OT: Lead Acid Float Charger

"Ralph Mowery" wrote in message news:ZIednS0hRrGY0WHLnZ2dnUU7-L snipped-for-privacy@earthlink.com...

"Jim Thompson" wrote in message news: snipped-for-privacy@4ax.com...

I have read that tires should be ran so often so they get hot and they will last longer as far as the dry rot types of problems.

For about 10 years I had an old beater of a truck that I seldom drove. About every 2 weeks I would drive it to work which was about 15 miles each way. Seemed to solve a lot of problems. =============================================================================

That's the best way. If you start a vehicle up infrequently, you need to keep it running for long enough to get the coolant and oil and the entire exhaust system up to running temps or you will just build up condensation that will slowly cause corrosion damage while it is parked. If you only run it 5-10 minutes you are better off not running it at all. Just idling with no load it would need at least 30 and more likely 60 minutes to get everything toasty warm and dry. Think how many cars you see on the road still dripping water out of the tailpipe when they stop, and they have been running under load for at least five minutes. Also, even if they don't look dry-rotted, tires really start to degrade after about 7-8 years, which is one reason the fed requires date of mfg. on the sidewall. Google will give you lots of articles on this; basically the rubber strength starts dropping off, the rubber gets stiffer, and the rate of heat buildup at speed starts climbing so a blowout is going to happen sooner or later. As for the truck parked in the shade, can't you just put the solar cells somewhere close where they can get sunlight? The current should be low enough that wire loss shouldn't be an issue even for a 100' run. I did some research a couple of months ago and it seems that if the solar cells are rated less than about 15 watts you don't need to worry about overcharging a car sized battery, and that is plenty to keep a charged battery up and happy. More watts and it can charge faster but now you need a charge controller to keep from hurting the battery. I bought a 7.5 watt panel and used it while it was still hitting the 20's at night, but I drive my truck just often enough that I don't know if it made any difference or not. Next winter will tell, when it gets cold and the batteries (diesel so two batteries and lots of cranking current needed) are another year older.

----- Regards, Carl Ijames

Yep, 6 years is what the guy at Discount Tire told me. ...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| San Tan Valley, AZ 85142   Skype: Contacts Only  |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 
              
           The touchstone of liberalism is intolerance

On Wed, 30 Mar 2016 13:07:21 -0700, Jim Thompson Gave us:

Put a battery switch on the thing, and suffer the fact that clock setting regimens are also called for at that point.

Hmmm, I've got plenty of vehicles in a similar situation. I was thinking of a solar thing maybe...

George H.

?

-Lasse

Does it say how much power it uses just sitting there?

I want a solar thing to stick in the wind shield of my truck, Say a bit of direct sun (~1 hour/day) and otherwise diffuse. I have no idea of the numbers... How much does my lead acid loose every day?

George H.

Geesh, how am I going to remember that? It's always a cold winter night, with 2' of snow, and it doesn't start.

George H.

A diode, the right number of solar cells in series, and the right area... or more and some control/ feedback.

And it's gotta work from the dead of winter, to the heat of summer.

George H.

"George Herold" wrote in message news: snipped-for-privacy@googlegroups.com...

On Wednesday, March 30, 2016 at 6:31:44 PM UTC-4, Carl Ijames wrote:

A diode, the right number of solar cells in series, and the right area... or more and some control/ feedback.

And it's gotta work from the dead of winter, to the heat of summer.

George H. ========================================================

Here's the one I bought:

about the same as the one Lasse suggested. Most solar cells sold as "battery chargers" for car batteries contain a Schottky diode to prevent discharge when the sun goes down. Trickle chargers and the smallest battery maintainers range from 0.75 to 1.5 amp max, and the solar lead acid chargers that don't include electronics beyond the diode seem to be under 15 watts so they don't overcharge the battery. 7.5 watts at 12 volts gives 0.6 amps peak, right in the same range, so that's what I went with. Won't charge a dead battery but will slowly charge a moderately discharged one and will keep a charged one at full charge. I played with my ammeter back in Feb on a bright sunny day here in MD, and outside I got about 0.4 amps. On the dash, behind the windshield, the best I got was 0.27 or so, so I'm not worried about overcharging :-). Battery self discharge goes up with temperature, and the panel output should go up in the summer with more sun, so at least they track. The ecm and radio and maybe climate control or other things will draw a few mA to keep their memories going, plus things like the blinking red LED on my dash when the key is out. I also have a 6 A Deltrans Battery Maintainer, and I think I read on their website that internal discharge currents in a car battery were on the order of 10-100 mA (fuzzy memory), so probably of the same order as the key-off loads, so

20-400 mA for 4-6 hours a day should come close to breaking even. I know that my truck started fully charged and was dead after 3 weeks, the longest I ever let it sit. Oh, my solar charger has a red LED on the cigarette lighter adaptor that also draws from the battery when the cells are in the dark. I opened up the adaptor and it has a 1500 ohm resistor in series so that's another 4-8 mA depending on LED drop. Any more and I would have cut the resistor, but I guess it's ok.

----- Regards, Carl Ijames

Well, I can tell you what NOT to purchase. These are all losers: Everyone of them either destroyed themselves playing float charger, killed the battery, or both. The carnage was both messy and expensive. Please note that only one of these was mine. The rest belonged to a mountain top radio site owner that was too cheap to do it right. Incidentally, there were two more chargers that were still working on another site, which were pre-emptively replaced before they blew up.

So, what went wrong:

1. The chargers are not temperature compensated. Never mind the air or building temperature. It's the battery temperature that's important. With the battery sitting on a concrete slab, it's the temperature of the concrete, not the air or building. Either find a charger with a thermistor temp sensor, or put some insulation under the battery.

1. While some of the chargers claimed automatic charge control in 3 stages (bulk, absorption, float), none of them claimed that you could just leave the charger connected to the battery forever. The result was serious overcharging as the float charge did not switch off totally when fully charged. The original idea behind the float cycle was to bring the battery from 95% to 100% SoC. The battery would last longer if it just stayed at 95% charge (despite claims that full charge prevents the build up of sulfate crystals).

2. While all the chargers in the photo had some form of heat sinks on the diodes and regulators, none were large enough or sufficiently vented to be useful if the charger was expected to supply a substantial fraction of the power. This happened after power outages and heavy transmitter use. Get something with big ugly heat sinks and possibly a fan.

1. Fuse? Whazzat? One charger went nuts and produced an impressive hot battery acid fountain. Install a fusible link, fuse, circuit breaker, or relay disconnect.

2. There was no monitoring or telemetry. I didn't even know we had a problem until I arrived to do something else, and found the hot battery acid fountain. Meters, sensors, gauges, and data loggers are a good thing to have.

I also maintained some generators on various mountain tops. Fortunately, I don't do that any more. The problems are similar to starting your pickup. The generators were all 24VDC, used two lead acid batteries in series, but were otherwise similar to the previously mentioned backup batteries.

We used two types of float chargers. The generators use Deltran (except 24VDC): Most everything else uses marine chargers from Statpower/Xantrex: Actually, we bought a pile of Statpower TC10HW, but those are obsolete and no longer sold.

Here's a lousy photo: of a Statpower 12V 40A version that runs this battery pile: However, that's probably overkill for what you need. Here's another lousy photo of a similar Xantrex charger. It's the yellow colored thing near the bottom of the rack: Pretend you don't notice the inadequately thin wires connected to the big blue batteries in the background. (I didn't do that).

What to buy? I dunno. Maybe go to a trailer supply house, or better yet, a marine electronics dealer, and see what they have to offer. If money is really no object, then get something by Xantrex in the 10A or

20A range. This one looks good: Notice the optional remote battery temperature sensor.

Good luck and send my sales commission and consulting fee to the address below.

Drivel: [Q] What's the difference between a bribe and a commission? [A] The bribe is paid in advance. The commission is paid afterwards. Otherwise, they're exactly the same.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

This is what the tow truck drivers use for their jump start cables: They come in a wide variety of current ratings and sizes. I have a pair under my hood for connecting jump start cables. They will come apart if pulled inline, but not if pulled sideways. I know. I've done it both ways.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558

On Wed, 30 Mar 2016 21:10:05 -0700, Jeff Liebermann Gave us:

I think Lead acid is the big loser..

The problem with the newer., more advance stuff is price.

But he could put a bank of motorcycle form factor LiFePo4 batteries in the trunk and nice interconnection circuit.

The car audio punks haven't caught on yet, but these would be better than hauling around another cadillac battery in one's trunk.

They are lighter and last longer and proper charging and maintaining charge rates are easily workable.

Better for the environment too.

Damned expensive though. Probably lay out $1200 for a bank of four to get the Ampere/hour rates you are after.

Then there are the HUGELY expensive military LiPoly jobs.

I had a Battery Tender... total shit. The only good piece of it was one of the cords with alligator clamps on one end, and a plug compatible with my little Harbor Freight solar panel on the other end. The rest went into the trash.

Be aware that the solar panel output reduces with cell temperature, so inside the windshield is a compromise for summer.

My truck sat over five months, while I tracked down some parts. Needless to say, the battery was run down when I finished the repairs. The dumbass charger wouldn't detect the battery, so I fired up the lawn tractor and let it charge the truck's battery.

I have an old Sears charger that's just a 2-tap transformer and rectifier, which has no problems charging a completely dead battery.

Cheers

Phil Hobbs

On Thu, 31 Mar 2016 05:31:08 -0700 (PDT), Phil Hobbs Gave us:

My 4U 60 Volt, 30 Amp DC supply has no problem getting them fired back up either.

The form factor and power requisite is a bit large for a mobile application, however.

Thanks for the nice review Carl. (That one has less 1 star votes than the Wagan..) I assume that there is a diode in the one you bought. The advertising copy on the Amazon page said it was suggested that you unplug the solar panel at night... that seems to defeat the whole purpose, of plug it in and forget it.

George H.

I would have thought by now someone would have come up with a Rube Goldberg inductive (or RF) coupling method >:-} ...Jim Thompson

--
| James E.Thompson                                 |    mens     | 
| Analog Innovations                               |     et      | 
| Analog/Mixed-Signal ASIC's and Discrete Systems  |    manus    | 
| San Tan Valley, AZ 85142   Skype: Contacts Only  |             | 
| Voice:(480)460-2350  Fax: Available upon request |  Brass Rat  | 
| E-mail Icon at http://www.analog-innovations.com |    1962     | 
              
           The touchstone of liberalism is intolerance