Thursday, July 28, 2011

Assault by Battery

We are at the Myrtle Beach State Park, in Myrtle Beach, South Carolina (map). Wow, is it ever crowded here. The last few times we've been in this area, it has been off-season. Right now we're in the middle of high tourist season, although, oddly, signage at the park does not indicate the bag limit. With things so crowded, we actually made a reservation, uncharacteristic for us. The best I could do on short notice was two nights, and so we will be checking out tomorrow, unless another space opens up.

I had some, uh, reservations about this, since the very first time we came by here, we had barely pulled into the entrance from the road when we stopped short, thinking the trees were too low. Indeed, at that time of the year, there may have been some low-hanging growth that made it look like that, but, in any case, we were too nervous about it to forge ahead, and so we backed out onto the highway and headed south to Huntington Beach, near Murrell's Inlet. We've avoided this place ever since.

In hindsight, that was our very first pass around the country and only our fourth month of living aboard, and we'd already had several problems with low trees in the generally RV-unfriendly east. We did not have nearly the experience we have today with judging tree height or the relative damage potential of low-hanging foliage, and certainly not nearly the experience I have now in backing Odyssey out of bad situations -- we did not want to get a quarter mile down the road only to be stopped in our tracks. Nowadays, backing up a thousand feet just doesn't seem like that big a deal.

I did check the park's web site, and asked around on the boards about low trees. I even called the park, and the ranger who answered said she had never heard anything about low tree problems, and that they got tractor-trailer deliveries all the time. As it turned out, we had no trouble at all, and nothing we passed even seemed low enough to cause us to break a sweat. What a difference nearly seven years makes.

Five of our old batteries out.

We pulled in rather late because we did not leave the parking lot of Carolina Energy, the battery distributor, until almost 7pm. We arrived there shortly after I posted here, between 10:30 and 11:00. I had figured it would take me an hour or so to disconnect all the cables and remove the hold-down brackets, and it would take someone from their warehouse and myself maybe half an hour to get them all out an onto a pallet. Maybe another half hour or so to load the new ones into place, and a couple hours to hook it all back up, so I had figured to be there perhaps four hours or so.

Ha. I should know better by now. For starters, the tie-downs did not come quietly. The nuts are so close to the walls that neither a socket nor even a box-end wrench would fit them, and it took forever to loosen them with an open-end, one sixth of a turn at a time. Then I discovered that two of the cables were attached to a pair of terminals that I simply could not reach with all the batteries in place, so they would have to come out in stages.

Some of the cables and tie-down hardware. Yes, that's my foot sticking out of the tunnel.

The biggest issue, though, was that two of the batteries had to be lifted in place about an inch, then rotated, in order to remove them from behind the inverter. Now, these puppies weigh 167 pounds each, and the only access is crouching in the tunnel, over the steering box and between the wheel wells, that leads from the driver compartment to the motorcycle bay. There's barely room to get your hands onto the batteries, let alone lift something that awkward and heavy from that kneeling position. Ultimately I had to lever them up using my Gorilla Bar, then cram large sockets from my socket driver set underneath them.

Eventually I was able to get all eight batteries loose, and Tony, the warehouse manager and lone employee on duty at the shop was kind enough to come out and help me four separate times to remove them. On top of the other issues, the nylon rope handles kept getting caught on the tie-down uprights. One of the handles had to be cut off to get the last battery out.

The inimitable Tony, hauling off an old battery and taking a call at the same time. Some of the trim that had to be removed is on the left.

Getting the new ones in also proved something of a challenge, although it was actually a bit easier since they redesigned the handles. However, this was the part where I really needed the help -- there is just no way one person can boost a battery that heavy up on top of the wheel well while crouched in the tunnel. It took both of us, working from opposite sides, to push each battery up onto the shelf. I sent Tony away between each pair so I could spend some time wiggling them into position, and also getting the impossible-to-reach cables on the back ones. Again, he came out at least four more times to help me get them in.

How I spent my day. Tony is kneeling in the scooter bay behind me.

When I was removing the old batteries, I found another stud terminal post that had pulled right out of the lead. I had this happen when we were at Choo-Choo Garage a couple weeks ago, and so it was no longer all that surprising, but this clearly happened sometime in the last year or so, and we have no idea, really, how long that battery has been "disconnected." Tony tested all the batteries for me, and this one actually tested "good" and at 77% charged, about the same as the other good ones, so the stud was probably touching enough for the battery to be helping at least a little, but with two of these terminals having been damaged, I was now very nervous about tightening the new terminals, especially after Tony told me the number one issue that leads to terminal failure like this is under-tightening the nuts.

Tony had a booklet with the torque specifications. They listed "120 lb/in" or "162 N•m". Now, I don't know what "lb/in" means in regards to torque (it turns out to be a misprint), but 162 netwon-meters is 120 foot-pounds, and I took out my torque wrench an dutifully dialed that number in. Somewhere in the middle of tightening the very first terminal I realized there was no way this could be right -- that's a lot of torque, and I remembered the stud that came right off in my hand when I overtightened it just a little. I stopped and went inside to ask Tony.

After we both scratched our heads for a while he called Trojan, and Stacy the tech rep there said the correct torque was actually 120-180 inch-pounds, which is 10-15 foot-pounds. Quite a difference. She quickly admitted that the metric numbers in the booklet were simply wrong; whoever published them did the conversion from foot-pounds instead of inch-pounds. It does not look like I damaged the terminal, as I realized it pretty early on. But if that stud pops out in the next two months, I'm going to ask Trojan to warranty the battery; I put the rep on notice when we spoke, and she agreed that, yes, Trojan had incorrectly specified the torque in their own published materials.

My torque wrench doesn't actually work at values that low, so I had to hand-tighten everything by feel. I'll be looking for a small wrench that reads in inch-pounds in the next couple weeks so I can re-torque them to spec at some point. In the meantime, I am going to inspect all the terminals every month or so for a while, until I am comfortable that none is going to pull out.

Once all the batteries were back in place, I set about putting on the rest of the cables. Two of the sixteen terminals have three cables each, while most terminals have just two and two of the terminals get only one. When I went to install the two groups of three, which are the penultimate connections to be made in the whole process, I discovered that the studs on these new batteries are just a couple millimeters shorter than the old ones. I simply could not get the flange nuts to engage even a single thread of the studs. I know on the old batteries that they not only engaged, but that the stud post was flush with the top of the nut when it was tightened.

Upside-down flange nut. I had to tighten it with channel-locks.

We could not really get under way until I had all the cables connected and the batteries back on-line, and by this time the shop was closed. That's when I realized that the very part which could help, the stud-adapter clamp for the automotive post, which I had installed during the stud failure at Choo-Choo, was still clamped to the old battery, now locked in the shop. Ultimately I was able to jury-rig the system by flipping two of the flange nuts upside down, which allowed at least a couple of threads to engage. Today I ran out to Wal-Mart and bought a pair of stud adapters, and in the morning I should be able to finish the job correctly.

We're happy to have a working set of batteries again. In addition to Larry from Carolina Energy coming through with a decent price on these, at just $450 a battery plus tax and fees, or 10% off their original quote, Tony was the star of the show. This company does not do drive-up service or installation, and Tony could have just told me to take the batteries over to Camping World or wherever to get help with them. But he went well above and beyond the bounds of good customer service to help me with these, and I could not have done it without him. Today I dropped by the office with a restaurant gift card and a bottle of his favorite beverage as a thank-you.

I mentioned that Tony tested the old batteries for me. He had to fake out the tester, as it did not really have a setting for 8D-AGM, but he found a setting that worked. The tester unsurprisingly found four batteries to be bad and need replacement, numbers 1, 3, 4, and 5. More surprisingly, it found the other four to be "good," three passing as-is and one needing charge. One of the passing batteries was number 6, the one with the broken-off negative stud. I suspect these batteries were actually marginal, but in the end it's irrelevant, because four bad ones meant the whole bank needed replacing -- you don't want to mix brand new batteries with half-used, four-year-old ones. Oddly, there was no rhyme or reason to which ones were bad and which good, although three of the four were in the lower half of the bank.

Odyssey's battery layout.

By the time I got the last cable on and the inverter fired back up, we had been at the shop around eight hours. We ran the generator for most of that time, with a jury-rig bypass in place to keep two of the air conditioners running the whole time. I crammed all the dress panels and the rest of my tools into the tunnel, we loaded up the scooter that had to come out for access, and headed off to the park, arriving here just after 7.

It was all we could do to unload the scooters and go to dinner. Louise found a nice Italian place fairly close by, Angelo's Steaks and Pasta. And then yours truly, Mr. always-up-to-the-wee-hours, fell face down in the bed at 10pm. This morning I was so sore from crouching in the tunnel all day I could hardly move. I made the one trip to Wal-Mart today and otherwise have been inside in the air conditioning licking my wounds -- those batteries kicked my butt. I'll try to finish the project in the morning when it is a bit cooler, and in a few minutes we'll ride over to the beach and jump in the ocean.


  1. Maybe I am glad I only have 6 volt batteries that weigh about 60 lbs each!

    But it is interesting that three of the bad batteries were in the 0 -12 volt bank, but that the 12 -24 volt bank had three good ones left. But that means that you were essentially running on two of the batteries in series as the only path to chassis ground was thru the single remaining good 0 - 12 volt battery. So at best all it could have put out was the 230 amp hours of that single battery.

    I would be tempted to convert all the studs with post converters where they had more than one wire attached. I would think it is much harder to over torque a post clamp, and breaking that bolt off has much smaller ramifications.

    I have learned quite a bit from following this little battery replacement exercise! Thanks for taking us along............ Rod

  2. The records I have from the previous owner of my bus show nine hours of labor when they had the batteries replaced at a shop. It has six 4Ds. I thought the shop ripped them off but I might be wrong after reading your story. Lol


  3. Sean & Louise, just a little note to say THANK YOU for the wonderful gifts that you brought me for helping out. I too felt like a Coach ran over me after we finished installing those beastly batteries. Once again, Thank You for purchasing the batteries from Carolina Energy Dist. and when you pass this way again, please stop in and see us, you have a friend in Myrtle Beach.
    Tony Cook

  4. is there any benefit to rotating batteries periodically given the seemingly unequal "wear" to them?

  5. Wow! That's quite a job! Thanks for sharing the details.

    Out of curiosity: You don't mention any using any material on the battery connections to aid connectivity and prevent corrosion. I do this regularly - in automotive applications - but have learned from your experiences that the RV battery world is entirely different. What is the best accepted practice for completing battery connections like yours?

  6. Lots of comments to answer here.

    @Tony: Thanks so much, again, for helping, it really was above and beyond. Dinner-and-a-drink was really just a small token of how much we appreciated your help. We'll definitely stop in to say hello the next time we are in MB.

    @Rod: It's not as simple as only two batteries in series, because "bad" on the tester can mean lots of things. Some ways a battery can be bad will actually decrease the performance of the good batteries in the bank, and some ways it might still be helping out a little. In our case, I would estimate that the usable capacity of the bank had dropped to about a quarter of nominal. However, even the one "good" battery in the lower half could not, at this age, still be providing a full 230 AH. Note, however, that our Vanner equalizer is bidirectional, so if we took away all the bad batteries altogether, leaving one in the bottom half and three in the top, we'd still get nearly four-battery performance, or 460 AH. So the four bad batteries here were probably doing neither harm nor good, and the four "good" ones were probably down to about half their rated capacity. Give or take.

    With regard to putting adapters on all the terminals, that's really not an option unless I first deliberately break off the studs. With the stud in place, there are a limited number of ways the adapters can be installed at all without either hitting the stud or protruding too close to something grounded for comfort. There are even fewer angles at which the adapters can be installed where the original stud can still be accessed for use or reached by the existing cables. Just putting the two that I had to use in place was a challenge, as I wrote in the next post.

    @Davy: I expect that coaches with easier-to-reach battery bays might require less labor. But removing and reinstalling that many thick cables, and dismounting and remounting that many heavy batteries, is easily a many-hour process, so, no, nine person-hours is not out of the realm of possibility. By the time I was done with this project, I had easily spent 10-11 hours of my own time, and add in at least an hour for the extra set of hands to muscle them into the rack.

    @MELackey: It's important to install the batteries such that the amount of load carried by each battery is nearly the same, as well as the amount of charge it will receive. This means using all equal-length jumpers insofar as possible, and using "opposite corner" connections. Even when you do that perfectly, however, the reality of the battery compartment will probably mean some batteries will be hotter and some will be cooler during charging and heavy use, so there will be "unequal wear" as you called it. Our charger has a single temperature probe, and we've connected it to the hottest battery for safety. So, in short, YES, there is a benefit to "rotating" batteries periodically the same way you'd rotate tires. That said, at 167 lbs each and a dozen hours to yank and reinstall our batteries, we'll just live with the consequences. We do have mostly equal-length cables, except for the pair that crosses the tunnel, and a good equalizer.

    @Phil: I use silicone dielectric grease as well as anti-corrosion pads and red anti-corrosion spray on the chassis batteries, which are conventional flooded (but "maintenance free") models and are in a compartment that is more exposed to the elements.

    These "house" batteries, however, are sealed batteries that do not outgas, so there is no "acid mist" to worry about as with flooded cells, and they are also mounted indoors, behind the driver and passenger seats. So corrosion is simply not an issue in this application, and when we pulled the eight old ones out, there was not a spec of it anywhere. If the house batteries are the flooded type, or any type mounted in a compartment not completely weather-tight and climate controlled, then corrosion is an issue to be addressed.

  7. Sean,

    Would you mind describing your reasons for selecting Trojan over other brands like Deka, Lifeline? Is it primarily a price point if most other things are equal (size, AH, etc.)

  8. @Jim: In this case, it basically came down to price, availability, and terminal configuration.

    I could have gotten better batteries (Fullriver) for the same money but with the wrong kind of terminals, as I described in an earlier post, and by the time you factor in having to have all new cables made to accommodate the terminal difference, it would end up being a net loss. I could also have had Dekas, which are about the same or maybe a tad better than the Trojans, for less money, but only by driving to Miami for them, which would have negated the savings.

    Lifelines are probably the best AGM house battery that money can buy, but they command a 30%-40% premium, and frankly I don't think you get 30%-40% more performance out of them.


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