difference betwen 3 and 4 contact HT1000 chargers?

cracked · Post by **cracked** » Wed Dec 19, 2001 11:27 am

i'm looking at two NTN1171A chargers here (both have the same model number). one has three charging contacts, while the other has four. ht1000 batteries have four contacts. i've been using one of the 3-contact chargers with no problems. any ideas why this other charger has four contacts? looks like it has an extra 5-volt regulator inside. both have considerably different board designs inside, but contact pads in the same places.

motrad1 · Post by **motrad1** » Wed Dec 19, 2001 11:46 am

one is a standard charger the 4 pin model is a charger analyzer

cracked · Post by **cracked** » Wed Dec 19, 2001 12:11 pm

On 2001-12-19 14:46, motrad1 wrote:
one is a standard charger the 4 pin model is a charger analyzer

what exactly is the difference? they both have only "charging" and "complete" indicators.

raymond345 · Post by **raymond345** » Wed Dec 19, 2001 2:50 pm

One is called the smart charger and looks at the charging after 80% very closely to
get max. life out of batteries.

cracked · Post by **cracked** » Wed Dec 19, 2001 6:43 pm

On 2001-12-19 17:50, raymond345 wrote:
One is called the smart charger and looks at the charging after 80% very closely to
get max. life out of batteries.

and both chargers have the same part number???

Will · Post by **Will** » Thu Dec 20, 2001 5:42 pm

This charger is NOT smart, it still looks at battery tempature as an indicator of how much charge. The newer chargers have only three contacts, one is +, one neg, and the third one is battery tempature sens. The fourth contact on the battery is a resistor that the charger used to tell what the mahr rating of the battery is, ie; 1200 mahr or 1500mahr.
Some even newer chargers use two contacts and sense the batteries delta voltage to determine charge status.