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I'm good as long as they don't bring down the station my grid section is fed from ;-) I think that incident knocked 10,000 people off line for a while.

I've wondered about this as well. My scenario is similar. I have an inverter with batteries to be used to power the refrigerator and some other things when the power goes out. With the power out, these devices are plugged into the inverter, not the house wiring. In this scenario, the...

Or your neighbors car ;-)

Mine show 13.49v at 99.6 SOC. Something definitely not working right on the charging side or the batteries have weak cells that prevent the pack from getting to full voltage.

There are a couple types of Valence batteries available on the used market. There's the 40ah, U1-12xp that is typically used on medical carts. Then there is the U27-12xp, which is a 132ah, group 27 sized battery that is commonly used in electric vehicles.

I have a 70 pint/day unit running in my crawlspace. Uses 650 watts running. 100 with just the fan on. It is power hungry. 11.5 KWH over a 24 hour period. Only my AC and electric stove consume more power. My crawl space stays between 50 and 60% humidity. It easily fills a 1.5 gallon bucket...

The 150/300 amp limits are for a single battery. In parallel, those numbers go up with each battery added.

Well, at least is not a 30-06 round... I've seen people use 22 rimfire rounds in older automotive fuse boxes...

The laptop is just for seeing what's going on, the BMS will actually trigger the relays/contactors to cut off the loads for under/over voltage and probably can be used to control when to turn on/off chargers.

Valence does not sell directly to the public and they don't let customers program the BMS anyway, that is supposed to be done by the Valence rep, using their software. I have seen a couple of the high voltage BMS units on eBay, but not one for a 12 - 48 volt system. Even if you can get the BMS...

XT-60s can handle 60 amps continuous, XT-90 supports 90 amps.

In a pinch, just use a car battery charger for a little while and see if the pack voltage starts going up.

I'm running a test right now that matches your scenario. Just battery/Inverter to run a 17 Cubic foot top freezer fridge, a laptop, and charge phones/tablets/18650 cells for flashlights. I have 200 watts of solar, a generator, or grid that can be used to charge the battery. I figure having...

I have one of those... Still works after 40 years

Get a Kilowatt meter, hook it up to the various freezers and log the usage for each item (try to log at least 24 hours for each device) you intend to power off the batteries. Once you add up the usage numbers, you can determine if you have enough battery. How many days without sun are you...

I have a couple on the way to do some testing with, will update here as I figure things out. For a simple system, they may work just fine as they are, but the whole proprietary BMS thing is a real road block for adoption in the second hand market for those who want a bigger system. After going...

Look up Progressive Dynamics, they make LiFePO4 chargers for RVs, for 12 volt, I got their PD9160ALV. As Will asks, battery voltage and charge rate need to be known before more specific recommendations can be made.

Don't think of it as wasted money, consider it a spare, or you can use it with another battery to power something else after the next storm hits. MSW power is better then none at all.

The XP line has internal BMS hardware, but to be fully functional, it needs the external BMS. It can balance internal cells on its own. I think low voltage cutoff also works, but can't be sure on that since the inverter also cuts off around 10 v.

Running the UPS at lower capacity will help, the question is how for how long? The inverters in the UPS units are not designed for long run times, so once you are past a few hours, it's any one's guess as to how long it will run before it over heats. Maybe you could run indefinitely with a...

I've been pondering doing something like this with the goal of being able to monitor (or at least log all the batteries in the bank rather than just one at a time.

One way to find out the battery ID is to open the Valence software, then go to the Battery System Info Tab. I recall there being a scan option there. That's how I found my IDs. Once you have The IDs, then set the Com port and ID accordingly.

I've been looking this sort of this too since the batteries in my Cyberpower PR1500 are going south. Was pondering using a LiFePO4 battery instead of SLA. I have some Headway cells arriving soon that I wanted to at least test with just to see what the UPS charging profile/voltages looked like...

Logging on as administrator isn't enough, you have to run the program as administrator as well. On the com port, have another look at the com window in the Valence software. Click the pull down arrow to see if it shows you another com port. I seem to recall that my device manager showed com3...

I've been playing around with some Headway LiFEPO4 cells in a smaller 12v APC UPS. In a nutshell, yes, it does work. Biggest issue so far is the charging profile doesn't fully charge the batteries. Charging also takes a while but that's to be expected given the UPS thinks it's charging SLA...

They have an internal BMS.

I noticed my cheap battery monitor disagreed with the Valence software on Amp readings. Valence was 1 - 4 amps higher. The monitor SOC was way off. I had a heck of a time even getting it to display anything. I was trying to set 14v as max and 12 as empty. Nothing doing. Eventually got it...

Instead of being at work and browsing solar forums....

look for a 24 volt RV battery charger/converter. These take shore power and output 24 volts to run things in RVs. https://www.batterystuff.com/power-supplies/iota-24v-40-amp-power-converter-battery-charger-dls-27-40.html?gclid=EAIaIQobChMI7M2P_LSw5QIVFaSzCh0PZQ5aEAQYBCABEgI7wvD_BwE I have a...

There's other detailed threads on this topic, in short, yes it can be done, but there are things to consider. One of the big ones is cooling of the inverter in the UPS. They are designed to run for as long as the SLA batteries that come in them can run and not much longer. Adding extra AH may...