system monitor!"
 This is actually one situation where you don't need a battery monitor to make the measurement. Just use the "Array Amps" switch setting on your HPV-22B to look at what's actually coming from the panel, then compare that with what you see at the "Charging Amps" setting. Do this repeatedly over a few days, and you'll get a good idea of how much you're benefitting from the HPV-22's Maximum Power Point Tracking circuitry.
 For example, right now it's late afternoon on a rainy day and I'm seeing 3.1 amps from the panels and 4.9 amps going to the batteries--a 37% increase. That's a larger gain than I normally get, but it points out one of the MPPT controller's best features: it works best under poor lighting conditions (early morning, late afternoon, overcast)... which is exactly when you most need the boost. It's truly a great invention. :-)

Andy Baird http://www.andybaird.com/travels/
Andy Baird
2021 Ford Ranger towing 2019 Airstream 19CB
Previously: 1985 LD Twin/King "Gertie"; 2003 LD Midbath "Skylark"
Re: AGM batteries and charge controller
Reply #9 –
Yahoo Message Number: 109944
"A 100W panel and a battery system monitor are two more items on my 'wish list.' "
 A battery monitor is a great idea, as I've said elsewhere. But here's a caution about adding solar panels to your single-85W-panel rig: what you have now is an 18V panel, and if you were to add one of AM Solar's 22V 100W panels, you'd be throwing away a significant part of its capacity... in other words, its output would be limited by the 18V panel. This wouldn't hurt anything, but it would mean that you weren't getting the full benefit of what you paid for.
 There are two things you can do to avoid this situation. First you can replace your current 18V 85W panel with a pair of 22V 100W panels. That'll more than double your usable power, but it won't be cheap.
 Second, and much less expensive, you can add another 18V panel or two. Many dealers sell this type of panel in various wattages, and AM Solar sometimes has bargains on used 18V panels that they've pulled off the rigs of people who (as I did) have upgraded to 22V 100W panels.

Andy
Andy Baird
2021 Ford Ranger towing 2019 Airstream 19CB
Previously: 1985 LD Twin/King "Gertie"; 2003 LD Midbath "Skylark"
Re: AGM batteries and charge controller
Reply #10 –
Yahoo Message Number: 109947
"Andy"  wrote: This is actually one situation where you don't need a battery monitor to make the measurement. Just use the "Array Amps" switch setting on your HPV-22B to look at what's actually coming from the panel, then compare that with what you see at the "Charging Amps" setting. Do this repeatedly over a few days, and you'll get a good idea of how much you're benefitting from the HPV-22's Maximum Power Point Tracking circuitry.
--- OK; thanks for that. I will stare at the controller display(s) while I  flip switches! ;-)  (I still want a battery monitor, though!)

Joan
2003 TK has a new home
 
Re: AGM batteries and charge controller
Reply #11 –
Yahoo Message Number: 109948
Quote
AGMs do have the advantage of being able to accept very high charge levels; enabling them to be recharge much faster if...you have a large charging system.
With today's large solar arrays, bigger alternators, oversize converters and the super-size chargers, built into high-end inverters, AGMs do offer advantages to LDs with the right charging equipment.
If you boondock a lot in the winter,  AGMs, along with a large converter, can significantly reduce generator run time.
They also are ideal for high discharge currents, losing less energy dissipated as heat in those conditions than flooded-cell batteries. This would be important if you run the microwave occasionally, e.g.

Steve
2004 FL
2013 Honda Fit