12X Charging

[jimmyjam358]

Ok, I have seen and read some threads on this issue and recieved an insert on the charging of the battery. So I have some knowledge on the issue yet I am still confused. Why would you charge a 9.6v pack at 12v? And why would you want that 9.6v pack to read over 11v as fully charged. So I guess with that in mind, I charged my pack for 12 full hours and it only read 9.8v, so do I keep charging it with the recommended charger or do I charge it with my charger? And if I charge it with my charger do I charge it at 12v or 9.6v?
Lots of confusion here, I am just not sure what JR wants from this battery pack, and I dont want to void my warranty on this $1500 radio. I have to give many thanks to Horizion hobby for this because I won this at IRCHA this year and would have never had this radio otherwise, so THANK YOU IRCHA AND HORIZON HOBBY!!!!!! In the end though I need some help with this, Thanks in advance for any information. :cheers

[joediamond]

And why would you want that 9.6v pack to read over 11v as fully charged

It's normal for a 9.6v nimh pack to read over 11 volts when fully charges. 9.6 volts is the nominal voltage for the pack, not the maximum.

[zeb29]

Having gone through the battery issue with my 12X including a trip back to Horizon, I'll offer a few suggestions;

Don't use the included charger.... I think the official recommendation is now to not charge for more than 10 hours, but I'm still leary of the 12.0 volt output. Most of the guys I ran into who'd had battery issues went with the smaller walwart which comes with either the 10X, X9303 or the DX-7 which is a standard voltage and 110 mah output. I tried that initially and it does work, but takes a long time....

I like this charger and it's the one I've been using since they came out:

http://www.horizonhobby.com/Products/Default.aspx?ProdID=JRPC223

I've used this charger on a NoBS 2700 mah pack, the JR 2000 mah pack and now have an Eneloop 2000 mah pack, it works great on all of 'em. Ten hour max charge time and the Eneloops are my favorite due to the extremely low self discharge rate and none of those will void the warranty as they're all NiMH.

There is one thing you need to do with high capacity NiMH (basically anything over 1650 mah) and that is to do a "forming" charge routine. Also, don't use field chargers on 'em as they don't like anything above a 1/10C charge rate. If you must, I've seen information to the effect that you can occasionally charge 'em for a bit a 1/2C but as long as they last, I see no reason to need field charging.

Here's a great FAQ on NiMH batteries:

http://www.hangtimes.com/rcbattery_faq.html

Hope that helps?????

Oh, missed a couple of questions; my batteries come off the charger in the mid 11 volt range and drop fairly quickly into the mid/high 10 volt range. I recharge when it starts getting down to around 9.6 volts, the low battery warning on the tx IIRC is about 9 volts and that's too low for an 8 cell pack.

So at 9.8 volts I wouldn't be flying yet. I suggest you run the forming charge routine shown on the NoBS FAQ and it's gonna take a couple of days to do that, and recharge with some other charger. Either your field charger set at 1/10C, or something similar and pay attention to the temperature of the pack. Mine got hot as h*ll on the included charger and if I'd known then what I know now, that would have tipped me off that something was wrong. The charged battery should be slightly warm but not hot.

[jimmyjam358]

Thanks for the information, I have so far run 2 10 hour cycles on the battery so far and yes it gets hot. Though I still only have 9.4v so I am starting to believe that I have something amiss with the battery, I believe the charger is functioning based on the heat the battery puts off. I have a charger for the DX7 that I will use overnight to verify as it is only 150mah but even a 10hr charge should get me 1500mah into the battery. So I will go from there. Thanks again for the information.

[jimmyjam358]

So, after some more charging, and different chargers, here is my findings:

I have a charger for a 7202 JR, polarity was the same it charges at 11.4v and 150mah it charged in a few hours to just over 10v, so I figure the battery was taking a charge. I switched back to the 12x charger for 5 hours of charging, battery was warm to hot, maybe 90 degrees and the voltage was down to 9.6 again. So is it a charger issue and should I contact horizon or should I just keep charging with the 7202 charger? I have a friend who also has the 12x and has never had this issue at all. I would like it to work the way it was intended but alas at this point I am not sure I want to send everything back to Horizon.

[jimmyjam358]

It's normal for a 9.6v nimh pack to read over 11 volts when fully charges. 9.6 volts is the nominal voltage for the pack, not the maximum.

Yes I know but why would you want to charge it at 12v maybe 11 or 10.5 but a full 12v seems overkill to me? My multiplex would not charge the battery to that I dont believe, but low voltage alarm is set at like 9.4 volts. :arggg:

[zeb29]

I would like it to work the way it was intended but alas at this point I am not sure I want to send everything back to Horizon.

Your choice on sending it back and it's a spendy radio so you may choose to do that.

I will say that Horizon continues to maintain that the included charger is okay and there is one guy at our field who has only used the included charger and says it's okay but I'm not sure how much he's used it either. It took mine about 4 months of gradually decreasing run time to get to where it wouldn't turn on one day.

I was merely pointing out my experince rolled in with what I've seen other guys go through with this issue. I have no intention of ever using the 12X's included charger again.

Did you read the NoBS FAQ? It only takes once overcharging the batteries and they're toast.

[jimmyjam358]

I did read it and it is very informative, I have since talked with Horizon, which I might add a very easy company to deal with, but based only on my findings, they have sent me a new transmitter battery and they still stand behind the charger. I have talked with 2 other 12x owners who have used the charger flawlessly when used as described. I will see with the new battery, I cycled this one 3 times as described in the link provided, to no avail, I couldnt get the battery over 10.2v and it would immediatly drop to 9.6v. I believe a bad cell from the gate. Horizon seemed to agree, and even overnighted the battery will have it tomorrow so I will update for those interested when I have charged the new battery as stated in the 12x bulletin.

Also the Disc cycle on the battery only took 1hr to get the battery down to 9.5v at .1 amp and only took 22min to recharge only giving the pack 200mah back in. That cycle was done 3 times with a 45min break between cycles.

[jimmyjam358]

Update:

So I got the new battery, decided I wanted to see some specs on the charge so I charged with my charging setup. After 2 hours votage is just under 11.4v and the battery is not even warm to the touch. Seems like it was a battery issue. Next charge will be with the 12x charger so look for an update in a week or so. Thanks for all input on this issue.