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Well that's sufficiently vague as to be not-terribly-useful. I (obviously) have no idea how this works, but responding to a helpful comment saying "well that's one way but might not be a great idea" without any supporting detail doesn't seem particularly beginner-friendly :)

yeah I would love this functionality as well...

So this is fantastic - one of my philosophies (thanks, Dad!) is "buy good tools and you'll never regret them" ... I guess this question in my head was more about "tools" in the sense of crimpers, power supplies, soldering irons, stuff like that... as opposed to any "active" components like the...

As I'm thinking about what I want to end up doing (for me this is a much a science project/learning experience as an actual use case) I realize that it would be super useful to have a large handful of cables, with lugs, of all different lengths and connector/lug sizes. However, I quickly...

I honestly don't remember what the voltage reading was when I installed them. I knew enough to verify that they voltages of the two were the same, but maybe didn't know enough to charge them "fully"? I *think* that the voltages were something like 13.85 and 13.86 -- but I wouldn't swear to the...

So after a year of farting around watching youtube and lurking forums I've sort of decided to do a nerd project and see if I can progress through some combination of "hack an existing UPS for longer runtime where I don't have to replace stupid lead-acid batteries every year" and eventually end...

My use case is something along the lines of: "I want to be able to have a KWh or two available as backup power, with a load that won't exceed more than 400W sustained with peaks of 700W for a couple of seconds." If I really really stretch my brain out, I guess I could see maybe needing to run...

There are several all-in-one inverter/chargers that all look shockingly similar in how they're constructed, wired, the manuals, etc etc etc. If I had to bet they are likely all sourced from the same or a small set of base suppliers and then have some various seasoning applied in terms of things...

So the whole point was to figure out whether or not I was correctly understanding the physics, not whether the application has any actual relevant value. I don't know much, but I know putting two lugs/posts a foot apart makes a lot less sense than putting them 1" apart on a much thicker busbar...

Hmm. This thing is killing me. I have wired up a connector with what I'm pretty sure is the correct pinout. I have a USB<->RS485 converter that I know works, because I can send/receive data from my battery monitor with it. But when I plug this thing into the Valence battery, nothing happens...

I'm in a very similar spot - I'm trying to build something that's bigger and more expandable than a "big UPS" but not ready to drop several grand on a full powerwall-type system. From my limited learning so far.... I don't think there are any (many?) inverters where you can easily change the...

Thanks. Next dumb question: imagine I'm only drawing 6A rather than 20A. How does the load get distributed across what are now two possible sources: the battery and the charger? Dumb question #3: imagine I've got the batteries at half charge, the charger is on mains, AND I've got a 6A load...

In my case I’m talking about bolting lugs to bus bars or lugs to M8 terminals on assembled batteries

So I found this: https://diysolarforum.com/threads/understanding-aio-idle-power-consumption.41017/ Which is somewhat close to what I'm asking but not quite... I see values for "idle power consumption" in the spec sheets of a lot of these inverters/AIO's ... but what isn't clear to me is which...

I've read through this, wow this is a lot of great info. I came across a pair of U27-XP's that I'm planning on using in parallel with an inverter/charger to function as essentially a high-capacity UPS. I'm trying to figure out how much of the "non existent BMS" functionality I actually need to...

I'm working on basically a homebuilt UPS, this is by far the best forum I've been able to find so thanks to everyone who's already helped (and how much stuff I've read already)... I've got a line on some half-used Valence LFP batteries and they're cheap enough to justify playing around with for...

Ok so I'm (sort of?) following that ... but what happens if the charger leaves the absorption voltage too high for too long? Isn't it the case that once you're at the cutoff voltage on the battery side the BMS simply stops accepting charge? Or am I (still!) missing things here? :) And if one of...

Does the forum infrastructure have some way to look at an entire thread at once? I'm particularly interested in the Valence battery superthread at the moment, but the question applies equally to others I've found. It's really cumbersome if I'm looking for certain things to not be able to...

SIGH. So searching for things like "Read all pages of a thread" somehow didn't show me this result, but as soon as I posted it, this popped up. Sorry for the noise... https://diysolarforum.com/threads/possible-to-view-all-pages-of-a-thread-on-one-page-for-printing-archiving.53523/

wouldn't you want to mount to something nonconductive? Did you drill holes and use bolts/nuts or did you have screws that were sufficiently sharp/strong to just run them through the aluminum?

So this thread is great, thanks. My question is what happens if/when you have multiple chargers that are set for different battery types or profiles? One of the chargers I have the manual for has two "AGM" battery settings, "AGM1" is 14.1/13.4v, and "AGM2" is 14.6/13.7v. If I were to wire up...

Yeah I've been wrestling with windows drivers and trying to find the software and all the .NET stuff.

I was thinking about the -3000 as I think I have a line on an old chassis without SLA's in it already. I thought I read that you couldn't just drop in LiFePo's without the charging logic from the UPS screwing things up. Is that not the case? If it's truly drop in, I might just rig up a 2p...

I need some help with the last part... if you can't determine SOC from the resting/open voltage how CAN you determine if these things are charged? The meter I've got is accurate to a hundredth of a volt, so it's hard for me to understand how that's not a valid metric. And if it's NOT a valid...

Cool. If I have to cut off 1/4” of wire every few iterations that‘s way easier than throwing away $4 lugs and however much effort it takes me to get them on there :)

So I totally understand how an AIO inverter/charger/xfer switch works: the internal logic makes sure that none of the electrons try to go the wrong directions at the wrong time ;-) But, if you've got a case where you have a separate inverter and charger, and both of these are wired to the...

Super useful. A couple followups: let's assume the valence batteries are all treated as separate batteries - totally ignore the fact that they have some #additionalValenceMagic that we might use... I'll just ignore that for argument. If they're "just plan normal parallel 12v LFP batteries"...

Don't think anyone has mentioned, but tap off busbars to feed inverter from opposite ends, or otherwise balance current draw. Sorry I'll have to fess up here, I have absolutely no idea what this sentence means...?

I have experience with a few of these baby APC, and from an internal design standpoint they're all pretty much crap. The output power waveform is really bad, most of my newer PC power supplies won't run when on battery. They also will not run well (if at all) if the INPUT waveform isn't pretty...

Oh cool - makes perfect sense now. Thanks.