Bent Nail

Hi all, I have a 989 and I have encountered a problem charging a new transmitter battery. The NICAD battery is for a JR 10X, I had the local battery shop replace the existing cell with Sanyo cells (9.6 volts 1100 mAh). I have had success with 4.8 and 6 volt batteries but I am running into a problem with this set. I wanted to form the battery so my initial settings were .30 charge and .40 discharge.

I am connecting directly to the batteries thus bypassing the circuit board. The problem is I can discharge to 1120 mAh but can only charge about 890 to 900 mAh. I have tried 3 or 4 times adjusting the settings; this helped in the beginning but it has not improved.

Below are the last settings.

Common: NICAD, 8 cells, 1100 mAh

Discharge: .40 cutoff 1.10

Charge: .30, cutoff peak 10, trickle .10

Any ideas?

Thanks

John M.

Tim@MRC

Sorry John, I missed this one. Has anything changed with this? Are you still experiencing the same thing? Again, sorry I missed it, please let me know what you find.

Bent Nail

Hi Tim, yes I am still having problems with the 9.6 battery. I have a 6 volt cycling and it appears to be doing fine.

John M.

Tim@MRC

So the 6v cycles fine with similar charge/discharge ratings, but the 9.6 is still exhibiting the same symptoms?

Bent Nail

That is correct, although I have not tried the 9.6 in about 2+ weeks, I am in the process of cycling 3 6.0 batteries. the first completed normally and the second appears to be functioning properly.

When the receiver battery is completed I will try the 9.6 again and verify the settings that I posted. Any Ideas?

John M.

Tim@MRC

Have you tried increasing the charge rate to 0.5 amps, have you tried lower it to 0.2 amps?

Tim

Bent Nail

Hi Tim, it was good talking with you at Toledo, putting a face with the e-mail. I took your advice and tried a couple of different settings. The temperature never got above 85 degrees and the room was at 67. Below are the results.

Test 1.

Chg. .70;Cut off peak 12; Dischg. .60; Cut off V 1.00

D1 935Mah D2 1006Mah
C1 998Mah C2 997Mah.

Test 2.

Chg. .40; Cut off peak 12; Dischg. .80; Cut off V 1.00

D1 917Mah D2 976Mah
C1 923Mah C2 919Mah

Test 3.

Chg. .30; Cut off peak 10; Dischg .30 Cut off V 1.00

D1 1109Mah D2 1230Mah
C1 881Mah C2 846Mah.

I think I will go with test 3 since it gave me the best discharge. Admittedly, I cannot figure out why I can take out 1100 mAh and only charge 850 mAh+ As you said the transmitter does not have a high draw so this should be fine.

An interesting problem maybe someone will come up wit a plausible answer.

John M.