Can somone explain WHY positive first when jumping a car battery?

No, because the battery doesn't gas unless it is being charged when fully charged already and that won't be happening with either battery.

Its more complicated than that in reality because you wouldnt leave the top off after you have used some to top up the battery.

But isn't impure enough to matter in reality.

Rod Speed wrote on 1/18/2023 7:52 PM:

For them, it is a logical consequence of hoarding food in a survival mode. What goes in, must come out.

Peter wrote on 1/18/2023 5:39 PM:

Medical research says that enlarged prostate is a direct consequence of male hormone, much like male pattern baldness.

I haven't reached a state that I have problem passing urine but I can sense that the passage is narrowing because it takes longer to empty the bladder.

I have been experimenting with all sorts of herbal hair tonics for more than ten years now. I am not bald yet, but like every man I am thinning at the crown.

Finally I come back to think about dealing with the male hormone, the alleged culprit of male pattern baldness and enlarged prostate. I found out on the internet that soybean and the artificial sweetener "Stevia" have female hormone effect. So I started using Stevia instead of Sucralose, and eating a lot of tofu.

For tofu, I buy from Chinese supermarkets soft tofu in plastic buckets that look like this photo:

You might be able to find soft tofu in small plastic flats of 4, or 6 cubes in normal supermarket but Chinese supermarkets also sell tofu in bucket size plastic containers as shown in the above photo.

My way of eating this tofu is:

Put one cube in a 2 qt batter bowl like this

The steam can escape from the lid so there is no danger of the steam and pressure blowing the lid off in the microwave.

Season with anything you like, but I usually eat it with other food in my meal.

It will take a long time to see results in countering the deleterious effect of male hormone in man's hair and prostate, but I can tell than I have less sex drive after two months of using Stevia as sweetener and adding tofu to my diet. Maybe it is working.

They weren't hoarding food in survival mode.

No evidence that more would go in with covid around, so no need for more toilet paper than usual.

Mighty✅ Wannabe✅ <.> wrote

Doesnt explain why an enlarged prostate shows up in old age when the male hormone levels have clearly dropped significantly.

I dont either and am almost into my 80s. Never need to piss at night either.

Don't get any effect like that either.

And my PSA tests are fine.

I haven't bothered and have been visibly balding for more than 50 years now.

I am much balder than that and it is genetic, my dad started to thin in his 30 and ended up quite a bit balder than me.

Don't buy that claim with enlarged prostate for the reason I listed.

You want the spark when disconnecting to be AWAY from the rapidly charging battery.

So: Run the negative from frame to frame, and disconnect at the rescue car first.

-- A host is a host from coast to snipped-for-privacy@panix.com & no one will talk to a host that's close.......................... Unless the host (that isn't close).........................pob 1433 is busy, hung or dead....................................20915-1433

David Lesher snipped-for-privacy@panix.com wrote

There is no hydrogen when the once flat battery is being charged once the engine has started.

Rod Speed wrote on 1/19/2023 3:41 PM:

I real life scenario there is no danger of hydrogen accumulation under the hood because it is too airy inside the engine compartment.

There will be danger of hydrogen accumulation if the lead-acid battery is confined inside a box, like underneath a motorized wheelchair.

Then why do space launch vehicles use burners to ensure that any H2 that pools around the launch site is burned off before launch?

Far more "airy" environment than any automobile engine compartment.

Have you actually seen a rocket launch? The launch rocket itself is a gigantic blowtorch which would have blown away or ignited "any H2 that pools around the launch site". Besides, H2 doesn't "poll around the launch site" because hydrogen is much lighter than air. Any leaked H2 would have risen up into the heavens.

Yes, and a shuttle landing as a guest at Edwards. Note that the SLS uses shuttle main engines.

The person who wrote that is definitely not educated enough to know that hydrogen rises and won't stick around at the base of the rocket. That is the most laughable thing a person can say.

The real reason for the flares shooting at the rocket nozzle is an insurance policy that in case the internal ignition mechanism failed to ignite the hydrogen fuel mixture, the flares will guarantee the hydrogen fuel will be ignited.

Image if the hydrogen fuel mixture failed to ignite internally and there is no flare at the nozzle, the rocket will expel all the hydrogen fuel mixture while sitting on the launch pad. Image how big the fireball that will ensue when it does ignite by static charge or random spark one minute later.

In spades when the hood is opened to allow the positive jumper lead to be connected to the battery post.

Not with modern sealed batterys which have a catalyst that recombines the gases back to water and which have the metal used in the plates which ensure that no hydrogen is produced when they are charged.

Because you get FAR more gaseous hydrogen in that situation.

And the important bit is the fact that the fuel is LIQUID HYDROGEN which can see lots of gaseous hydrogen around the area where the fuel will be ignited if there is any leak at all.

Batteries should never be *quickly* recharged. If you flatten your battery, it is far better to slow charge the battery until it is fully charged at a rate of 4 - 6 amps - depending on battery size. Using the alternator to charge a dead flat battery will result in 35-80 amps being pumped into the battery which will cause overheating and maybe plate buckling - as well as gassing the battery of course. All this tends to shorten the battery life.

Starters can draw 150 - 500 amps of 12 volt DC current. If the negative leads aren't making a good connection, the car bumpers might make the perfect substitute. In the days of metal bumpers, having them weld themselves together is probably not the best outcome. With plastic bumpers, not so much of an *electrical* issue but you'll be scuffing the paint on them.

The negative cable - the last connection to be made - to the dead car should not be made to the battery terminal. Instead, it should be connected to a metal part far removed from the battery. Batteries give off hydrogen gas, especially when they are flat and have been fast charged by the jump cars alternator. The last cable to be connected is the one most likely to create sparks. Best not to be near the potentially gassing battery. Ditto when disconnecting that earth, might spark, again best not near that potentially gassing battery.

If you need to constantly add water, I suggest you check your charge output. Your battery is being overcharged and is gassing the battery. Doesn't do a lot for the longevity of the battery either.

As long as the electrolyte covers the top of the cell plates, all will be well.

Nope. The electrical system of a car is *14 Volts*, not 12V as is commonly believed. You need that voltage to charge a 12 Volt battery at its nominal 12.6 Volts. After charging, the battery will show more than that but it is only a *surface charge* and will quickly dissipate back to 12.6. What people don't realise is that the battery is *only* for starting the engine. Whilst ever the engine is running, the car electrical system is running off the alternator - hence a 14 Volt system. NB, alternators typically output between 13.8 and 14.2 Volts. Any less and the battery may not fully charge, any more and you will get gassing.

Ask yourself what heating water does to its volume and you'll have answered that question.

You shorten the life of your battery.

The "bad" battery will start charging when connected, and there will be no current limiting.

The last time I had a really flat battery, and jumping it didn't work (perhaps the cables weren't heavy enough gauge), I started it with another battery installed (cables semi-tight pushed-on)... then with the alternator keeping it going, I disconnected that battery, and hooked up the flat battery. You could instantly hear the engine bog down from the alternator kicking into high-gear. This was a 1960's car, BTW, with a modern 12v battery. Perhaps this isn't the hottest idea with a new car using expensive electronics, but it works fine on older rigs with a good alternator.