trickle (maintenance) battery bank charging question

[cody c]

After searching the web for sometime I decided I was going to build essentially a UPS power system to supply our sump pump. We got flooded last year, but it was the first time our 70 year old house ever had water in the basement apparently: https://forum.ih8mud.com/threads/got-the-boot-mandatory-evac-calgary-flooding.747071/
One of the fella's from the local club has access to surplus batteries, essentially these with a few miles on them:

https://ez-battery.com/shop/northstar-battery/northstar-nsb-110ft-silver-battery/

and using this as a switch:

http://www.amazon.com/dp/B000JJM7ZS/?tag=ihco-20

with this inverter:

http://www.amazon.com/dp/B003R7M6CS/?tag=ihco-20

Now the question is, what kind of trickle or maintenance charger do I need to charge a bank of 3 or 4 of these 12 volt batteries connected in parallel, the charger will need to be left on full time. I was looking at this on amazon as well, but Im not sure if it will handle the job of 3 or 4 batteries full time:

http://www.amazon.com/dp/B000NCOKV0/?tag=ihco-20

Your thoughts?

 

[cody c]

I emailed a company called battery tender, they have a 4 bank charger which they say is fine for the job, and ok to hook up to multiple batteries that are connected in parallel, so i ordered there 4 bank charger.

 

[Tapage]

The one you posted here is then good for 2 separated batteries ..?

 

[cody c]

The one you posted here is then good for 2 separated batteries ..?

They have a 4 bank charger as well which is the one I ordered.

 

[Mrtwooooo]

I have one of these http://batteryminders.com/details.php?prod=12248