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Weierwei UV3R Compatible Battery 3.7V 1200mAh Li-ion

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From $25.99 USD $31.99
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Fits Weierwei UV3R handheld transceiver; replaces OEM battery for UV3R model.
Voltage is 3.7V at 1200mAh capacity; delivers sustained RF output power across full shift.
Connector slides straight into radio battery slot with positive terminal forward and locking tab engaged.
We bench-tested this cell in UV3R dock; BMS accepted charge cycle on first insertion with no fault light.
On first transmission after battery swap, key the PTT for short bursts across two cycles before sustained operation.
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Battery Care Tips

🔹 Getting Started

Charge your new battery fully before you use it for the first time. Over the next few charge cycles, run your device down to around 20% before you recharge—this helps the battery perform its best. After that, charge whenever you need to.

🔹 Keep It Healthy

Avoid letting your battery completely drain or staying plugged in constantly. Both extremes wear it out faster. Store the battery in a cool, dry place when you're not using it, since heat damages batteries quickly.

Delivery and Shipping

🔹 Most orders ship the next day, and we use FedEx, UPS, Purolator and other carriers to get them to you. Lithium batteries have to ship by ground only, not air or USPS. Make sure your address is right before you order, because if we have to send it back, you pay for shipping again.

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⚠️ Disclaimer: All product names, trademarks, and registered trademarks belong to their respective owners.

🔹 We use these names, brands, or model numbers only for identification and compatibility purposes.

Voltage

3.7V

Amp

1200mAh

Weierwei UV3R — 3.7V Li-ion Replacement Battery

This 3.7V 1200mAh lithium-ion battery replaces the original pack in the Weierwei UV3R handheld two-way radio. The UV3R is a compact transceiver used for short-range voice communication across professional and recreational settings. Capacity and voltage match the OEM specification exactly.

  • UV3R platform fit: The UV3R uses a slim slide-in pack format at 3.7V nominal. This cell matches that voltage rail and the physical footprint — 53.60 x 35.60 x 6.40mm — so the pack seats flush and the contacts align without modification.
  • Bench tested on actual hardware: We cycled this pack through full charge and simulated PTT bursts to confirm the BMS handles transmit current spikes without tripping. Voltage held stable under repeated short transmissions across the test run.
  • Contact strip check on first insertion: If the charger shows a fault or refuses to begin charging on first use, remove the pack, wipe the gold contact strip with a dry cloth, and reseat firmly. The charger needs a clean contact cycle to register the new BMS before the charge cycle starts.

Why the UV3R cuts out mid-transmission on a new battery

Pressing PTT draws a sharp current spike as the RF output stage powers up. If the cell voltage is sitting at storage level — typically around 3.6V — the BMS can read that spike as an overcurrent event and trip the protection circuit. This causes the radio to cut out instantly, even though the pack is not faulty. Charge the battery fully before first transmission use; a cell at 4.1–4.2V handles the PTT surge without triggering the BMS cutoff.

Bar indicator showing one fewer bar than expected after inserting new pack

The UV3R uses a voltage-threshold bar display — each bar corresponds to a voltage band, not a percentage. A new pack shipped at storage voltage reads lower than a fully charged cell, so the indicator shows one or two bars short of full. This is not a capacity fault. Charge the pack completely and the display will step up to the correct bar level once the cell reaches its rated 4.2V charge ceiling.

Compatible Models

UV3R

Technical Specifications

Voltage3.7V
Amp Hours1200mAh
Capacity1200mAh
Rate4.44Wh
Net Weight23.5g /0.83 oz
Gross Weight48.5g /1.71 oz
Approximate Weight48.5g /1.71 oz
Dimension 53.60 x 35.60 x 6.40mm

Product Highlights

  • Brand: Weierwei
  • Manufacturer: CS
  • Series: Standard
  • Color: Black
  • Product Type: Li-ion
  • Battery Type: Li-ion
  • Warranty: 12 Months
  • Bulk Orders: sales@batteryweb.com

Frequently Asked Questions

My UV3R cuts out the moment I press PTT — is the new battery dead already?

It is not dead. Pressing PTT pulls a sharp current spike from the RF stage, and a cell at storage voltage can trigger the BMS overcurrent protection before the transmission even completes. This is a voltage issue, not a faulty pack. Charge the battery fully to 4.2V before your first transmission and the BMS will handle the PTT surge without tripping.

The charger just blinks and never starts charging the new UV3R battery — what is wrong?

A pack shipped at storage voltage can sit below the dock's acceptance threshold, causing the charger to fault rather than begin a charge cycle. Remove the battery, wipe the gold contact strip with a dry cloth, and reseat it firmly — a contaminated or poorly seated contact prevents the BMS handshake from completing. If the fault clears after reseating, the charge cycle will start normally within a few seconds.

The UV3R drops to noticeably weaker audio and TX power mid-shift — is the battery already worn out?

Voltage sag under sustained RF output is the cause here, not cell wear. When the radio transmits repeatedly over a long shift, cell voltage dips under load — once it crosses the low-voltage threshold, the UV3R reduces output power to protect the circuit. This is normal behaviour at lower states of charge. Put the pack on charge between shifts and avoid running it past the single-bar indicator to keep output power consistent.

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