newbie question on batteries
#1
Thread Starter
Tech Apprentice
Joined: Jun 2009
Posts: 72
Hey guys Im new to the 1/8 buggys class and have a few questions on batteries. I have 2 hump pack nimh that I run In my buggy. I have a hyperion charger that I charge these at 1.6 amps. Is it bad to recharge a battery thats not discharged all the way? What is the advised setting to discharge these batteries? Also is it recommeded to discharge my 12v that I use for my starter box? thanks dudes
#3
Joined: Jul 2008
Posts: 11,530
From: Houston, TX
If thats a 2/3a rcvr pac (the cells are about 2/3 the length of an AA cell) thats too high of a charge rate - the pac is getting pretty hot I'll bet. You won't get much life out of it charging it that way. Even if its AA size cells thats a high charge rate.
You're 'teaching' the pac to dump like racers did when they charged their race pacs at high rates and thats not what you want from a rcvr pack. You'll get better life and longer performance if you charge at 0.5amp when you have the time and can charge at 1amp when you're in a hurry. The slower charge rate helps out with not being discharged fully since it gives the cells a better charge at the low rate.
You're 'teaching' the pac to dump like racers did when they charged their race pacs at high rates and thats not what you want from a rcvr pack. You'll get better life and longer performance if you charge at 0.5amp when you have the time and can charge at 1amp when you're in a hurry. The slower charge rate helps out with not being discharged fully since it gives the cells a better charge at the low rate.
#5
Tech Regular
iTrader: (7)
Joined: Mar 2010
Posts: 308
From: wichita ks
i would have to agree with duster on that one. that receiver pack should last u most of day long as ur not running a high voltage servo for steering. i would charge it at .5 amps if im at home and have the time to charge it like that but if u are racing and need the pack in a hurry then i would do 1 amp or up to 1.6. its really up to how u wanna charge ur packs
#6
Joined: Jul 2008
Posts: 11,530
From: Houston, TX
If you're using a gel cell or SLA batt for starter box, I don't discharge them before recharging. If you're using a pr of NiMh you can discharge them to 0.9v/cell (5.4v for a 6 cell pac) and then recharge. I'm not sure discharging stick pacs does much good though since you really can't control what the individual cell in the pac are doing voltage wise. Use a low discharge rate if you do, the lower rate will take longer, but will give you cells at closer to the same voltage than a higher rate discharge will.
The objective behind discharging NiMh is to get all cells at same voltage level. Since you can't do that with stick pac, you could give it a real slow charge every so often, like every 10 charges or so at C/10 for 14-16hrs (C is capacity (mah))- that may be the best bet you have for putting cells at same voltage. You can do this easily with side by side pacs on a discharge tray, but its hard to justify the effort for pacs just used for a starter box.
The objective behind discharging NiMh is to get all cells at same voltage level. Since you can't do that with stick pac, you could give it a real slow charge every so often, like every 10 charges or so at C/10 for 14-16hrs (C is capacity (mah))- that may be the best bet you have for putting cells at same voltage. You can do this easily with side by side pacs on a discharge tray, but its hard to justify the effort for pacs just used for a starter box.




