Sun Joe 24V Power Cleaner Kit for $45 at Walmart. 68% off

Cobra Kai kicked it's ass 

I bought one of these. Unfortunately the battery is only good for about 10 mins and is not enough for my cleaning needs.
A battery upgrade is $60 plus.

I think you got a defective battery.  My battery lasts me 4-5 fishing trips which are approximately 90-120 minutes (I have not measured time, just an estimate).
Eddie also bought the same model, and he had no battery issues.
You might want to contact the manufacturer for a replacement.

Paul

Looks like the one from walmart says 2.0Ah, maybe certain bundles have larger batteries?

Both Eddie and I own 2.0AH battery bundle.

Paul

That’s weird.   The Lowe’s listing for the exact sun Joe pressure washer with the 2ah battery says that it only lasts for 12 minutes.   I’m really curious how you’re able to get 10x the rated battery life out of your's.   I was ready to order one, but I think that it is legit rated to only last 12 minutes on a single charge. 

https://www.lowes.com/pd/Sun-Joe-24-Volt-350-PSI-Max-0-6-GPM-Cold-Water-Electric-Power-Cleaner-Kit-with-2-0-Ah-Battery-Plus-Charger/5002069821


Edit:  Found a copy of the manual.  On page 7, it specifically says 12 minutes max run time. 

https://files.snowjoe.com/product-manuals/24V-PP350-LTE%20MANUAL_ENG%2001062020-M%20FINAL.pdf

Great catch. 
I think my battery lasts much longer since when I am washing my fishing gears (rod, reels, mirage drive, and bixpy jet), I use garden hose pressure (low pressure).  The only time I use high pressure is when I am washing the kayak.  Just like Bixpy Jet, when you operate at the lowest setting, the battery last 6-7 times longer.  I only carry approximately 3.5 gallons of water to wash my gears and kayak; if it was operating at the max flow rate of 0.55 GPM, I should be running out of water between 6 to 7 minutes.

You can see how I use the unit:

Paul