I've recently come into 4x 12V 26Ah batteries and would like to set up a home UPS system. It would be running my internet, wifi, and a arduino Mega and tablet I have set up for home automation. All in all maybe 500W.
Batteries are HZS 12-26. http://www.batteryclerk.com/store/p/67367-Haze-HZS12-26-HZS-12-26-Flag-12V-26Ah-UPS-Battery.html
I have a 1000W 12V inverter I'll use to go to 120V, but I'd like some advice on the right charger from anons who know.
>>1241200
Check this out:
https://www.amazon.com/NOCO-G3500-UltraSafe-Battery-Charger/dp/B004LWVEKS/ref=sr_1_6?ie=UTF8&qid=1504928819&sr=8-6&keywords=12v+charger
>>1241266
Will that thing supply enough power? At 3.5 A thats only putting out 42W, I thought it would need to be rated higher to match the load on it or won't it just be draining the battery's?
>>1241448
That one would be for maintaining the battery state and occasional recharge use, say after a random infrequent power failure.
How are you using the system ?
>>1241450
Basically pic related, power supply would be the battery charger, so load is always drawn off the DC link
>>1241200
Getting a UPS was the best thing I could have ever done for my PC. I'm no longer replacing like 3 HDDs and 5 USB thumbdrives per year now, due to power spikes and 2-second outages.
>>1241200
>internet, wifi, and a arduino Mega and tablet
what's the native voltage for these things?
internet modem - 12v?
wifi router - 12v?
Mega - 5v?
tablet - usb - 5v?
i'd just use a charger for the 12v in parallel and buck convert for the 5v
>>1241200
>>1241200
Don't use the inverter for everything, there are big efficiency losses, especially if you're not running the inverter near full load. Build or buy a voltage regulator and appropriate adapters and you can run your modem, router, and arduino on DC-DC instead of going DC-AC-DC. My router and modem are both 12v and 1 A I think. I just got a voltage converter for my laptop 12v>19.5v. However I didn't realize the voltage ripples so much it made my capacitors buzz, gotta put a filter on it.
>>1241457
Where is the power to run the charger coming from ?
>>1241476
Standard 120V outlet
>>1241467
>>1241471
I had considered this for the tablet and mega but hadn't thought to go straight DC DC for the modem and router, I will look into it though.
>>1241462
This is the direction I am heading I think, power outages every 3 days here and they are not doing my desktop any favours.
Just reading stories of battery fires has got me spooked to get the right charger on there.
>>1241478
> Standard 120V outlet
Ok so normal line power.
When you have these 3 day interruptions how long do they last typically ?
>>1241484
Depends, sometimes a couple hours, sometimes something will fall on a line someplace and you get the short on off cycles as the power companies relays are closing trying to burn it off. It happens often enough to be a pain in the ass
>>1241485
We can assume you want to be running for those couple of hours - not just have enough time to turn everything off ?
>>1241487
Yeah, 104 A/hr should easily float me for a few hours though.
>>1241488
Well, a charger at around 3.5 amps should be able to keep the batteries up IF you use the line power when possible.
But, you are describing a situation where the line power is so bad you want a full time power system buffer for the sensitive electronic apparatus - that is you want the batteries and inverter online at all times.
If this is all correct then, yes you could use a 40A 13.8 volt switching power supply that runs off the 120V line, to simultaneously power the equipment and recharge the battery as needed.
If the switcher and inverter are average 85% efficient then you will lose around 28% of the power to efficiency with this setup.
>>1241478
>battery fires has got me spooked
Not usually a worry with lead acid batteries.
>>1241200
>4x 12V 26Ah
That's about 100Ah or 1200Wh, enough for about an hour (!) at a 500W load. If you want to recharge within a day you need more than 100Ah/24h or at least 5A to cover the losses. A good car battery charger that does trickle charge after full will do. The suggested 3.5A charger will need longer while the 7.2A version would allow you to add another battery or two. At the power level you mentioned I would consider migrating to a 24V system (would need a different inverter though). The advertized battery maintenance mode only works on a single battery (or two in series if 24V) but not with batteries in parallel. Note that all this is _NOT_ the fully automatic UPS system you may be looking for.
>>1241500
>about an hour
* about two hours
>>1241500
>The advertized battery maintenance mode only works on a single battery
It will work on 4 12V batterries in parallel. I don't think it can tell the difference whether it's 4 small batteries or one big 100AH one. As long as all the batteries are in good shape and, preferably the same make, they will be fine.
These small chargers only work if I also buy or build a switching power supply, which was not my intention.
>>1241515
How would you identify the faulty one?
>>1241583
No. If you use the switching power supply it IS the charger. You don't need a separate charger.
>>1241613
In a battery bank, if you suspect one of the
batteries has a problem, you test each one separately.
>>1241492
>use a 40A 13.8 volt switching power supply that runs off the 120V line, to simultaneously power the equipment and recharge the battery as needed
Yes this is what I'm looking to do, not switch between line power and the inverter, it should always be running on the inverter. Will any "smart" 40-50A charger be able to do this without frying my batteries? Or is there something special I need to look for?
>>1241854
>Will any "smart" 40-50A charger be able to do this without frying my batteries?
Maybe.
But it will tend to charge the batteries at a higher than optimal charge rate.
So will a bare high power switcher at the front.
You also still have the efficiency issue either way.
>>1241854
OP do you already have the inverter ?
A cheap 1000W inverter probably won't work for continuous duty like you want even though you are at 50% rated power.
>>1241893
Yeah I already have it, its not in front of me right now but it's some off brand thing I picked up in a discount bin
>>1241895
Post a picture but it won't last 3 months I'll bet.
You need one that costs $300-$500, preferably
sine wave type, for years of reliable service.
BTW what type of budget does this project have ?
>>1241896
I will tommorow when I get up, working nights right now. I was hoping to get away with a charger in the 100-200 dollar range but that may have been overly hopeful.
>>1241898
I would say the inverter is more critical than the charger in terms of how much to spend.
You can find switchers pretty cheap. My basic computer power supply costs @ $70 and provides over 50A of current at 12V on a single rail.
The problem you will have is that without good electronics experience it might be hard to patch everything together so it all works properly.
I mean you're talking about building a complete custom home power system in the .5 kW range which is not necessarily a trivial task.
>>1241200
Check this out OP:
Has a heavy duty sine wave inverter and powerful charger all in one unit.
https://www.amazon.com/dp/B01MS9EI8Q