alien

Hi Everone I would like to know I have a battery pack a 1200 4 cell sanyo NiCad pack. Anyway I charge it usering my futaba battery charger which says RX 4.8DC 50mA also it says 4.8V/500mAh this is all the output. Anyway As many hrs as I charge the pack the most I get out of it is 4.4 I cant get it to charge the pack to 4.8 I would like to know why. Could it be my charger or could my pack be bad I have even left it on charge up to 16hrs . I even discharged it down. Could the futaba charger charge a 1200 pack or like I said the pack could be bad . Tops I get out of the pack is 4.6. I have a charger that has fast charge timer with 15min on it I was wondering if I could use that for the pack or will those fast chargers be too much for that typ of pack. Can anyone help out there. can post ans here or email me at [email protected] Thank You

planelazy

You should use a 120 mah charger instead. The normal charge rate is 16 hrs so if you chg at 50 mah for 16 it is not going to get charged.I know you are thinking that if you chg for a longer period that it will get charged but i have read many times that that is not the case. Tim.

w.pasman

A 1200 pack as receiver? I think that's pretty low capacity. I would at least use 1700 on a standard (no digital servos) heli.

alien

Hi I do have a digital servo just one for the tail rotor. So what size battery pack should I use . I also have a HH Gyro. I do have a charger its a PANDA Radio control ac/dc auto charger with a 15min timer Can I use that to charge a 1200mah pack . I use it to charge my glider battery which is 9.6nimih. Could that be used or do I need a diffrent charger. Thank You

-pkh-

My Feedback: (2)

There are different main types of chargers: peak, trickle, & timed. If the Futaba is a trickle charger that puts out 50mA, you should be able to charge a 1200mAh batt within 24hrs (24hrs X 50mA = 1200mAh). If it's a timed charger designed to put out 50mA and charge only a 500mAh batt, it will shut off in 10hrs. To get it to charge a 1200mAh pack, you'll have to power cycle the charger 2 more times to reset the timer and get 24hrs of charge time out of it. The the Futaba charger I have for my RX/TX batts is a trickle charger (I'm pretty sure), so I'd guess your's is as well. If your's is a trickle charger, and it won't get your pack fully charged after 24hrs, then your pack is probably bad.

I wouldn't charge your batt pack at any higher rate than 1C, or 1.2A (i.e. 1hr of charge time).

alien

Hi Pkh Thanks for the advice I will try it for 24 hrs and if it dont fully charge it I will knon then the battery is no good . Question thought what do you mean by POWER CYCLE Please let me know Again Thank You .

-pkh-

My Feedback: (2)

If the charger is a timed charger, then it will stop charging after a certain period of time. Usually there is an indicator light on this type of charger to show when it is charging and when it has stopped. If it's set to stop charging after 10 hours, you can disconnect the battery and reconnect it to start the 10hr countdown again. I said "power cycle" the charger, meaning to disconnect the power to the charger and reconnect it to restart the timer, but I believe disconnecting the battery and reconnecting it is the better way to do it (I think most timed chargers reset that way).

If your charger is just a trickle charger, then it will not have a timer, and it'll charge as long as you keep it powered up and the battery connected to it. The Futaba RX/TX batt charger that came with my 9CHP appears to be a trickle charger, so I'd guess that's what yours is. The timed chargers usually put out enough current to charge a batt in an hour or less. The chargers that put out 50mA - 100mA (and charge batteries in 10hrs+) are usually just untimed trickle chargers. Most batts can be "overcharged" at this low current because they just get just slightly warm. The higher rate chargers need to have a shut off because overcharging at the higher current rates heats batteries up a lot, and could damage them or cause a fire.

alien

Like I said Thanks PKH I will try chargeing it for 24hr and if it still reads 4.4 then I know its the battery . As a matter of fact I am chargeing it right now. Again Thank You .

ChopperMike

If you're talking about the wall charger that comes with a Futaba (or anyone elses radio) they are not automatic chargers that shut off after a certain time. They are a 1/10 rate overnight charger, meaning they are designed to supply 1/10 the rated capacity of the battery. For example, a 500 mah battery will then be charged at 50 mah for 12-15 hours.

There is a problem, as planelazy stated, that the battery will not fully charge no matter how long you keep it on the charger. A 50ma charger on a 500ma battery will not supply 50ma to the battery for the entire duration of the charge. Towards the last half of the charge it decreases to probably half due to the higher internal resistance of the battery. The losses due to heat will mean that the battery will never reach full charge if the charger is not close to the 1/10 rate recommended. That's why they say to charge the battery for 12-15 hours rather than the 10 hours it should theoretically take. Unless you charge your battery at close to it's 1/10 rate, it will never fully charge.

I would use, as w.pasman said, at least a 1700 mah battery. I use a 3300 mah NiMH and still have to quick charge at the field ocassionally.

Hope this helps,

Mike

-pkh-

My Feedback: (2)

Well, if you've actually had that happen to you, I can't really argue with that. I guess if the trickle charger is severely under-rated for the batt your charging, that could be a problem, but charging a batt that's only 2-3X larger than it was intended for shouldn't be that bad.

Here's my experience...
My Futaba charger puts out 100mA and was meant to charge the 1000mAh NiCd RX batt that came with my 9CHP. I've had no problems fully charging a 2100mAh NiMH RX pack with it.

The current output of the trickle charger does drop off as the batt charges and it's voltage increases, but this means the heat loss does too. In fact, the average current the charger puts out shouldn't change much, since the larger pack will have it's voltage increase more slowly than the smaller pack.

Either way, if you can afford a good peak charger, that's definitely the way to go! I have an MRC SuperBrain 969, but don't have connectors/adaptors yet for my RX/TX batts, so I'm just using the Futaba trickle charger right now!

basmntdweller

My Feedback: (9)

Don't try the Panda charger. It is designed for fast charge nicads, generally more for toy RC cars and such. They have no monitoring of any kind. Rx packs are generally not suitable for high charge rates (more than 1C). If you leave your pack on the standard Futaba 50ma charger for 24 hours and you don't get over 4.6volts then you have a bad cell in the pack of there is something wrong with your charger (not likely). You pack should check at least 5.2v fresh off charge with a loaded meter.
Later,,,Matt

alien

Hi Matt Thanks I will check it out . I am not sure if it did reach 4.6 I am going to charge it again with the futaba charger and then check it . Again Thanks I will post again the results