DID YOU KNOW .. there is an eHam.net Article on how to rebuild the FNB-4A Battery Pack ?
by Jim, KA3EBX http://www.eham.net/articles/2301
The Yaesu NC-15 is the DESK battery charger for the Yaesu Ni-Cad battery packs (FNB-4A being one of these packs).
The Yaesu NC-18 is the WALL charger that connects to the battery through 3.5 mm coaxial connector (bottom of pack).
Yaesu NC-15 Specifications
Input voltage: 100/110/117/200/220/234 VAC, 50/60 Hz.
Battery packs: Yaesu FNB-3, FNB-4 Ni-Cd packs, with or without transceiver
Charge control: Thermal switch inside battery pack (45°C)
Charging times: 1 hr. for FNB-3 at 25°C ambient, quick mode; 1.5 hr. for FNB-4 at 25°C ambient, quick mode
(trickle mode can be used at any time to prevent self-discharge when the pack is not in use)
Charging current: FNB-3 - approx. 630 mA quick, 20 mA trickle; FNB-4 - approx. 650 mA quick, 20 mA trickle
Operating 'temperature range: 10° to 40° C (500 to 104° F)
AC Adapter output voltage: 12.0 ±0.3 VDC
AC Adapter output current: 1.3 A maximum ,
Specifications for the Yaesu Battery Packs used in the NC-15 charger:
FNB-3A – NiCad Battery Pack 10.8 V - 425 mAh FNB-4A – NiCad Battery Pack 12.0 V - 500 mAh
MODS.DK has the Yaesu NC-15 Owner's Manual -- the schematic for NC-15 is on the LAST PAGE.http://www.mods.dk/manual.php?brand=yaesu
One of the 4 fast charger pin contacts has No connection.
That makes sense. You have an FNB-4A battery pack.
That specific pin (no connection) is used ONLY IF you had an FNB-3A pack.
White: cell temperature sensor
Black (short): negative battery pak contact strip
Red: positive battery pak contact strip
Black (long): ?
4 PIN Assignments (from Battery Charger for FNB-4A)
RED - 12 VDC (charge) -- Used with FNB-4A packs ONLY
N/C - 10.8 VDC (charge) -- Used with FNB-3A packs ONLY
WHITE - Charge control -- Thermal switch inside battery pack (45°C rating)
BLACK (short) - Ground
---Are these 2 wires inside the battery pack?
Do they connect to one of the bottom 4 battery pins (charger)?
or do they go to 3.5 mm power receptacle for the NC-18 charger?
BLACK (long) ?? Likely a Ground connection
BLUE ?? Positive connection to the 3.5 mm receptacle??
AC ADAPTER OUTPUT -- Coaxial Connector You need to CHECK with a VOM or DVM for correct wiring !
Inside Pin - Ground -
Sleeve - 12 VDC, 1.3 Amp