I would also like something that decouples the power from the UPS from the wall.
A lot of UPSs out there ends up injecting a lot of noise into the power. When I plug in my audio amplifiers I end up hearing all the imperfections in the UPS AND wall power.
I would love to have something that gives me a clean AC signal along with the benefit of a power backup.
I am by no means a expert but why not just shift power between two batteries. So when battery A is fully charged then you drain Battery A while charging Battery B. Just keep the power equal between them. When you need to actually drain power from the battery you have the full capacity of a single battery without damaging them from keeping them fully charged all the time
Bat A | Bat B
-----------------
100% | 0%
75% | 25%
50% | 50%
25% | 75%
0% | 100%
Because -
1st- Most batteries don’t have problems staying at 100% their main problem is overcharging and it is mainly with the LiCoO chem. ( the most power packed per kilo ) which when overcharged may explode/catch on fire.
2nd - It is expensive because you have 2 batteries doing the job of one. You can just increase the amount of batteries with 15% and keep them at 80% if you are so worried.
3rd - Cycles of charge/discharge are the main problem with batteries life even for lead acid ones. So this method of keeping things safe is a big waste of money.
however if we ignore all those things the idea was interesting.
Is alot of issues with it but was a idea that came to me so i thought i would suggest. Can never ask stupid questions.
ive always kind of wondered why UPS’s dont use somthing like 18650 batteries, which are used in some laptops and such.
Would be nice to repurpose my cordless drill battery packs that sit around doing nothing also…
I have no idea of anything happening in this thread.
Well some part of me is fuck little ups …tesla powerwall and solar for everyone down the street…Power goes out local power keeps everyone running fine.
But to a UPS for a little PC and a few displays it is all down to the battery tech and how to manage that for long life not be on charge 24/7 till dead.
Even an electric car at home could be a game changer power wise. But sidetracked again. We do need a UPS that is smart and batteries can be flexible.
Did i miss it already…?
Which version are you talking about building?
standby
line interactive
double conversion
hybrid
??
I think it is still being talked out.
I have not thought out my idea entirely but I am thinking modular for starters. Open source software so different style modules can be added in.
I do vote for a nice marine deep cycle battery for a good starter.
Module for cleaning up the AC going into unit.
Module for charging setups for different style batteries.
Module for network ability. This would be for people that need the extreme monitoring.
One thing that might be neat is scriptable events. So when the UPS is at 25% power it can send a shutdown to something to help preserve battery
How much is involved in the circuit to have good clean AC power coming out of a ups? Not an electrical engineer by trade but understand and can fix enough of it to get by.
This is something that is quite a bit over my head. I bought a used APC Smart-UPS 1000 with no batteries for C$20,00, and some new batteries for it for C$70.00. On the back of the unit is a place to plug in a connector for a remote battery. I plan on using the pair of 6 volt batteries in my RV as that’s where I’m living currently. The RV batteries are new and cost me ~C$450.00. They have about 1400 amp/hour capacity. Isn’t this somewhat what Wendell is proposing? Or is it something more advanced? A $200.00 limit doesn’t seem feasible.
APCs are usually 24 volts for the smaller ones, using two 6v for extra power won’t work. Using 4 should work fine though, we’ve definitely hacked apart ups cables and added our own batteries.
What would be really nice is to have an n+1 scale-out setup within the enthusiast budget, size and power capacitty.
I know of commercial 15KVA modules from eaton doing just that, but this is out of the enthutsiast budget and directed to the computer rooms market
Professional grade battery with ten year lifetime are available, from the ups manufacturer, again not in enthusiast budget, although can be financially interresting
Also Batteries are purpose build, either for peak current /power or weight and size (cars drones etc…).
In the similar way the electronic is also usually purpose build. and optimized for the battery cycles
So modular is for me the way to go (with opensource software and firmware)
Actually i think there is an opportunity to build in the UPS the main(s) infrastructure monitoring tool too… no ?
so I got about half way to 2/3rds the way through this tread and kinda hit the wall of rando speculation.
the basic issue with your Battery lasting for a few years and then dying is due solely to the charging profile of the Inverter you are using. Sealed Lead Acid batteries when babied and trickle charge last up to 10 years. the problem with the Current UPC’s out there is that they are built to a price point for commercial sale and shipping. No one is putting a $50 charge circuit and $25 inverter circuit in their UPC’s for sale in the $200 price range as the cost of shipping will eat all your margins.
Lithium Ion Batteries with proper battery management is the future of UPC tech the only issue is you will not hit a commercially viable return if you are looking for a ~$200 retail Price point.
If I was to build a “best UPC” it would be around a arduino or similar programmable controller as the Charger and inverter brains that could then control when the batteries charge based off voltage, amperage and battery temp. with it only ever charging the Lithium batteries to 85%-95% and just building in larger batteries to get back to your desired capacity at that charge level. this is the same Idea that Toyota uses in the Yaris it promotes longer battery life, reduces substantially the fire risk.
$200 was just battery cost btw not retail cost. If it lasts 10 years retail of $500 is probably reasonable assuming something like 1500va capacity
And if the battery its charged and used as per its specs then 10 years is not out of the question.
Yeah at 500 something could probably be made but I am not sure if any battery will still have full life after 10 years of use.