How long does backup power last - for unusual application - any ideas?

[Anonymous user]

I need to use an air purifier in my car for several hours before I drive it in. The purifiers that will work have wattage of 5 to 50 watts. I sent these questions to APC but haven't gotten answer, and I haven't gotten through on the phones yet either.

I'm trying to find out:

1.) How to calculate or estimate the runtime of backup batteries from the info on the packaging. Does anyone have a formula? Such as some number for the product divided by purifier's watts? Most boxes say how long it will run a 15" monitor, but I have no idea how many watts that is and if it includes the computer. And if I figure it out, can i do a straight calculation?

2.) Can I run the backup battery without plugging into the wall & without constant beeps - and can I then recharge it in my house by plugging it when needed? Does this process wear down the batteries recharge capabilities or wear it out quickly - how quickly?

3.) These units have features I don't need. Are there other options that would be better suited? For instance, are there battery backs for camping? Will it tolerate the bumpiness of a car ride?

I know a few people having trouble with the car chemicals in even semi-new cars, so any ideas of how to solve this would be great!!!!!

Message was edited by: turtlecurls

[Anonymous user]

Also, in order to stop the UPS from beeping you would have to attach it to a PC, install the software (dependant upon UPS purchased), and disable the beeping. The UPS, although it can cold-start (starting the UPS onto it's own battery power) is not designed for this application and it will significantly decrease the life of your battery using it in this manner due to constant deep discharges of the battery.

[Anonymous user]

For your application, plug-in AC power inverter that powers off of your vehicle sounds like the best idea. A small 100W one doesn't cost much.

Message was edited by: KVAr

[Anonymous user]

Thanks for the replies!

I finally reached customer service and got some additional information as well. (And lot's of worry that this isn't what these are intended for.)

Ezbutton - The runtime charts are helpful! It appears that basically the calculation is linear - if unit lasts 20 minutes for 400 watts, then it will last 80 mins (4 x 20) for 50 watts - roughly. I'm not sure if the Step-Approximated Sine is going to be a problem. I'll have to see. Probably. Not something I'd thought of.

Grenade - It's good to know how to get rid of the beeps, even if it is extra steps, I wouldn't have thought about installing the software. The recharge/discharge is problem for these units according to customer service too.

KVar - I have an invertor that will handle 45 watts (90 actually). I need to run it before I get in for several hours and don't want to do that to the battery. It is a good solution for while driving. If I had a garage, the whole problem would go away... Actually then I could just leave the windows down all the time, and use the purifier only when driving.

The whole set of thoughts gave me some ideas, and I researched other rechargable batteries. It looks like a jetski battery might be perfect. It's light, 6-7 pounds. Gel based for tossing around and water contact. Intended for repeat recharging. There is one other problem with the ACP ones - they have temperature range that's limited. The jetski ones are only up to 140F and -20F but it's better and I might find one with a wider range. They're cheap too, around $50. So long as my car doesn't develop an identity crisis...and start swimming.

Thanks for the help. I'm finally in a direction that might be a solution...!

[Anonymous user · Accepted solution]

I need to use an air purifier in my car for several hours before I drive it in. The purifiers that will work have wattage of 5 to 50 watts. I sent these questions to APC but haven't gotten answer, and I haven't gotten through on the phones yet either.

I'm trying to find out:

1.) How to calculate or estimate the runtime of backup batteries from the info on the packaging. Does anyone have a formula? Such as some number for the product divided by purifier's watts? Most boxes say how long it will run a 15" monitor, but I have no idea how many watts that is and if it includes the computer. And if I figure it out, can i do a straight calculation?

2.) Can I run the backup battery without plugging into the wall & without constant beeps - and can I then recharge it in my house by plugging it when needed? Does this process wear down the batteries recharge capabilities or wear it out quickly - how quickly?

3.) These units have features I don't need. Are there other options that would be better suited? For instance, are there battery backs for camping? Will it tolerate the bumpiness of a car ride?

I know a few people having trouble with the car chemicals in even semi-new cars, so any ideas of how to solve this would be great!!!!!

Message was edited by: turtlecurls