View Full Version : Charger Question

06-17-2004, 09:20 PM
In an effort to save a little amount of money, I was hoping to use the charger my younger brother uses for his RC car. It is a Duratrax Piranha AC/DC charger.

First, are the cells in the mini packs sub-C cells? If not, I am assuming that it would be unsafe to use a charger that specifically states "handles 6-7 cell, sub-C NiCd packs."

Second, the charger is a peak chager and states it is for use with '1200-2000mAh' packs. Would it be possible to use the charger like a wall charger and time the charge, removing the battery before it is cooked?


06-17-2004, 09:49 PM
Mini batteries are not sub-C cells.

Even for mini battery packs, the charger you listed will be fine, as long as your charge rate is low. 1A is good for mini packs (I'm assuming you have a 8.4v, 600mAh pack when you say you have a mini pack). This is the most important thing......check to see what the charge rate is.

Under my above assumption about what pack you have, it would be safest to time it like you mentioned. It sounds like that particular charger doesn't have circuitry sensitive enough to detect the voltage change for a mini pack, which tells the charger that the pack is fully charged.

06-17-2004, 10:02 PM
heh, well the charger reads 'Fast Charge: 4.5A Max Trickle 50-300mA' im guessing a new charger is in order.

On a side note, it does have a place for a 1A fuse, is that for power going out to the battery?

Also, the battery is indeed an 8.4V, 600mAh pack.

06-17-2004, 10:22 PM
Yeah, definitely do not charge that pack at 4.5A unless you feel like burning it up.

What are you using a mini pack in? If you intend to upgrade in the future, be prepared to buy larger-capacity packs as the mini won't serve you well.

06-17-2004, 10:24 PM
An m4, but i dont plan to do any spring upgrades in the near future. Later plans involve a modified APS2 w/ the m4 to use under the gun so a tightbore & reliablility upgrades may be all the M4 gets beyond cosmetics.

06-18-2004, 10:34 AM
well I just lost a bet with my brother. He just showed me that the current charger we use can be run at a trickle only. Since this is only 300mA i'm guessing it's safe to use. Now I'm off to go find that charge calculator.

06-18-2004, 10:45 AM
New problem. The charge calculator gave me a range from 14hrs at a 50mA charge, to 2hrs at a 300mA charge. This is the range the charger has written on it. How am I supposed to know when my battery is done charging?

06-18-2004, 12:53 PM
Are you saying that the charger will trickle anywhere from 50mA to 300mA?

06-18-2004, 06:58 PM
yes, thats what the charger has written on it

06-18-2004, 07:36 PM
Ugh, that is tough since that rate is a large range.

06-18-2004, 07:57 PM
so, 2 hrs? seeing as how that is the safest way to do it ensuring that the battery doesnt get overcharged? Would a partial charge the first time hurt the gun?

Also, could you possibly connect a meter to the charger before you connect the battery to see the rate? I cant imagine it would flux too much.

06-18-2004, 08:07 PM
1. I've been drinking and getting a nice buzz after a long week at work.

2. 2 hours is a good baseline to start with......it won't hurt your gun if the battery is dying/not working well.

3. Yeah, a Fluke meter would be able to determine the amperage rate, fi you have one.

06-18-2004, 10:21 PM
finished 2hr trickle. I just plugged it into the gun, and the motor didnt even turn over. nothing happened. It wasn't on safe, and the fuse is still good so I'm guessing it just needs more time to charge.

06-18-2004, 11:00 PM
well, I just busted out the multimeter, switched it to measure in 50mA increments, and plugged it in. Got ~30mA reading. dang this thing is trickling, I wonder if my rigged adapter has anything to do with it. I had the guys at hobby town make it for me out of some connectors they had there for about $5, but I wonder if the connections are slowing it down at all.

06-19-2004, 11:15 AM
Update: Battery still doesnt work in my brand new M4. I took the multimeter to the battery to measure volts...grand total of ~2volts after a 12hr trickle charge...I think it may be time to invest in a decent charger that won't blow up my battery.

06-19-2004, 11:35 AM
Take a look at the MRC Super Brain.....nice little charger: http://www2.towerhobbies.com/cgi-bin/wti0001p?&I=LXAVN1&P=ML

Durtrax Intellipeak Series is another to look at......you can likely find them a bit cheaper on Ebay if you care to go that route.

06-19-2004, 06:44 PM
hmm, I may look into it. Alas, the gun still does not operate with my battery even after further trickling today. You think this may be a gun issue?

06-19-2004, 08:29 PM
Until you have a proven good battery, I wouldn't bother worrying about the gun. If you are coming to tomorrow's skirmish, look one of us up.

06-19-2004, 09:10 PM
I wish i could, but work says otherwise...:-(

06-21-2004, 07:51 PM
I've got another charger that has an output of 12vDC 200mA. Is this fine for my battery?

06-21-2004, 08:33 PM
Yeah, that'll work. If your battery is all the way discharged, try charging it for about 2-3 hours. There is an online charge time calculator in the Airsoft FAQ in the battery section that'll help with that.

06-21-2004, 08:42 PM
Yeah, already found the calculator. Thanks for all the help.