Imax B6 / battery capacity

[Tankbear]

Just got my Imax B6 charger today, but the charger keeps shutting off early and saying fully charged.

Tried NiMH battery at 3800mAh, set charge current at 1.9A but this stopped before an hour.

Then tried standard NiCd 1700mAh battery.
Did discharge at 1A 6v, then charge at 1.7A but this only charged to 1300mAh
Now a know if I charge this battery on my other charger with 1A output that shuts off after 1 3/4 hours which is inline with the capacity.

Am I doing something wrong

[caddyshack]

I don't use this charger..but chargeri use has a timer on it ..has yours if so that may be set too low.

[Tankbear]

I don't use this charger..but chargeri use has a timer on it ..has yours if so that may be set too low.

Yes does have auto shut off but set at two hours so it isn't that.

Played with tanks and discharged a few more batteries and did discharge/recharge cycle again.

NiNH mentioned before stopped at about 1500mAh (although bought this off ebay and even other charger doesn't charge it past half way so suspect mis-sold battery capacity )

NiCd mentioned before managed to get to 1400mAh this time so bit better but still short.

Another HL 1700mAh NiCd battery charged to just over 1600mAh so that one almost there.

Maybe I'm setting the charge current too high? Booklet only says refer to battery manufacturer information which I dont have apart from what's printed on the battery, i.e. type, capacity and voltage.

[caddyshack]

Yes your are right that you can charge at the full amps..ie 5000 mah.. putting 5amps in will get the charge done faster but the heat in the batterys will be high (unless they are a match set, they will Gen less heat). So on a 5000mah ..i tend to charge at 3.5 amps. takes a little longer but the battery suffers less from heat build up.

[Tankbear]

So on a 5000mah ..i tend to charge at 3.5 amps. takes a little longer but the battery suffers less from heat build up.

Thing is I'm not charging at anything like that high. Far enough 1.7A into a 1700mAh battery is fast charging, but 1.9A into 3800mAh isn't high. Plus just tried 2.5A into a 5300mAh battery and it stopped after 20 minutes saying fully charged with a capacity inputted of just over 500mAh and battery wasn't warm either.

Hopefully someone with same charger will come along and call me a dip stick and tell me to change something and all will be fine. Otherwise looks like I've got a dud one.

[caddyshack]

From what i have been reading..for the price you pay for this its not a too bad as a charger unit.. How ever this has come up in many post i have been looking at (Voltage readings somewhat inaccurate). Also it dosn't like a battery that has had a poorly charge cell. So if you have a brand new battery you can try. Then put a multimeter on it to see what you have got.

[Tankbear]

Done some more testing.

Put volt meter on battery as it charged and the display voltage read about 1v over the multimeter. Again battery stopped charging before reaching 1700mAh. Tested voltage at battery terminals at read 7.8v. Not certain if that is correct or not, sure I’ve tested full battery before and got 8.4v?

Then gave battery a good testing in metal tiger and it lasted just over 30 minutes which is probably good since light plastic one is about 40 minutes run time. So maybe I’m over reacting?

[Tankbear]

Using Heng Long NiCd 1700mAh battery.

Settings @
Discharge 1A, 6v Cut off
Charge 1A, Delta peak at 18mV (Default 12mV)
Rest between stages 5 minutes.
3x Discharge/recharge cycles

D1 1024mAh (was a fully charged on another charger over a week ago)
C1 1393mAh

D2 1215mAh
C2 0290mAh

D3 0273mAh
C3 0830mAh

Strange how I got different charge levels each time. Plus did a full discharge to 5.1v (0.85v per cell), came home from work did another full discharge. Then changed at 3.7A, although charger was in auto so capped it at 2A and that went to 1456mAh.

Totally confused now.

[caddyshack]

Why are you charging at 3.7amp on a 1700mah battery unless you are charging a 3700mah battery

[Tankbear]

Why are you charging at 3.7amp on a 1700mah battery unless you are charging a 3700mah battery

Sorry typo, ment 3.4 as double capacity of batery to see the fast charge as manual says between 1 and 2 x capacity. But charger capped it at 2A anyway.