Wednesday, April 16, 2014

The ABCs of deep cycle battery labels

My father used to muse, "Love doesn't make the world go round, numbers make the world go round." Well, on a long RV trip, a little lovin' ain't bad, but numbers, sad to say, make much of the RV world go round. And especially is this so when it comes to RV batteries. How long you can keep your electrons flowing is a critical factor in RV trips away from utility hookups.

We're often faced with RVers (and others who should know better) spouting off about CCA numbers related to battery capacity. CCA numbers are for "Cold Cranking Amps," and are a measure of the muscle the battery has available for turning over an engine. Repeat after us: "There is no solid relationship between CCA and battery capacity."

We know we'll hear of chorus of, "Ah, you're full of it!" Full of beans, maybe, after the hot dog roast last night. But let's hold the horse for a minute and talk about the REAL figure that explains a battery's ability to do the work most RVer's need – providing juice for lights, water pumps, cell phones, etc. That number is expressed as of amp-hours capacity. Some battery manufacturers use a different term, the "20 hour rating." Simply stated, amp-hour capacity tells you how many amps can be taken from the battery over a 20 hour period before it is completely discharged. For example, a 110 amp-hour rating means you could pull 5.5 amps per hour continuously for 20 hours before the battery would be depleted. How'd we do that? Divide the amp-hour rating (110) by 20 (hours) and the result is 5.5 amps.

A related rating is "reserve capacity." It's a rating of how many minutes a battery can continuously produce 25 amps before complete discharge. By multiplying the reserve capacity minutes by a factor of .65, you'll get an approximation of that battery's amp-hour capacity. We say approximation because 25 amps is a pretty big load. Most RVers won't be using 25 amps, certainly not continuously until discharge, so the reality is, the actual "usable" amp-hour capacity would probably work out a bit higher.

public domain image
But then come those "narsty" little ratings: CCA, CA, and MCA. Ah, the "A" family! CCA is the fractious one. CCA represents the maximum amount of amps that can be produced by a battery in 30 seconds at 0 degrees Fahrenheit. MCA is for "marine cranking amps," similar to CCA, only at 32 degrees. And CA, or "cranking amps" is the same rating as CCA. All three of these characters are useful for comparing batteries you need to start your engine with. BUT for RVers, when considering storage of electricity for use in running lights, pumps, fans, televisions, etcetera, they are USELESS.

Here's where we aren't full of it. Some have tried to advance the idea that you simply divide the CCA number by 6, and viola! The result is an approximate amp-hour capacity figure. But Billy Joe, it just ain't so. Here's a couple of real-world examples. A Yuasa 68MF battery is rated by its manufacturer as a 525 CCA battery. By this "divide by 6" theory, the amp-hour capacity should be 87.5. But in reality, Yuasa says the amp-hour capacity here is but 68 amp-hours. Meanwhile an Optima D34 battery has a much larger CCA rating--870. Divide that by 6, the"predicted" amp-hour capacity is 145, bad sadly, the reality is the rated amp-hour capacity here is even less than the Yuasa. Optima says the D34 is rated for only 55 amp-hours. So in our photo, that huge 1465 CCA might not be worth a hoot for powering your bedside reading light--you just can't tell.

So what gives? Battery plate design and size and other factors simply make a "CCA to amp-hour" comparison an impossible, "apples to oranges" scenario. When shopping for RV "house" batteries, those that will be used as "deep cycle" storage units for operating your coach equipment, stick with amp-hour capacity wherever possible, or gamble a bit with "reserve minutes."

And remember too, discharging a deep cycle battery to the very bottom means you'll get very few discharge-recharge cycles. Bottom line there--expect to buy house batteries far more often. The old rule of thumb for boondockers really does apply: Don't discharge your deep cycle batteries to less than half their capacity before recharging them. In practical terms as we've often said, 12.2 volts (without a load on) is the recharging point for better battery life expectancy.

Wednesday, April 2, 2014

Boondock Arizona -- in the summer?

R&T De Maris photo

Driving south into Quartzsite from Parker, Arizona this week, we did a quick survey of RVs heading north. More than a quarter of all vehicles rushing north were RVs. Apparently they felt April 1 marked the official end of boondocking for Arizona, and we saw plenty of license plates that indicated Montana, Idaho, and Wyoming were parts these folks were headed for. For some, it seems 80 degree weather is just too much to handle.

Still, there are folks who really do love the dry, hot summers. Can you successfully boondock away from shore power and keep cool enough to survive? Altitude is the key: Not all of Arizona is low-down, overheated desert. Some have found the Chiricahua National Monument in south-centeral part of the state an excellent place to beat the heat, along with providing some stellar views. The monument has a developed campground (length restrictions apply, check out the monument website and click on the campground link under "camping") but some RVers stay free in the Coronado National Forest, just outside the monument.

At the other end of the state, near Flagstaff, where the average high temperature in July is 82 degrees, Uncle Sam offers yet more places to boondock. In the Coconino National Forest there are plenty of developed campgrounds (with associated fees), visit the campground website here for more details. However, free camping is allowed in "dispersed" areas. As an example, take exit 326 from Interstate 17. A paved road leads south, and leads to dirt roads through the pines where dispersed camping is allowed at no charge.

Yes, it does take a bit of mind-set to camp out when temperatures push toward the triple degree mark, but it's certainly not impossible. But by heading up-country, even one of the nation's hot-boxes like Arizona can be summer RV friendly.

Tuesday, March 18, 2014

Be critter safe when cooking outdoors


Recovering Vagabond on flickr.com

As winter moves its chilly hand aside, thoughts of camping out begin to take shape. Ah, the warmth of the sun on your back. The smell of steaks cooking on the grill. The nasty cougar getting ready to steal those steaks off the grill . . .Wait a minute! Is it really safe to cook outdoors? Here are some thoughts from seasoned (not with pepper) RVers on the subject.

Clean up! One couple says they've never had trouble with critters – other than bugs – when cooking outdoors. Of course, they always clean up after cooking, so no scents are attractive to passing wildlife.

Goes Double in Bear Country: NEVER leave dirty dishes, food, or pans outside in bear country. You can expect a visit if you fail to do this – either from a hungry bear, or an angry park ranger. 'Tain't fair to any of them, and if there's 'bear lockers' available, avail yourself of them. If the bears try to break and enter for food smells, better they should hit a locker, rather than your RV or toad vehicle.

What about the BBQ? One RVer in Arizona says his barbeque was attacked and tipped over by passing javelinas. Never heard of one? These not-so-cute peccaries, or wild pigs, have some not-so-cute manners. This same RVer was roasting something good and noticed a cougar on the edge of camp – just down wind. You'd think that might be enough to make you swear off the barbee.

One RVer said he didn't have so much trouble with four-legged critters, as ones with wings. Flies took after his unattended, cold, barbeque. He wrapped a big plastic trash bag around it when not in use, and that ended the problem.

Lions, and tigers, and what? Racoons and skunks, that's what. Racoons are cute, but they like running off with stuff, as do squirrels. Skunks are cute – until your nose gets wrapped around them. Again, keep the camp clean. Yellow-jacket wasps can certainly be annoying – or worse. Some folks will put out a wasp catching trap to try and steer them away from camp. Of course, to some, this is not politically correct. Blue Jays, ravens, and crows are all well-known for their camp-robbing abilities. Keep the food locked up and thwart that problem.

Location, location, location: It seems that if critters have found a good source of food once, they'll come back and try it again. When camp cooking in popular, developed campgrounds, you may have more trouble than "dispersed" camping where folks don't regularly cook, and stupidly leave their stuff out.