Tuesday, October 14, 2014

And let there be light!!

OK, with that whole windshield thing out of the way I was finally able to get back to the dead battery issue.

Back when I thought I would be picking the van, complete with new windshield,  up the same day I dropped her off, I commandeered the chase car and stopped into the local Walmart. There I found out they had exactly zero deep cycle batteries of any group in stock and, though they call this one, which opened just a few months ago, a Super Walmart, it's more like a mini Super Walmart and they have a limited auto section that never stocks deep cycles. (But they can order them for you. . .)

Next it was on to the local NAPA store which, it turned out, had three of the batteries I was looking for right there on the shelf. I left them there expecting to come back that afternoon with the van and give two of them a new home. Well, as you know, it was several days before I had the van, and the old batteries, back in my hands but NAPA still had the same three batteries there waiting for me.

I exchanged the old for the new and found out that, despite what their web site says about having a very limited deep cycle warranty, if I kill the new within the next 12 months I get free replacements and if it takes me up to 36 months to kill them I'll still get a little something back on exchange.

Installing the new batteries was pretty much the reverse of removing the old ones, with a couple exceptions.

You see the little dip switches there on the front of the Trip-Light charger/inverter?? (The red bits to the left of the LED indicators.) Well there was a couple things I wanted to check on, including flipping each of them a couple times to make sure the connections were good and corrosion free. Since the AGM's I removed and and sealed (Maintenance free) lead acid batteries I was installing use the same charge profile, the dip-switch that sets up that that should not have to be changed but I wanted to make sure anyway. (GEL batteries use a different charge profile and can be killed if the wrong one is used, but AGM/lead acid batteries won't receive a full charge with the GEL profile.)

Also, according to the specs for the Trip-Light it should have two options for bulk charge current, 100 amps or 25 amps. 100 amps is way too much charge current for 200 amp-hours of battery so I should be using the 25 amp setting, yet since day one I've noticed that the initial charge current I get out of the thing when first plugging into shore-power with depleted batteries is more like the high 30 amps. It soon drops to 25 or less but I wanted to verify the position of the dip-switch that controls this anyway since charging them too fast is not good for batteries.

Unfortunately that wasn't very easy. I was able to get that photo by holding the camera way down into the small space available in front of the Trip-Light, unfortunately my head is much larger than the camera and trying to get a hand down there at the same time to flip the switches made it even worse! I tried the mirror, flashlight and dental pick thing but my coordination just wasn't up to it, so I ended up removing the mounting screws (And some of them were pretty hard to get at!) and tilting the charger/inverter up on end to get at the dip-switches; which, it turned out, were all right where they belonged in the first place!

With the Trip-Light remounted and that whole little exercise completed, it was a simple matter to drop the batteries into their cases, hook the solar panel back into the charge controller, re-make all the necessary battery connections after thoroughly cleaning the lugs, reinstall the temperature sensor (There's a small piece of silver foil tape there in the middle of the left-hand battery making sure it stays in place.) and button things back up again.

Before making the battery connections I put a liberal coating of GB Ox-Guard on each lug and post. This hadn't been done when the original batteries were installed. This stuff not only helps retard corrosion, but, unlike the more commonly used dialectic grease, also has  conductive properties to ensure a good solid electrical connection that won't waste power by turning it into heat through the resistance of a less than perfect connection. (Dialectic grease also helps prevent corrosion by keeping oxygen away but is actually non-conductive and should never be added until after the electrical connection has been made!)

I didn't actually reinstall the bed until the next morning, just in case.

Once I had the batteries all hooked back up I plugged the van into shore-power and let the Trip-Light top up the charge for a few hours. (It was a cloudy, rainy day and I was only getting a couple amps out of the solar panel.)

I turned the Trip-Light off in the evening and the next morning, before the sun could get at the solar panel and confuse the issue, I went out and checked the battery voltage

 against the calculated charge percentage. Now that was a great sight! Right where it should be for a healthy set of batteries!

OK, actually that voltage is a touch high but I was a bit late that morning and, though the sun wasn't over the horizon yet, it was high enough that the solar panel was ticking over. Not enough to add any charge to the batteries, if that was the case there would be a little arrow over to the right of the 5-bar indicator, but it was ticking over enough to add a few tenths to the battery voltage reading.

In reality a healthy, fully charged lead acid battery that's been resting a couple hours (No significant current in or out.) should read about 12.63 volts.

But anyway, I'm happy and it's on to the next project, fixing the rain sensor on the Fan-tasticVent.

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