Flooded Batteries on Float

I'm well aware of the spec. That's why I said the Iota will operate all day long at 104F. They guarantee it in the spec! It needs to see quite a bit more to trigger thermal shutdown.

Arguments have been lame. One below my dignity to respond.

Can't meta speak for himself?

NinerBikes wrote:


Iota has a working range of 0 to 40C, as listed in their literature. 40C =104F.

Salvo wrote:
What makes you think the Iota quits at 104F? I'll bet it will run all day long at 104F. It may stop at 110F, but definitely not at 104.

Just a few weeks ago I had to turn on the A/C. My thermostat only registers to 99F. It was well above that inside. No problem operating the Iota during that time.

The PD and Parallax 7300 converters also have a thermal shutdown. But they don't trip their thermal limit. Why? You never get max current out of these converters when charging batteries. They never get that hot.

BTW, why doesn't PD or Parallax specify max ambient temperature in their spec?

pnichols wrote:


An Iota cutting out at "only" 104 degrees F is a no-no in my book.

Iota has a working range of 0 to 40C, as listed in their literature. 40C =104F.

Salve wrote:
The PD and Parallax 7300 converters also have a thermal shutdown. But they don't trip their thermal limit. Why? You never get max current out of these converters when charging batteries. They never get that hot.

But that's the real trick, isn't it?: Designing in a desired max current that is still delivered at, say, a 120 deg F or higher thermal limit temperature while keeping itself cool using only air convection.

My 7345 has never "shut down" at any interior coach temperature ... it's fan (unfortunately, instead of air convection) only comes on when I force it to output high currents by turning on a bunch of 12 volt stuff all at once. You don't need battery charging to tax a 7345 heavily up around it's limit. IMHO, the 7345 is a good piece of equipment if you don't need more than ~13.8 volts for anything.

As usual, way off topic, but: Speaking of electrons in motion ... what I'm REALLY fascinated with is the teleporters from Star Trek. Now those are some elevators!

Back on topic: I wonder if the Star Trek ship design kept it's dilithium batteries on float between missions, and if so, how?

What makes you think the Iota quits at 104F? I'll bet it will run all day long at 104F. It may stop at 110F, but definitely not at 104.

Just a few weeks ago I had to turn on the A/C. My thermostat only registers to 99F. It was well above that inside. No problem operating the Iota during that time.

The PD and Parallax 7300 converters also have a thermal shutdown. But they don't trip their thermal limit. Why? You never get max current out of these converters when charging batteries. They never get that hot.

BTW, why doesn't PD or Parallax specify max ambient temperature in their spec?

pnichols wrote:


An Iota cutting out at "only" 104 degrees F is a no-no in my book.

NinerBikes wrote:

mena661 wrote:
My L16's are Trojans not US Battery BTW. People think I spend a lot of time on my batteries. I really don't. There is the odd geeky experiment here and there but they just sit on float most of the time. My crappy Iota converter has made me visit them more often lately but since I got the power supply, that will change back to what it was before. I filled them with water a couple weeks or so ago. Last time I messed with them was back in February after an off grid trip. Honestly, once I have a good SG in the bag, I don't need to mess with them at all. I only need to make sure the converter (now power supply) is still working. When I first got them I was out at the RV a lot but once I figured out how they work (charging, hydrometer checking etc), time spent is drastically reduced. About all I do know is make sure the charging source is still working.

And, for those that are 100%er's, or who care, maybe they're anal, this is the goal. Hang around here, listen to the charger engineer, the battery failure engineer consultant, throw in a few handfuls of Solar Panel designers that are finally satisfied with their solar systems with a bit of fine tuning... this should be the goal... Figuring out, by trial and error, what works for YOU.

I would be remiss here in the Tech section to not also mention the myriad of extremely intelligent EE's that grace us with their professional experiences and wisdom through the years. DSchmidt, a couple of EE' I seem to recall from MI, as well as the folks in the field that use the KISS priciple like RJ. As long as you give it some thought before pressing the "send" button, and state your reasons why you have beliefs in observations, it is all very valuable experiences that you may want to or may not want to apply to the design and build of your electrical system.

I may be an anomoly around here, I have always been fascinated by the work performed making electricity, in the form of hydroelectric plants, and the work performed squirting out invisibly from a copper wire... electrons in motion, that electricity can do. Having a best friend in the elevator repair and service business and going on field trips to downtown L.A. to the tall buildings is a constant reminder of the power of electricity as a people mover. If you really want to be blown away, a peek at this is in order... levitation elevators and frictionless linear motor elevators.

Fuji Frictionless Linear Motor Elevators

That's where modern ever-lower-power integrated digital and analog circuits really come into their own. They generate far less heat on their own than their ancestors did so can operate in cramped quarters and not overheat, thus not needing to be auto-shutdown with temperature so soon.

I suspect that with modern power supplies it's more a matter of keeping temperatures down on and around their printed circuit boards - not so much any choke, transformer, or resistor excess heat in the power supply's output stage anymore.

As far as "RV use" is concerned, IMHO, all components of an RV's 12 volt system should be able to continue to operate well up there within both high interior coach and high exterior ambient temperatures - say operate in at least 120 degrees F temperatures at full rated power specifications. And here's the kicker - do this without fans - using air convection only ... for us drycampers that consider electrical energy as precious. BTW and FWIW, "air convection only cooling" also includes the absorption refrigerator's guts along with it's circuit boards.

An Iota cutting out at "only" 104 degrees F is a no-no in my book.

Yes, mena, you are such a spaz. Salvo says so. Popcorn time! :(

Ooooo I gots lots and lots of power supplies that actually are mislabeled. They say "power supply" when they should actually say "heater".

Some of the rinky dink junk has heat sinks inadequate in size for the job. If a 9 cent IC should fail, the jig is up. To China it goes in the hold of a ship for recycling.

Heat sinks and fans consume a lot of my budget in my fooling around with LED's projects. Neither are inexpensive to purchase.

So if a device is designed with a temperature safety shut down, and it shuts down at X load at 35C while a competitor sails happily along at 40C ambient, maybe just maybe the 35C product has components that are 10C warmer than the other product, inside.

With power supplies - I cheat. The big charger of mine for example has several 130 watt 240 volt fans inside to thwart operating in a 35C ambient. An exam with a pyrometer forced me to add forced air induction.

So when a product seemingly shuts down "too early" temperature wise it most certainly may be protecting itself --- from chintzy design engineering.

An RV does not lend itself well to compartment ventilation. An owner voicing opinion from Maine must consider the fact that an owner of a similar product in Henderson, NV faces an entirely different environment.

Ralph Scheidler PhD founder of Sure Power Industries, coached me many decades ago about the art of heat sinking and component cooling. It is a complex area and several factors have to be considered when analyzing or engineering or troubleshooting.

But to reiterate, many products are already shot in the foot when they leave the assembly line. Stupid things. Vertical rather than horizontal orientation of heat sink fins - never mind scrimping on surface radiation area. Faulty design that minimizes convection BTU transfer.

Just My Two Centavos Worth .....:)

It's well known that heat kills. If the Iota has a feature that shuts itself off before it burns up then that certainly is not a crappy converter. It is well engineered and well protected. Didn't he already have some converter(s) that he destroyed?

Converters get installed in tight spaces with little or no ventilation. And then they call them******when they don't work as expected.

I can only chuckle and shake my head.

NinerBikes wrote:

Salvo wrote:
Why is the Iota crappy?

I'm extremely happy with my Iota.

mena661 wrote:
My crappy Iota converter has made me visit them more often lately

Iota's cut out at 104F temp or higher... No Go... Mena lives in a location where the No Go cut off switch works all too frequently for good health of his L-16s.