Strolling Amok

When a Good Battery Goes Bad

These look like a party is going on in my battery tray. Notice the old black rechargeable looking up anxiously, and for good reason.

“Well, I’m disappointed in your performance, frankly. I have to say it. We’ve been together almost two and a half years now, and that isn’t a very long time for a deep-cycle battery. You attracted me with your flashy 210 amp-hours of  capacity, and the price was right at about $75 for each of you. Things went well for awhile, but I noticed that your output was fine for a year and then slowly started dropping off. Now, it’s gotten so that your voltage drops from 12.8 to 12.7 right away after charging, and then with very little load, drops to 12.6. Then when I wake up in the morning, often as not you’re at 12.4, and that just shouldn’t be! How is it that I’m going to be able to stay for more than one or two nights on the road, without you needing a recharge? Does that sound like 210 amp-hours to you?”

“And now these two little AGM deep-cycles, just 55 amp-hours apiece, come along and show just how much you’ve been slacking off. They’re half your rated capacity, and they’re outdoing you! And that’s not the worst of it! They’re older than you, and never had the daily recharges you’ve had. They were bought new three years ago, and then totally ignored. No monthly recharges for them! They sat in storage all that time, deteriorating so badly that their own mother wouldn’t recognize them when they were finally put to use. They were junk, and given away. Then a month on a desulphating battery charger, and look at them now, running rings around you! Two or three nights look do-able. Yes, they’re still a far cry from 210 amp-hours, but you should be ashamed of yourselves! Ashamed!”

Back in the real world, there are no numerical specs as to when a deep-cycle battery has “failed”. They are dump-able when they no longer do the job for you. And that’s what the affordable marine hybrids did, betraying my devoted trust in a little over two years. That’s no bargain, since the common “deep cycle” batteries offered at Walmart and auto parts places are not true deep-cycle batteries. They are really just starting batteries that have been ruggedized to take more discharging abuse. Out the door, each cost around $80. Ultimately, two $125 6V 225Ah Trojan flooded deep-cycles will inhabit the Defiant’s battery tray, once again making multi-day stops possible when the solar panels are not deployed.

But since this year’s repair costs to the Ford have been breathtaking, I’ll be making do for awhile with the two Optima 12V 55Ah Yellow-Tops that I came across and restored via desulphation, the killer of batteries. I ought to be able to get another year out of them, not when they fail, but when their capacity has dropped to that pathetic place where my folded hybrids are now.

Optimas are a strange breed of deep-cycle batteries, being a type of AGM with their plates curled into rolls. They are spectacularly expensive for any given capacity, making normal AGM batteries look cheap. But they are built to survive a narrow yet popular niche – underhood use in off-road camping. When you have a Jeep, FJ or Land Rover and do true exploration camping in the outback instead of RVing, the goal is to avoid the weight and complications of battery packs, generators, and solar. You want to keep the crapola to a minimum, and use your vehicle’s starting battery for overnight power – most often for keeping a 12V electric fridge rolling. Automotive starting batteries won’t survive such discharging, and yet most deep-cycle batteries will not do well with the very high draw of an engine starter. Quality AGMs are an exception. And cheap Walmart hybrids are an exception too, but don’t straddle that line for very long.

High underhood temperatures are very tough on all batteries, and Optima rates the model I have as good for somewhere around just 300 cycles, which is not much at all. But that rating is underhood. Out in ambient air, actual lifespan goes way up. Optimas come with starter battery terminal posts that are meant for conventional underhood clamps, so adapters are needed to press them into duty for RV use. Once that’s done, they become RV-style AGM’s, albeit weird ones. These particular ones have never seen underhood temperatures, which is good. Then again, they’ve never seen a single maintenance charge in all that time, which is bad. Desulphating does not a new battery make. So we’ll see how things pan out in the longer run.

In the picture at the start of this post, you may have noticed some little blue tags on the spaghetti tangle of wires. These are simply pieces of painter’s tape that I’ve marked with the particular battery and terminal polarity each came off of, so that I don’t screw up the hookup of the new batteries. Example: “B+”. Notice that very few of the wires have the common red or black color coding. I’m a little more prone to confusion these days, which is no new thing, but simply a half-tick more in degree, and cross-wiring the various accoutrements and sensors in the Defiant just does not appeal. And, I’m really not into re-guessing which wire runs to what. I don’t care. I just want to know what the connector should hook up to. I was also very careful about letting any of the many dangling terminals touch anything for fear of creating a momentary short during hook-up. I even threw a bit of tape over some terminals that might pose a problem while I was hefting batteries back and forth, disturbing the wires. Final result: a pretty quick changeover free of mystery and error. I recommend tagging wires, however tacky it may look. It works great.

You may also notice the wood that the batteries are resting on. The angle iron battery trays are designed for one battery size, and anything else can shift to fall through. So, I sawed some one-by boards to fit because the price was right, but they are just a little too thick for comfort. The end ledges are still there, but I’ll need to strap the batteries down for piece of mind on the road. That’s my next quest. Straps. I’ve used long cable ties previously, but they don’t hold up long in the sun exposure.