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Thanks for the compliments on the images, that's almost all from my back suburban yard with a LOT of light pollution. You just have to take a LOT of images and combine them together. They get better by the square root of the number of images. I'm just starting to read about how to build and...

I understood. And I'm saying last night's measurements put me right at about 80% of the 100ah LiFePO4 that are readily available. But my observing kit has grown a lot over the last year. I would like to say I am maxed out, but... well, things happen. So I do not want to plan for 80AH (100ah...

Yeah... hadn't really thought through the poor efficiency of double conversion. Even if it's 500w total and 10% worse efficiency that's about $60/year at our rates. Not a deal killer but I guess it's of questionable value since I do not really think I have ever had anything damaged by power...

So completely ignorant of all this (but trying to learn so thank you), I'm still stuck on the "compression or flexible busbars" part? Postscript: Oh, I think I get it. if not compressed but at fixed distances as they expand, they will put stress on the top connections due to a fixed width...

Thank you, @svetz, for the thoughts. Hobby first: Yes, it can be challenging, but hobbies with no challenge seem rather pointless. You asked to see photos, here are what I have so far (in about 1.5 years): https://www.captivephotons.com/Photography/Astrophotography/ Certainly takes longer...

Thanks, @krby, indeed I am coming to the same conclusion. As I look to do this "right" and have good monitoring (automated, since I run everything in zabbix and/or home assistant) it is really getting expensive. Some old SLA batteries are easier, heck I can probably just take an old UPS and...

With a 20A charger and 10A or so discharge is there a circumstance where that capacity is really needed? Or is the idea "just in case you decide to start your car with it" (which having written that, I guess it might happen)? Let me look at this with fresh eyes, but that size modules fit...

Got it. Thanks.

I apologize I have been ignoring this thread since I got no email notifications and thought it got no responses. Not sure what's up with that, thought I had everything turned on. Anyway.... as to the UPS batteries, I would say on average I'm getting around 3-4 years, and often they fail...

So my best guess right now is I'm around 80ah which is your 80%, so no room for error really. But some simple minded questions: If I have drop in batteries, I assume I need to parallel them when fully charged, not wait for one to run mostly down and parallel? Won't I have a high current...

Wow, that is pretty cheap. This is making me think also if I get a USB version I can probably build a little ESPhome device to record battery status in MQTT; i already have that integrated with the telescope gear for tracking weather, so I could track SOC (or can I with the BMS?) and shut down...

Discovered this thread, and I just signed up. I am not getting any emails either, none. Well, I think there was a verification email to get signed up, I must have gotten that, but nothing since. I have tested the email and it's good (I set up a separate email for every forum in case they are...

If I'm going to build something large, a double conversion one might be better than line interactive, cleaner power. I do have at least one if not two old UPS' around but they are suspect - probably failed batteries but I didn't consider them worth investing in a new battery set. I haven't...

Hi. New here, and I hope it is OK to ask about just batteries and not solar. I do occasional astronomy from dark sites without power. I set up a Group 27 Lead Acid deep cycle battery and for a while it was adequate, but I am reaching the point where my nightly usage is way over what it can...

May I ask about this drawing, any issues or major things I am omitting? This is based on these batteries (160ah x 4): https://www.electriccarpartscompany.com/163ah-calb-batteries-l173f163b And this BMS: https://overkillsolar.com/product/bms-120a-4s-lifepo4/ And drawn roughly to scale. I...

Ah, I am very glad I asked. Though now I am confused. What I read seems to imply I must always compress these rectangular cells or risk delamination (https://www.currentconnected.com/learning-center/lc-stor/llfp-comp/), but you said "or" use flexible bussbars (I was thinking of just some #6 or...

I have a closet full of computer gear with low total load (maybe 400-500w) and several Cyberpower UPS's, that are basically disposable and I have to replace one every year or three. I have been looking at some postings for DIY UPS setups with inverter/charger (or both separately) and battery(s)...

I did a more careful measurement last night of my lower-power telescope setup, and on a relatively dry night (more relative humidity means more power for dew heaters), and got 48ah. Adding in 2 more amps for the larger dew heaters on my larger scope as an estimate I'm at 76AH, which considering...