Portable Power Station 252.7Wh Power House - Model: RP-PB187
https://www.ravpower.com/products/rp-pb187-portable-power-station
The Ravpower RP-PB187 runs 2 of my D90/A90/TA-20 units paired up DAC/AMP for up to 10 hours - varies with audio listening use, or I can run them indefinitely with a passthrough charge from the included AC adapter (2 prong - no ground wire) *or* charging via an up to 60W PD charger throught the the RP-PB187 USB-C PD port - which allows passthrough charging via the USB-C port, as well as delivering PD60W output from that port.
I picked this Ravpower device over others due to the $159 price + pure sine-wave output - vs others in the price range with modified square-wave AC. Ravpower frequently emails site wide and specific product discounts via their newsletter bringing the price down as low as $159 recently - currently at $179 on Amazon / $189 on RAVpower.com. I signed up for their newsletter and waited for about a month for a specific RP-PB187 discount - $80 off = $169. Ravpower increased the discount by $10 just after I purchased, and Ravpower when asked refunded me that additional $10! Very nice people to work with.
It requires some user monitoring to make sure it keeps charging while varying your use. For example if it "catches up" and becomes fully charged it can stop charging and not resume charging after the battery runs down a bit. This can happen when I stop listening for a while without turning off the AC inverter. Minor grump, but it's a lapse in user friendly automated management - you need to monitor manually. The result is after 10+ hours it may run out of power while in use, and you then need to recharge it with the AC inverter disabled for a short while before using it with the DAC/AMP - or plug them back into AC power temporarily.
Other than that if works great for breaking ground loops when used with the iDefender+iSilencer. Oh, and you'll want to get 2 "cheater adapters" as the RP-PB187 doesn't include a ground pin hole for the AC 2 prong sockets:
Commercial Electric 15 Amp Single Outlet Grounding Adapter, Gray Model # U-09 Store SKU # 224676
https://www.homedepot.com/p/Commerc...-Outlet-Grounding-Adapter-Gray-U-09/203456716
YMMV, and if you use those "cheater" plugs with AC directly, be careful! - I don't use them that way at all!! - really!
Here is a
Hobotech review of the Ravpower RP-PB187