Figure 4-1. Jumper Plug Fabrication

TM 11-6140-224-13&P

Charging with G-76/G Handcranked Generator.

(1) Temperature above 50F. Connect cable from G-76/G to MS3112E-14-55 connector on side of battery. Crank

generator at a speed sufficient to cause 2 ampere indicator light on generator to turn on. Continue cranking at 2 ampere

rate until load suddenly lowers due to opening of pressure switch within the battery. The 3A light on generator will be

extinguished and will not turn on, no matter how fast the generator is cranked. Battery is now fully charged.

(2) Temperature between 30 and 500F. Connect cable from G-76/G to MS3112E-14-55 connector on side of

battery. Crank generator at a speed sufficient to cause 2 ampere indicator light on a generator to turn on. Continue

cranking until G-76/G light goes out and stays out irrespective of charging speed. This will indicate that the battery is fully

charged. At temperatures between 300 and 500F, the load on the generator may not change significantly when the

pressure switch opens because the heater circuit will start drawing power after the battery is fully charged. The G-76/G

does not provide any indication of the current in the heater circuit. The battery may also be charged intermittently as above.

(3) Temperatures below 30F. At temperatures much below 300F intermittent charging is not recommended

because a significant amount of cranking energy will be required to bring the battery to 30F before high rate charging will

start. The suggested procedures for minimum cranking time and effort is as follows:

(a) Start with a battery that is almost completely discharged.

(b) Keep battery in heated area if possible.

(d) Crank at highest sustained rcte possible, use a 2 person cranking to minimize exposure time and resulting

heat loss.

For each 10F the battery is below 30F, 2 minutes of heating at 130 watts, or 3 minutes at 3 ampere (90 watts),

will be required before high rate charging will start. Thus, with the battery at -200F, approximately 10-15 minutes of heating

will be required to bring it to 30F where high rate charging can begin. When high rate charging starts, the current will be

automatically switched by G-76/G generator from the heater to the battery. At this time the 2 ampere light will go on if the

generator is being cranked at a fast enough rate. If the external temperature is low, the heater will switch on for 2 to 3

minute periods every 5 to 10 minutes during the charge, extinguishing the 2 ampere light on the generator while still

maintaining a load on the generator. Total charge time at a 90 watt power input level will vary from about 45 minutes at

200F to 65 minutes at -25F. Figure 4-2 is a typical curve showing the on-off heating characteristics at a fixed cranking

speed.

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