I haven't ben on oxygen very long this time. We took a piece of paper and drew a vertical line down the center and started listing pro-and con on either side of the line. we do this with all major purchase. it came out to be $ 2125.00 a couple of hundred less than expiated .Started using it today very happy so far. the battery seams to recharge very quickly. I was impressed with the quality of every thing in the shipment.
This oxygen concentrator comes with a battery. there is also a AC and a DC charger.the two wheel cart is very sturdy. We also bought an extra battery. the machine (on 2.5 le ) will run the machine about 4 hours on the battery only. The 120 v ac charger takes about 4 hour to charge it back up while supplying O2. The case that the machine slips into seams to to be well made, as does the extra pouch for the chargers.
I think they purchased an oxygen concentrator with a battery.
Regards, Don My ride is a 28 foot Class C, 256 watts solar, 556 amp-hours of Telcom jars, 3000 watt Magnum hybrid inverter, Sola Basic Autoformer, Microair Easy Start.