OK, so like I said. I received mine, however its a Sentry Brand... It does have the tire fill valve on it. How are those?

It ran me $117 on amazon. Ill still use it, just haven't had the time to play with it as of yet. Though next purchase will for sure be a Ansul or Amerex.

Buy extinguishers made of metal.  Buy as many as you can afford. Sometimes when you have one, you need four.  That can be a bad day...........

I had a stack of old extinguishers, from dry chem to CO2, some dating over 30 years old.  I blasted them all in the back yard when I updated.  All of them worked, even the plastic Kidde shit that was under recall.

I do have numerous kidde 2lb extinguisher, and two 5 lbs one in truck one in building. Now I will be getting numerous of the 2.5 gal ones... I attempted to use one of the 2 lb ext on a camp fire in back yard and the chem just flew past the fire and up into the air... Was a bit windy that night. Was completely useless...

I also found some navacool sold in 2 ounce container ready for a 2.5 gal tank. $50 for six 2 ounce bottles.
https://www.swfirefightingfoam.com/

Sentry is Ansul's brand name.
The tire type valve is the typical method to pressurize a water extinguisher. Best to do it in one fill up to 100psi, if you do multiple hits of air you'll probably get some water out the valve.

Put a link to this thread in another fire extinguisher thread and read through it and saw this... lithium-ion batteries go into a runaway thermal reaction that generates heat, the flames are more a symptom than the disease. It's not so much a matter of just quenching the flames, but rather cooling the whole thing enough to stop the reaction.

The FAA trains flight attendants to pour water bottles (or other beverages) from the drink cart onto battery fires rather than try to put them out with the small halon extinguishers. The liquid boiling away is what it needs to do to provide cooling, just need enough quantity of liquid to really cool it off, or else keep anything else from catching on fire until it finishes its reaction.

The water mist extinguishers that were made for the ISS have something like 1 liter of water and were tested to put out a laptop computer battery fire.

Great thread.

My only home fire was in the kitchen. The oven element decided to melt down and burn like a cannon fuse, about 1 inch every 10 seconds. The small ABC had no effect. Handfuls of heavy sand from a sandbag had no effect.
My wife said turn off the breaker, which killed the arc that wouldn't die.

Despite working for decades as an industrial electrician and dealing with all manner of electrical fires, my mind went to shit when it was my home at stake. Instant adrenaline dump and brain fart.
Practice and train for your response. I never dreamed such a simple thing could kick my ass for a minute or so.

What does salt, sugar, or high fructose corn syrup do in a fire?
IIRC a saturated salt solution is good to around +5°F.

Something definitely to keep in mind with anything electrical that's on fire, is to kill the power if at all possible. Anytime you have an extra power source putting energy into a fire its going to be that much harder, if not impossible, to extinguish.

Sugar and corn syrup burn, they make a good fuel for oxygen. Salt (NaCl) melts at about 1500 F,  at lower temp (i.e. most wood etc fires) salt would act like sand and block the flow of air to the fire.

So if I fill a water can with distilled or deionized water, I can use it in an electrical fire?

It is not zero risk, but the risk appears to be low with household electric.
https://www.ar15.com/forums/outdoors/Fire_extinguishers/17-669015/#i11435734
Deionized conducts less than distilled which conducts less than tap water.

There are water mist extinguishers that are rated for Class C using deionized water.

Another question
I have a 2 liter Kidde foam fire extinguisher that I bought several years ago.

http://www.firesafetysource.com/product/466620K

It is the size of a 5 lb powder extinguisher, but it is rated 8A 70BC, far higher than the dry powder ones.
It is also rated far higher than the afff foam ones sold in Europe for motor transport.

I have not been able to find another one for sale. Why were they discontinued?
What is the agent inside?
Was it because it's not rated for use on electrical fires? The Europeans don't seem to have an issue with this as the afff ones are common on the tube (subway).

Great! I can fill mine using water from my Zero Water filter that deionizes the water.

This is a european market extinguisher, and their rating system is not the same as the US system, so the numbers are not comparable.

A 2 1/2 gallon water extinguisher with a US 2A rating, is rated 21A under the european system.

A 2 1/2 gallon foam extinguisher has US ratings of 3A 20B; a similar european unit is rated 34A 233B.

The mechanical parts of that extinguisher, other than the nozzle, appear to be the same as an older 5lb Kidde unit which was included in the big Kidde recall, so likely they are discontinued everywhere.

The smallest UL rated foam extinguisher that I know of in the US market is the Amerex 254 which is a 6 liter capacity, so still pretty large. The US extinguisher market is driven by NFPA standards which are often incorporated into local fire codes so are geared very strongly toward businesses needs to meet those codes. The extinguisher market in the US is pretty moribund especially when it comes to meeting the needs of homeowners vs businesses.

If it's a stream type water can I wouldn't. To get the C rating I believe it must be a mist type. While breaking the water path OR using deionized water should protect from shock IN THEORY, it doesn't always work that way. So using mist and deionized water is an added safety precaution.

I would also be cautious of recharging any extinguisher with deionized water expecting non-conductive performance. Deionized water is no longer deionized the instant it is exposed to air. The water absorbs ions from the air. Water distilled in a steam column has similar conductivity of deionized water but water distilled in a dehumidifier is 10 times more conductive. That's a problem when a person will be on the handle of the extinguisher.

I'm not a fire extinguisher expert; but I'm doubtful the pressurized charge in a class C water mist extinguisher is permitted to be plain air. If it is, then the number of available ions in that air charge must be low enough that it doesn't drastically effect conductivity.

OK, so I have my 6 2 oz bottles of Nova cool... The guy I purchased from said in the bottles they last indefinitely, once added to extinguisher not pressurized they will last 30 day. If pressurized extinguisher one year. I did fill my water can the other day and pressurized it to put out a small camp fire the other day... I guess I needed a little more pressure... had like a couple ounces of water left in it.. but worked well.
I used a Ryobi handheld compressor to fill, that worked out well. Need to get new one of those anyway. Good use for that...

Just to follow up on what I started, thanks to everyone for all the input and responses  - especially Gamma762. Very helpful info!

I'm curious on your input on the General brand when talking only about water cans. General went bankrupt in 2001 and was bought by Amerex. Amerex chose not to continue the product line so they lost their UL listing. But some were kept in service through parts stock on-hand at various servicers.

One if the major universities must have decided to get rid of all their General water cans bc my local economy is flooded with them right now. I doubt they're non-working, and there isn't much that can go wrong with a water can. My thought is that w/o a current hydro test and service procedure they couldn't find anybody willing to accept the liability of servicing and certifying them.

For a guy that just wants a few for around the homestead/farm and in the garage is it worth touching a General? I plan to do a little experimenting with at least 1 to make a handheld CAFS and test an idea I have. I already have an Amerex water mist for inside the house and an Amerex water can I got on FB marketplace for $20 (not certified or hydritested but not a big deal to me).

Unless a local dealer has a stash of them, the valve stems for the Generals are unavailable. Eventually they will start leaking. The normal service interval would include replacing the valve stem and main O ring. Few places want to deal with the water extinguishers for compliance and liability reasons.

If I remember right I liked the stream out of the General nozzle better than Amerex, but it's been a long time since I used the General.

Any water extinguisher older than 1971 is potentially unsafe and should be retired and left unpressurized. The old Generals and some others just had the date stamped onto the label and may be hard to find. The shells are supposedly brazed instead of welded which has a greater risk of failure.

Thanks for the info! I appreciate it!