Battery back-up

Hi, this is my first post and it is seeking info about battery back-ups. I use a Dreamstation and the battery by Philips is way too much money. I recently, finally, bought all I needed to use a deep cycle marine battery, was ready to buy the battery when there were some safety issues raised. like storage, leakage, and frequent charging for safety reasons.
Then I decided to just get a battery back-up, it seems freedom is the one to get, but it comes with a kit, but the kit does not include a specific 12v cord, that has to be purchased separately. More money than the marine battery, and less time on it.

Any real life experiences, or suggestions would be appreciated.
Thanks.

As you know, the DreamStation is a 12 V system, so you have a wide variety of good batteries from which to choose. Please consider a Lithium Iron Phosphate LiFePO4 battery for greatest safety, efficiency and convenience. You may use a normal lead-acid charger with it, provided it does not exceed 14.4 V charge voltage. The premium LiFePO4 batteries have built-in bluetooth for easy monitoring. As with any high current battery system, you will need to be careful with installation and use (fusing, prevention of short circuits and other superior engineering processes). Drama is not your friend.

At the top of the page click on "Advanced Search" then type in Battery Options and start reading. The nice thing about Respironics is they are 12V and their DC power cord is more affordable. goto cpap.com for the good price on the DC cord.
I started using a jump starter some years ago cuz thats what I had. Give it a go