How to use a car battery with an UPS

[Halyn]

Hi friends,
I am using a APC UPS which has become very old. The condition of battery in my ups is very bad. It was the used UPS, which i basically got. It was my friends ups who bought a new ups for his home and i thought that to keep the old ups with me to use it. But after a few months it started beeping non stop and the battery light was flashing continuously. I thought to replace the battery but it was not really worth because the price was too high to replace it in which I can get a new UPS for the same price. So i thought that why not to fix a car battery in it. Any special car battery which is cheaper and will work well with my ups. I have heard that most of the people they do this tricky thing but it requires a lot of modifications.

[Hardwareman]

I had the same idea to connect my UPS with a car battery, but i also tried in connecting the battery to the main power of the ups. I don't have any idea that how long the battery would give power to the main power of the UPS which in turn would give power to the computer. I believe that using a laptop will help to consume less power. But the method really didn't work. You do't have thought about powering and recharging the battery with the help of dual-power input solar and wind. There are some really good methods using the used parts to make wind and electric generator. If you can implement on the methods than you can refer on the online site which can help you to built your own solar ups.

[T.J.]

First of all car batteries are not meant to cycle it. I think you need an AGM battery which is designed for deep cycle use. The charger in the ups they don't like it. There is even more important thing that is, these units are having inverters which is designed for intermittent use. It Depends on their internal batteries which becomes exhausted under full load conditions in a few minutes. When it does not happens then their components heat to beyond maximum safe operating temperatures and you can be prepared for a better hope the fuse opens. It is not a simple and replace mod, if you value your personal safety.

[deoWo]

I searched for the possible side effects on replacing the APC ES350 UPS battery by a car battery. Those who have found that the risks acceptable which is claimed many hours and even days of stand-by backup power. I decided to select a Marine 665 Starting battery and used it, the battery had a full charge when it is connected. You would be wondering that why it only provides 20 minutes of backup power. Today the power died at my house, so i pluged my laptop into this UPS. After 20 minutes I was running off the Laptop battery alone. After that the APC 550/UPS which gives the powers to my router/modem/ATA begins 1sec interval of beeping. I got that battery and connected to a 400W inverter which gives power to my Laptop; Router; Cable Modem; VOIP ATA, and it still works great, an hours later, I am still working, calling, surfing and the battery still reads at least 12volts which is cheap analog volt-meter.

[Fabian]

I think that a UPS is just essentially a car battery, a chargng circuit
and an invertor which converts 12V DC to 120V AC. Beside this I don't think that I would prfer to use a lead-acid battery in my house. I have also seen the way that the UPS units being tossed around, it is unsafe for commercial producers to manufacture them. The batteries which is used in military fighter jets are muti-cell NiCads, and they can be used to make nice UPS units. I will not recommend any kind of car battery that gives gasses or leak, on the ohter hand the sealed gel acid batteries are safe if treated properly. The alternative would be that you can put a car battery UPS outside, and
run some cables inside your haouse, but I think this could be very cost effective.

[Maxforu]

As you want to connect a car battery with your UPS so i think that you can do it for a very long time but not using the car batteries, marine batteries. You usually need at least 2 for 24VDC, for some of the bigger units which requires 4 for 48VDC. I have used it as i am not using the best standard UPS though but the rack mounts which are designed to run as long as you can which provides battery power, there are fans in the back as well as they have connectors for extra battery packs.