What Batteries for a solar system is needed

[Louie Dee]

I just purchased a 2000 34' Excella A/S. The current 4 wet batteries are 10 years old & just died. (Hard to believe). I am not sure of the Solar wattage but it has 2 large panels. Receipts say tey paid $5,000.

What choices do you recommend for replacement. The A/S will live mostly in Phoenix Arizona area.

Also, what gas puller choices would be recommended. I have been looking at quarter ton 8.1 GM products & Ford V-10s. I need to stay under $15,000.
Currently I have a 2001 Chevy 5.3 V8 bought new with 70,000 miles. I use this for my 1990 25' A/S.

I pull in both Colorado & Arizona as a WBCCI member of 2 Units.

Finally, any suggestions on this new purchase would be welcomed.

Thanks in advance from a US Marine on the 4th of July,

Lou De Carolis #8831 formally #1633

[BAB]

For sure, you'll want to use AGM batteries rather than a wet cell. I'm on my second trailer to which I've added a solar install. Think most of us use Lifeline AGM's. You really do want to know the max output of your panels so you can size the battery install accordingly. If you want to go totally early adopter you could go with lithium batteries....but you'd probably need to change out your solar controller. Send a PM to Lewster -- he's a real expert on solar.

[Louie Dee]

Thanks BAB,

Now that you mention it, I was told by the owner that the 10 year old batteries were Lifeline.
Not sure if they were AGM. However, your suggestion will be researched. Are they pricy?

Lou

[lewster]

Originally Posted by Lou De Carol

Thanks BAB,

Now that you mention it, I was told by the owner that the 10 year old batteries were Lifeline.
Not sure if they were AGM. However, your suggestion will be researched. Are they pricy?

Lou

Lou,

Lifeline does not make a wet cell battery of any size. The only batteries they manufacture are AGM, or Absorbed Glass Mat. Yes, they are expensive, but they are the top quality AGM available and regularly last 7-10 years with proper charging.

These require at minimum, a 3 stage 'smart' converter/charger. If you have the original Parallax unit that Airstream provided, they will be toast in short order from the continual 13.6 VDC that a Parallax converter continually sends to the batteries. If your solar charging system is fairly current, then it hopefully has a programmable 3-stage solar charge controller that has a setting for AGM batteries.

Let us know more................

[Zil]

Lew, the batteries lasted 10 years.

[lewster]

Wet cells can last that long, as any battery can if properly charged and used minimally.

The number of charge cycles increases as the depth of discharge decreases. Using Lifelines as an example, you should see 1000 charge cycles at 50% depth of discharge. If you reduce the depth of discharge to only 10%, you can expect 5000 charge cycles.

A lot depends on how you use your batteries and especially how you charge them.


Lew Farber
RVIA/RVDA Nationally Certified Master Tech
Master Tech Energy Systems, Inc.
AM Solar Certified Installation Center
Lifeline Batteries**Magnum Inverters
541-490-6357

[BigButtUgly]

A General Motors 2003 1500HD 4x4 Crew is so close to a 3/4 ton there is really not much difference i.e. axle, springs, frame size etc. Rated to tow 10,300#. A few after market items and some tuning, trans cooler, synthetic oil and Brembos will do you fine. Very good condition =$10K and with new "tweaks" should be under $15K (less a new set of "Keds") 18 MPG

[gecko]

Originally Posted by lewster

Lou,

Lifeline does not make a wet cell battery of any size. The only batteries they manufacture are AGM, or Absorbed Glass Mat. Yes, they are expensive, but they are the top quality AGM available and regularly last 7-10 years with proper charging.

These require at minimum, a 3 stage 'smart' converter/charger. If you have the original Parallax unit that Airstream provided, they will be toast in short order from the continual 13.6 VDC that a Parallax converter continually sends to the batteries. If your solar charging system is fairly current, then it hopefully has a programmable 3-stage solar charge controller that has a setting for AGM batteries.

Let us know more................

Interestingly, we have the original
Airstream provided charger/converter and upgraded our batteries when coach was new (2009) to 4 6v AGM Lifelines. At Lifelune's suggestion, we threw away the AS supplied solar charge controller which shockingly (sorry for bad pun) was one stage and worthless and replaced with a Blue Sky 3 stage programmable solar converter (the one that Lew also recommends). With about 4 weeks of boondocking in two week spells per year--and the rest of our six minutes bags of travel docked in parks with 110 shore power, our batteries are still going strong in year 5. Lew thinks this is because of the solar converter "saving them." We are very careful when dry camping to neveretvthrm go below 50%--in fact, once we converted all our halogens to LED's and added dimmers, we rarely go below 85%.

We will soon prevail upon Lew to change our uur 270 lbs of AGM's (440 amp/hrs of storage; 220 effective at 50% usage) for 84 lbs of 300 amp/hr lithiums (240 effective at 80% discharge) to lighten our 28' International's excessive tongue weight as the final expensive touch to avoid more left front tire blowouts (the extra two AGM's 130 lbs are installed under the left side short leg of the L shaped front couch. This of course is in addition to the full 16" Sendel/Michelin XPS/Centramatics conversion.

[gecko]

Happy Fourth, Lou!

If you get a chance, you should have someone like Lew Farber check out the output if your panels as well the nature of your solar converter. MMPT converters like the Blue Sky that Lew installs wring more out if the same panels. Then you should consider your battery usage. How often do you dry camp without electrical hookups? Do you have halogen lights or have they been converted to LED's--the halogens consume literally 10 times the amp/hrs as the LED's! Next step will be to figure out an average day (and more importantly, night's) amp hr draw. For example for every hour that you leave 10 halogen lights on, they draw 10x 1.0 amps/hr--in 5 hours, those 10 few fixtures will draw 50 amps out of your battery bank. Your inverter (if you're using one to power anything that runs on 110 AC instead of 12v DC) will waste at least 15% of whatever passes thru it. If you're running the furnace on cold nights, the furnace fan draws about 8 amps/hr. So if you run that for 10 hours, that's 80 amps just fir that one appliance. The reefer on propane still pulls about 1-2 amps/hr--and that's 24/hrs per day or 24-48 amps. So those three things alone pull about 150 or more amps per day/night. With two 6 volt AGM's, you''d have 220 amp/hrs in storage of which u can only use half or 110 amps. So without solar charging during the day, you'd be well over in that scenario. Knowing what your incoming amperage is likely to be during the day is critical, obviously, to determine whether you need more storage and whether you'll be able to "top off" during daylight if your stay is more than a day or two. June 21st gives you the longest daylight and the best angle on the panels; December 21st gives you the shortest light exposure at the worst angles. Cloudy days severely limit light available for solar powered recharging.

So an hour or so figuring out (1) your probable actual usage boondocking in terms of total amp/hr draw per night (2) the likely amp hr storage generation during daylight hours based on the max possible output of your panels and the %age you're likely to see in reality based on time if year (sun angle and duration and weather will be well spent. Based on that, you can decide to either (1) augment your battery storage capacity (2) augment your solar generating capacity (more panels, more efficient modern panels and/or an upgrade to an MPPT solar converter) and/or (3) lower your expectations of appliances you use when dry docking. (Convert from halogen to LED, or use 90% less light fixtures, or use sweaters and blankets instead of your furnace when boondocking in chilly places.

Good luck, Lou!

[switz]

Note that the solar panels wattage rating when buying them is a "in theory" number. Their actual maximum output on a bright day is typically 75% of that number. I have eight 100 watt rated panels on the roof and the best I have seen with the Tri-Star 60 MPPT charge controller was 634 watts.

[lewster]

All solar panels are rated according to a set of ideal laboratory conditions called STC for Standard Test Conditions. Switz is correct in that you will never see the actual wattage ratings of the panels.

Depending on the system you have, panel angles, their physical condition (surface condition) and the quality of the air, the panels will receive varying degrees of solar radiance.

We did a quick test a while ago in AM Solar's parking lot when we were looking at the output of the then new flex panels. We found that the maximum output we could attain under a clear blue sky at the maximum sun angle around peak 'solar noon' was 91 watts for a hard panel and 73 watts for a flex panel.

Of course, YMMV! :-))


Lew Farber
RVIA/RVDA Nationally Certified Master Tech
Master Tech Energy Systems, Inc.
AM Solar Certified Installation Center
Lifeline Batteries**Magnum Inverters
541-490-6357

[BigButtUgly]

Trojan T-105 , 4 gives 450 amp/Hr ( @20- hr rate). Heavy @ 62# each. Ebay $139.99 for pick up in Corona CA only. I paid $169.99 each locally + NE tax. So no shipping charge. I don't think UPS or FEDEX can ship wet cell batteries.

[switz]

The Lifeline model 6ct battery (6Vdc at 300 amp hours) weighs 92 pounds and can be shipped via truck. We had four on the front of the Classic trailer in a custom stainless steel battery box.

We recently removed the four Lifeline batteries and their enclosure and mounted four lithium iron phosphate 3.2Vdc at 600 amp hour segments weighing 42 pounds each inside the trailer under the front sofa next to the Magnum MS-2812 converter/inverter. This dropped the tongue weight from 1,375 pounds to just under 1,200 pounds with the ProPride hitch attached.

That new weight is within 25 pounds of what our 25FB tongue weight was with the Hensley hitch attached (1,175 pounds camping ready).