What “custom-designed QR codes” actually means

They’re still standard QR codes underneath — they encode the same binary data following the QR code specification. But designers or automated tools stylize the visual appearance of the QR code without breaking its scannability by:

✅ Changing colors — instead of black/white, use any color combo.

✅ Rounding edges of modules (the little black squares) for a softer look.

✅ Adding logos or icons in the center — since QR codes include error correction, you can cover ~10–30% of the code area (depending on error correction level) and the QR will still scan.

✅ Custom shapes — adjusting the squares’ shapes to circles, triangles, or even art patterns, but still matching the original data grid.

✅ Background design — overlaying the QR on photos or adding patterns behind or inside the empty areas of the code.

✅ Eye styling — changing the three big squares in the corners (called “eyes”) with custom designs, colors, or patterns.

dont get confused with Wi-Fi: 5G and cellular 5g

18650

comparison of fully charged voltages

✅ Lithium-ion (18650 cells)

• Nominal voltage: 3.6–3.7 V per cell
• Fully charged voltage: 4.20 V per cell
• Fully discharged (safe cutoff): ~2.5–3.0 V per cell

✅ Lithium-polymer (LiPo) cells

• Nominal voltage: also 3.7 V per cell
• Fully charged voltage: 4.20 V per cell
• Fully discharged (safe cutoff): ~3.0 V per cell

🔎 Key takeaway:

• Both lithium-ion and lithium-polymer cells charge to the same maximum voltage: 4.20 V per cell.
• They differ in physical construction (cylindrical vs. pouch) and mechanical properties (rigid vs. flexible), but not in nominal or full charge voltages.

18650 batteries are lithium-ion, not LiPo (lithium polymer). Here’s the key difference:

✅ 18650 cells

• Cylindrical shape (18mm diameter, 65mm length — hence “18650”).
• Almost always lithium-ion chemistry (like LiCoO₂ or NMC), using liquid electrolyte inside a metal can.
• Extremely common in power banks, laptops, e-bikes, etc.

✅ LiPo (lithium-polymer) cells

• Usually come in flat, flexible pouches.
• “Polymer” refers to the gel-like electrolyte.
• Used in drones, RC models, slim phone batteries, etc.

So if your power bank uses 18650 cells inside (which many do, especially high-capacity models like 26800mAh), those cells are lithium-ion, not lithium-polymer.

what does the 26800mAh really mean? Are you looking at battery capacity when you acquire battery banks. The 26800mAh (milliampere-hours) rating on the Riapow Solar Charger Power Bank tells you how much electric charge the battery can store — it’s a measure of its capacity.

Here’s what it means practically:

• 26800mAh = 26.8Ah (amp-hours) at 3.7 volts (the typical voltage of lithium-ion cells).
• This capacity indicates how long it can supply a certain current: for example, it could deliver 1 amp of current for 26.8 hours before needing a recharge (in theory).
• In real use, because phone batteries are often around 3000–4000mAh, a fully charged 26800mAh power bank can recharge a typical smartphone roughly 6–8 times before the power bank itself needs recharging.
• This makes it a high-capacity power bank, well-suited for camping, travel, or extended outdoor use where access to power is limited.

Keep in mind: actual performance depends on conversion losses (from the power bank's 3.7V to your device's 5V USB output) and the efficiency of charging circuits, so you won’t get the exact rated capacity in practice — but it’s a good ballpark.

Would you like a comparison to smaller or larger power banks?

Here’s a detailed explanation of Nylon Filament PA6:

🧵 What is Nylon Filament PA6?

PA6, or Polyamide 6, is a type of nylon — a synthetic polymer belonging to the polyamide family. Nylon PA6 filament is widely used in 3D printing and industrial applications due to its excellent mechanical properties, durability, and resistance to wear. It’s sometimes also called Nylon 6 or Perlon, and it’s produced through the polymerization of caprolactam.

When you see “Nylon Filament PA6” in a spec sheet or product listing, it usually refers to a 3D printing filament or industrial extrusion filament made from pure or modified PA6 resin.

⚙️ Key Technical Properties

• Tensile Strength: 50–80 MPa (good resistance to breaking under tension).
• Elongation at Break: 40–150% (high flexibility compared to more brittle plastics).
• Impact Resistance: Excellent toughness; nylon PA6 absorbs impacts without cracking.
• Melting Point: ~220°C.
• Density: ~1.13 g/cm³.
• Water Absorption: High; PA6 is hygroscopic, meaning it absorbs moisture from the air, which can affect performance if not dried before use.
• Hardness: ~75–85 Shore D.
• Abrasion Resistance: Outstanding — nylon PA6 is commonly used for gears, bushings, and wear parts.

🔥 Heat & Chemical Resistance

• Operating Temperature Range: -40°C to ~100°C continuous, up to ~160°C for short-term exposure.
• Chemical Resistance: Good resistance to oils, greases, fuels, and weak acids/bases; poor resistance to strong acids.
• UV Resistance: Poor — it tends to degrade and become brittle if exposed to direct sunlight for prolonged periods without stabilizers.

🎨 Applications

• 3D Printing: Popular for mechanical parts, functional prototypes, jigs, fixtures, gears, and components requiring strength, impact resistance, or friction resistance.
• Industrial Manufacturing: Used for injection-molded parts in automotive, electrical housings, consumer goods, and textile machinery.
• Engineering Components: Gears, pulleys, bearings, and wear pads.

🖨️ Printing Considerations (for FDM 3D Printing)

• Recommended Print Temperature: 240–260°C.
• Bed Temperature: 70–100°C to reduce warping.
• Enclosure: Highly recommended to avoid warping from temperature fluctuations.
• Moisture Control: PA6 must be dried (e.g., at 70–80°C for 6–12 hours) before printing; otherwise, moisture causes bubbling, poor surface finish, and weak prints.

✅ Advantages

✔️ High strength and durability

✔️ Excellent abrasion resistance

✔️ Good impact and fatigue resistance

✔️ Low coefficient of friction (good for moving parts)

❌ Limitations

❗ High water absorption → needs storage in dry conditions

❗ Can warp significantly without proper print settings

❗ Poor UV resistance (unless UV-stabilized grades are used)

🔎 Summary

Nylon Filament PA6 is a versatile engineering thermoplastic filament that offers a combination of strength, flexibility, and wear resistance ideal for durable, functional parts — but it requires careful handling to avoid moisture-related issues.