FAQ
TL;DR: For battery use, avoid 230 V LED bulbs with capacitive droppers (“I don’t know how you want to pass DC current through a capacitor?”); their discharge resistors are “several hundred kilohms.” Choose 12–24 V E27/LED filament options instead. [Elektroda, koczis_ws, post #16769475]
Why it matters: This saves you an inverter, reduces losses, and makes a safer, simpler portable light for projects and decor.
Quick Facts
- 4 W LED listed as ~34 W incandescent equivalent; OP bulb claims 32 mA. [Elektroda, kosa_pol, post #16769377]
- 230 V LED bulbs are built for mains AC; battery use needs a DC–AC inverter. [Elektroda, koczis_ws, post #16769393]
- Easier route: pick a 12 V LED lamp and power it from Li‑ion or gel batteries. [Elektroda, elektryku5, post #16769394]
- 24 V E27 AC/DC LED lamps exist and fit standard E27 holders. [Elektroda, 139534, post #16769653]
- “LED filament” style exists; for battery packs, add Li‑ion protection/charging PCB. [Elektroda, elektryku5, post #16769856]
Can I run a 230 V E27 LED bulb directly from batteries?
Not directly. Most 230 V bulbs use a capacitive dropper that needs AC. DC bypasses the reactance, so current control fails. Use a DC–AC inverter or select a low‑voltage E27 lamp instead. As one expert noted, “I don’t know how you want to pass DC current through a capacitor?” [Elektroda, koczis_ws, post #16769475]
What’s the simplest way to make a portable E27 LED light?
Choose a 12 V or 24 V E27 LED lamp rated AC/DC. Pair it with a small 12 V Li‑ion pack or a 12 V SLA/gel battery. This avoids inverters and reduces conversion losses, making the setup compact and efficient. [Elektroda, 139534, post #16769653]
Do I need an inverter for a mains LED bulb on battery?
Yes, if you insist on using a 230 V bulb. A DC–AC inverter creates 230 V AC from your battery, but adds size, cost, and inefficiency. The forum consensus favors switching to a low‑voltage lamp instead. [Elektroda, koczis_ws, post #16769393]
What is an LED filament bulb?
An LED filament bulb uses thin LED strips that mimic vintage filaments and Edison aesthetics. It can be found in E27 forms, and some low‑voltage versions exist, though availability may require sourcing from abroad. For battery packs, include cell protection. [Elektroda, elektryku5, post #16769856]
Is powering a 230 V LED bulb from batteries a bad idea?
It’s inefficient and bulky due to the required inverter. An experienced member summarized it bluntly: powering a 230 V lamp from a battery is pointless compared with using a low‑voltage lamp. [Elektroda, kortyleski, post #16769484]
How do I build a small 12 V battery light with an E27 bulb?
- Buy a 12 V E27 LED bulb rated for DC.
- Connect it to a 12 V Li‑ion or gel battery through an E27 holder.
- Add appropriate charging and protection for the chosen battery chemistry. [Elektroda, elektryku5, post #16769394]
What does the 32 mA on my 4 W bulb mean?
The OP reported 32 mA, likely a label or measurement context. Ratings can be confusing on mains bulbs because internal drivers set LED current. Treat such markings cautiously and verify the lamp’s intended voltage before designing power systems. [Elektroda, kosa_pol, post #16769377]
Will a 230 V LED bulb work on DC if I feed the right voltage?
Not reliably. Capacitive droppers expect AC reactance; with DC, the series capacitor blocks, so current path and regulation are wrong. A large parallel bleeder resistor exists but at hundreds of kilohms, it’s unsuitable for powering the lamp. [Elektroda, koczis_ws, post #16769475]
What socket types should I know besides E27?
Low‑voltage capsule LEDs often use G4 pins instead of threaded E27 caps. If you choose a 12 V G4 lamp, you’ll need a matching G4 holder instead of an E27 socket. [Elektroda, 139534, post #16769653]
Are 24 V E27 LED bulbs a good compromise for decor builds?
Yes. 24 V E27 AC/DC bulbs fit standard sockets and simplify battery packs using two 12 V batteries or appropriate 24 V packs. They offer safer wiring than 230 V while keeping the Edison‑style look. [Elektroda, 139534, post #16769653]
Any safety must‑haves for Li‑ion powered LED projects?
Use a protection PCB for over‑charge, over‑discharge, and short protection. Pair it with a charger designed for your pack configuration. “You will also need a protection” best captures the need in DIY lighting projects. [Elektroda, elektryku5, post #16769856]
Is a real incandescent Edison bulb okay on batteries?
It will light, but Edison‑style incandescents run hot and waste energy. They are poor for portable use and can be a burn hazard in enclosed boxes. Consider LED filament for the same look with far less heat. [Elektroda, koczis_ws, post #16769703]
What’s an edge case where a mains LED won’t light on battery?
Bulbs using a pure capacitive dropper may not light at all on DC. The series capacitor blocks DC flow; only the high‑value bleeder exists, which cannot power the LEDs. [Elektroda, koczis_ws, post #16769475]
Why do people recommend 12 V LEDs for portable builds?
They connect directly to common battery chemistries and need minimal electronics. This reduces size, cost, and failure points versus inverters or driver surgery on 230 V bulbs. [Elektroda, elektryku5, post #16769394]
Can I dismantle a 230 V bulb and feed its internal DC nodes?
You could access the rectifier’s DC output, but it’s discouraged. It’s unsafe, risks shock, and the driver may still expect AC front‑end behavior. Choose purpose‑built low‑voltage bulbs. [Elektroda, koczis_ws, post #16769393]
What’s the best decorative approach for a “box with cables” look?
Use an E27 LED filament bulb rated for 12–24 V and an E27 holder. Hide a protected Li‑ion pack and a charge port in the box for safe, rechargeable operation. [Elektroda, elektryku5, post #16769856]
And I do not recommend the real Edison bulb because it gets very hot. 