A Community and Forum For Aquaponic Gardeners

back up pump power

i am concerned about losing power and fish dying. i have an inverter and battery charger, if i hooked those up to a marine battery and ran my pump continuously off that, would that be sufficient assuming inverter is rated for the pump start?

0 members like this

Replies to This Discussion

Permalink Reply by Rick Large on May 6, 2013 at 8:38am

I've found that modified sine inverters don't run electric motors very well (usually at a lower efficiency). Keep that in mind if you are using a modified sine inverter. Also, you'll want to ensure your battery charger is smart and won't overcharge the battery and the load is small enough that the charger can keep up, you shouldn't have a problem with charging (assuming both charger and inverter are rated for continuous use). You would see longer battery life with a pure sine inverter that has a battery charger and automatic transfer switch but those can be pricey.

Permalink Reply by marty lininger on May 6, 2013 at 10:51am

thanks Rick, do you think that there would be damage to the motor with a modified sine wave inverter?

Permalink Reply by TCLynx on May 6, 2013 at 2:14pm

Marty,

You may be better off setting up a separate backup pump. I've had issues trying to run an air pump on an inverter from a battery continuously, you really have to make sure all the battery system stuff is well able to handle such use.

I had better luck setting up a fail over relay that would only run the air pump off the inverter/battery if the main power failed and I generally kept the battery on a float or trickle charger.

I made it a point to just run air on the backup for that system at the old house since to get a battery bank that could run everything would have been very costly but the air pump was only 50 watts so I could get a battery that could run that for 2 days for about $110.

as to the inverters, well I learned it pays to spend a bit extra for a good inverter that is way bigger than you think you might need. FYI an inverter that says it's good for 800 watts start up and 400 watts continuous was not big enough to handle that little 50 watt air pump continuous in my hot garage. After replacing the inverter twice I got a better model that was listed as being able to handle higher temperatures as well as being a sine wave inverter.

Now if you are talking a large scale commercial type system, a large whole house type generator might be more appropriate.