Some libraries and electric companies have a ‘Kill-a-Watt’ device that you can check out. It’s a device which is like a power strip that can tell you how much power is being used. It will tell you how much is being used at any moment, as well as how much you used over time. If you can get one, you can plug in all your stuff to see how much power it’s using and get an idea of how long it would last with that power station.
Most car batteries are designed for starting and not deep cycling. Of course, ‘car battery’ can mean a lot of different things.
The real Kill-a-Watt sells for $35, and there are competing products available for as little as $14. I bought a Kill-A-Watt many years ago, and it’s been handy for understanding power consumption of household appliances - especially those that run intermittently, like a refrigerator. It tells you not just instantaneous power consumption, but also total energy usage over a given time period. Quite handy.
Should it be fully recharged after use or just up to 85%?
For a backup device like this that’s only used rarely, it’s probably best to have it plugged in 100% of the time. You’ll want it at max capacity for the rare times that you need it. Even if a different charging strategy would extend its life, it would likely end up being too much of a hassle for the benefit. It would be easy to forget to plug it in, and then months later it’s dead when you need it. If you don’t want to have it charging 100% of the time, one strategy would be to plug it into a plug timer that’s only on for an hour or so per day.
You’re more likely to throw the thing away before you deplete the cycles. The difference between optimal battery management and standard management might be the difference between 2000 cycles and 5000 cycles. But 2000 cycles is a power outage a week for 40 years.
Ah ok, good to know!
Yeah. Given the hundred bucks this unit cost, I’d say use it in the way that’s most conveninent for you. Which means keep it stored at 100% and run it down as far as needed during the power outage. All this messing around with 85% to 25% just means it might not be ready when you need it. Run this thing to death and plan on getting another in 5-10 years.
And I’d bet this thing will run your aquarium for a good 24 hours or possibly much more since we know your heater runs only intermittently. I propose you test this out by deliberately running the aquarium on it for at least a few hours to monitor the trend.
It’s not quite that cheap! It’s around $650 on amazon but on sale for $550.
Oh! Somehow I thought I read $100 bucks. I bought a 400Wh unit for about $150 a while back for my CPAP. Sorry about that. My thinking still stands. Use this in the way that’s most efficient for you and understand that it’s product life will still be a decade or more.
If it matters, I suspect a much cheaper unit will still cover you for 24+ hours if you figure that 50w heater is on a 10% duty cycle.
At first I was going to buy the 240 but it did have some bad reviews so I decided I might as well just get the 500. Now I’m glad I did because, based on what people have said here, I can probably have the tank lights on as well. I’m going to test it out when it arrives. It’s supposed to be here sometime between Oct 6-12.
Do you have LED tank lights? They consume a lot less power.
Found a decent cite for the power needs of an aquarium: Aquarium power consumption
Yes. The only problem with having the lights on during an outage is that I can’t cover it with a blanket. Or at least I assume I can’t because I don’t imagine it’s safe to put a blanket over lights. During a prolonged outage in winter the room temperature drops enough to be too much for the heater to keep the temperature up in the tank. So having the heater and sponge filter going and a blanket over top should be enough.
I decided if I was going to go through all the trouble and expense of maintaining the tank during an outage, I should have a bit more life in there as half the time it looks empty so I got this guy yesterday.
Update. I finally got around to testing out the battery. I have both the heater and pump plugged in and it’s pulling 60 watts. I’m going to keep them plugged in for the day and see how long the power lasts.
It went down 10% in an hour.
That tends to make priapism less likely.
Ahem.
Carry on.
then your 518Wh battery is more likely a 100Wh battery …
see how long until it stops … and send it back for a refund…
I think that’s right about what we thought it would be isn’t it? It would last about 10 hours? After 5 hours it was at 57% and I decided that was enough of a test and recharged it.
ohhh … sorry, i MISREAD your post …
I (erroneously) read it as “it went down to 10% in 1 hour” facepalm
5 hours and about 50% charge - you are right on the money here …