Federal pump does not make a dc back up pumps to my knowledge. They are not in the catalogs that I have. I am sorry that I did not answer your question as to “what Make is the best” being a manufacture of these units I think our make is the best and that is just a little slanted. I tried to give some general help in the type of units that are available. Stevens has a 3 yr warrantee model DC3000 and they make one with a 1 yr warrantee. The 3 yr unit is 24V and requires 2 12v batteries for 1 1/2 hrs of continuous operation. The Zoeller Pump Co model 507 & 510 will run 7.5 hrs on one fully charged battery. What you need to compare is , the total amount of water removed on a fully charge battery as provided. (1 or 2 batteries). The pumps would need to be at the same head, and not running on the charger as some people rate their units. The pump will pump less over time do to the battery losing power over time. The Zoeller model 580 & 585 “aquaNOT” has a 3 yr warrantee when a battery is purchased with the unit..
[Edited by Ken Zoeller on 07 September 2001]