Do you mean a portable Android charger (power bank)? Below is a short buying guide plus clear picks for different needs (daily pocket carry, travel, laptop/power users, and magnetic/wireless). I’ve listed why each pick is good and included authoritative references.

Quick buying guide — what to prioritize

• Connector and fast-charge support: choose USB‑C with Power Delivery (PD); PD 3.1 supports higher voltages/wattages (up to 140W/240W on newer specs) for much faster charging and laptop support. (usb.org)
• Capacity vs portability: 5,000–10,000 mAh = pocketable (1 full phone charge or ~1–2); 20,000 mAh = travel/day‑or‑two (2–4 phone charges); 24,000+ mAh = laptop-capable heavy use but heavier. (mAh → Wh conversion matters for airline rules; see below). (engadget.com)
• Output wattage matters more than raw mAh for fast charging — look for 20–30W for phones, 65–140W if you want to charge a laptop. (usb.org)
• Built‑in cables vs separate: built‑in USB‑C cables are convenient if you don’t want to carry one, but check how durable they are. (belkin.com)
• Wireless/magnetic banks: convenient for some phones, but magnetic/Wi‑Fi alignment standards are largely Apple-focused — many Android phones won’t get MagSafe‑style magnetic wireless speeds. For Android, prioritize wired USB‑C PD. (ugreen.com)
• Airline rules: power banks must be carried in carry‑on. Batteries 0–100 Wh are allowed; 101–160 Wh require airline approval; >160 Wh are forbidden. Check your airline before flying. (faa.gov)

Top picks by use-case

• Best pocket / daily carry (very small, cable included option)

  • Anker Nano / small 5–10K power banks — very portable and fast enough for a quick topup; good balance of size and speed for Android phones. (Good compact picks listed in recent portable-charger guides). (engadget.com)

• Best everyday travel / mid-capacity (convenient, multi-charge)

  • Belkin BoostCharge Power Bank 20K with integrated USB‑C cable — 20,000 mAh, built‑in cable, multiple ports (good travel convenience). (belkin.com)

• Best magnetic / wireless option (if you want wireless or a magnetic stand)

  • UGREEN magnetic 10,000mAh / Uno Magnetic — solid wireless + USB‑C PD option; note magnetic wireless alignment and higher Qi speeds are typically optimized for iPhones (Android won’t get the same magnetic wireless benefits). For Android, use wired USB‑C PD for best speeds. (ugreen.com)

• Best high‑capacity & laptop‑capable (power users)

  • Anker 737 (PowerCore 24K / 140W) — 24,000 mAh class with high PD output (enough to fast‑charge laptops and multiple devices). Good real‑world performance but heavier — a top pick if you need desktop‑style power on the go. (anker.com)

What to watch for (practical tips)

• Check the label for Wh (watt‑hours) or calculate Wh = (mAh / 1000) × voltage (typically ~3.7V). Airlines inspect Wh for allowance. (faa.gov)
• If you want to charge a laptop, verify the power bank’s PD wattage (65W+ for many ultrabooks, 100W+ for larger laptops). (usb.org)
• Avoid very cheap no‑name banks; look for safety certifications and good user reviews (over‑current/over‑heat protection). Manufacturer pages and established reviewers (TechRadar/Engadget) are good references. (techradar.com)

If you want, I can:

• Narrow picks by budget (under $40, $40–$100, $100+), or
• Give direct current retailer links for any pick above (Amazon/Anker/Belkin/UGREEN), or
• Convert a model’s mAh to Wh to check airline compliance for your upcoming flight.

Which option would you like me to follow next?