AMP Draw Issues

mike-s wrote:

harold1946 wrote:
A fully charged 12 volt battery/battery bank should meter at 12.73 volts when at 100 percent SOC, after 12 hours of rest with no load.

It's not clear where you got that number. Trojan says 12.73 V @ 100 percent SOC. Even the source you cited, Battery University, says 12.65 V. Of course, it will vary a bit depending on the chemistry and construction.

As you stated it depends on the chemistry and construction. Also Trojan does not state when the battery reading was taken. If not after a minimum of 6 hours, preferably 12 hours, the SOC is not regarded as accurate.

harold1946 wrote:
A fully charged 12 volt battery/battery bank should meter at 12.24 volts when at 100 percent SOC, after 12 hours of rest with no load.

It's not clear where you got that number. Trojan says 12.73 V @ 100 percent SOC. Even the source you cited, Battery University, says 12.65 V. Of course, it will vary a bit depending on the chemistry and construction.

Sam Spade wrote:

harold1946 wrote:

Go to batteryuniversity.com and study some more.

It should read 12.24. at 100 percent charge.

And then things just get worse.

Would you care to correct that number so that I don't have to look like the bad guy again ???

Nothing to correct. A fully charged 12 volt battery/battery bank should meter at 12.73 volts when at 100 percent SOC, after 12 hours of rest with no load.
If one looks like a, "bad guy" it more than likely because they are making incorrect statements.
If that reading is not obtained the battery/bank is not fully charged and needs attention.

harold1946 wrote:

Go to batteryuniversity.com and study some more.

It should read 12.24. at 100 percent charge.

And then things just get worse.

Would you care to correct that number so that I don't have to look like the bad guy again ???

Sam Spade wrote:


I'm done.

thank you. try keeping your word.

Sam Spade wrote:

mike-s wrote:

Sam Spade wrote:
The truth is nowhere near to what you and the video is claiming.

Dispute documented facts all you want - the truth is plain to see.

That video does NOT qualify as a "documented fact" and therefore you have provided NONE.

Go to batteryuniversity.com and study some more.
To get an accurate voltage reading the battery should be allowed to rest at least 6 hours, (preferably 12 hours) to gain any accuracy as to the state of charge. It should read 12.73. at 100 percent charge.

mike-s wrote:

Sam Spade wrote:
The truth is nowhere near to what you and the video is claiming.

Dispute documented facts all you want - the truth is plain to see.

That video does NOT qualify as a "documented fact" and therefore you have provided NONE.

Sam Spade wrote:
The truth is nowhere near to what you and the video is claiming.

Dispute documented facts all you want - the truth is plain to see.

mike-s wrote:
Finally, working at Radio Shack for 50 years doesn't make you an expert.

How does AT&T and Bell Labs strike you, Mike ???

And finally......AGM batteries don't gas in the conventional sense.

And even a conventional battery won't gas enough to be significant given the parameters in the video.

IF one has conventional batteries, you should ALWAYS check the electrolyte level about every 90 days, in normal use or on a maintenance charger, even an automatic one.

If you really cared about his, Mike, you would do some serious research about what is likely to happen to large batteries if they are subject to ~15 volts/ .75 amps for a couple of hours a day.

The truth is nowhere near to what you and the video is claiming.

Sam Spade wrote:

mike-s wrote:
Feel free to boil your own batteries while in storage. Other than that, you'd do well to follow your own advice and avoid spreading bad info.

750 ma for maybe two or 3 hours a day will NOT " boil your battery".
It just will not.

You're arguing against demonstrable facts with your unsupported and ill-informed opinion. You're simply wrong, but keep digging that hole.

Sure, 15 V for 2-3 hours for ONE DAY may not damage a battery. But, it will definitely cause gassing. But this is also about leaving the panel connected during "long term storage," and 2-3 hours/day of overcharging over the course of weeks or months with no battery watering certainly can damage batteries.

Providing that bad advice, when the potential damage to hundreds of dollars worth of batteries can be easily taken care of with a <$20 controller (or <$5 voltage regulator) just points to bad intent. You're willing to advise that people put their investment in batteries at risk for the sake of trying to win an argument you've already lost.

Edit: I don't really care whether you accept facts or not. I'm only concerned that someone may follow your bad advice and ruin their batteries, when that's easily and inexpensively avoided. Finally, working at Radio Shack for 50 years doesn't make you an expert.