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Old 03-08-2008, 12:12 PM   #1
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ok guys we are ready for our first battery charger. and need some input.
we have 3 rc10t4 trucks and hope to have 3 batterys for each truck.
i know we cant discharge and charge at the same time. so can some show me how to build a home made discharger? now for a charger, need your imput into what charger to get. one that will charge 2 maybe 3 batterys at the same time? ac/dc type.

thanks
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Old 03-08-2008, 12:57 PM   #2
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Buy three lipos and you will never have to discharge, problem solved and with lipo you only need a charge feature up to around 6-7 amps which should accomadate a large battery's needs. Lipo chargers arent really expensive.
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Old 03-08-2008, 01:43 PM   #3
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Purchase 3 lipos. Then you can wire them up so that you can plug them up in series for charging so you can charge them at the same time.
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Old 03-08-2008, 01:53 PM   #4
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where we are going to race is nimh only, also have 3 nihm now
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Old 03-09-2008, 04:20 AM   #5
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The way I hear you, you want to race 3 trucks at the same time and you're bound to NiMH. Right?

Assuming, you want to race three trucks simultanous...

If you want to get get max performance out of your packs, then they need to peak max. 15 minutes before the race - and the closer the better. Thus you're looking into 3 chargers.

I'll strongly recommend you get charger(s) with temperature cut off. Newer batts like Intellect 4200, are tough to detect the peak voltage on - even with quality chargers like LRP/Nosram. I have two chargers which cant auto cut off on the right side of 60 deg. celsius / 140 F. This will most likely shorten cell life, and it increase the risk of cell venting or explosion.

EDIT: Apparently it's easier to detect the peak voltage on my new Intellect batts after a couple of runs - it's working better now. It's still close to the edge, however, so I'll still recommend a temp based cut off.

The Duratrax Ice seems to be the charger with most value for money, and if you also get the temp probe, it can do temp cut off. http://www3.towerhobbies.com/cgi-bin...?&I=LXHDJ1&P=7 It requires a 12 volt supply, though. On the other hand, one good power supply, can handle 3 chargers

For discharger, it's somewhat easier - you dont have to discharge NiMh between heats/rounds on the same race day. So you can simply discharge all the batts after the race. Thus you can get away with one discharger. You could get a discharger like this: http://www3.towerhobbies.com/cgi-bin...?&I=LXKTR6&P=7

Cut off voltage should be adjustable. It also exist in a 10 amp and a 30 amp version. Then combine with a equalizer, and you are doing well.

As far as I can hear, you're somewhat on a budget - no, my recommendations aint cheap. But I believe it's the cheapest stuff, which still is good enough to take care of all your batteries, thus prolonging your battery investment.

Good luck, and feel free to ask again
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Old 03-09-2008, 07:56 AM   #6
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How about a 977 MRC.
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Old 03-09-2008, 08:40 AM   #7
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Quote:
Originally Posted by peterel View Post
where we are going to race is nimh only, also have 3 nihm now
They won't allow lipos? Even ROAR now allows them. Sad to see someone spend so much on virtually obsolete high maintenance technology just to get started. Need to politely encourage your track to pull their head out of the sand. It ain't like some newcomers are going to just show up and start dominating anyway. Offer to run "hard case" lipos only, use balance chargers, and use a charging sack if you have too if they think it's a safety issue. Even some of the big races are switching the rules at the last second, because their CUSTOMERS are demanding it. Remind them who's paying the bills!

Good luck, and welcome to the insanity.
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Old 03-09-2008, 09:09 AM   #8
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i agree with Dave, LIPO is taking over in the near future and nimh will be rare to find. the prices of lipo are dropping and the efficiency is excellent. you can easily run 2 heats and what we do at our local track, we do a 10 minute main. good luck doing 10 minute on a 3000 or 3600 nimh. you are going to have to spend a little more now for the lipo set ups but i would hate to see you spend a bunch of money on things you are going to upgrade in the near future. good luck to you.

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Old 03-09-2008, 09:27 AM   #9
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Gee dawg, we're on the same side here, but I disagree a little, isn't lipo cheaper to get started, or at least no more? Granted, a little more per batt, but fewer batteries, possibly cheaper chargers, no discharging capabilities or separate dischargers needed? He would need, what, at least 6 more nimh to go with his 3? He could get buy with 3 lipos, still use his nimh as back ups. Assuming everyones on the same team, a couple extra lipos and he would really be set, rotate them around. Even with lipos keeping 3 guys going is a challenge in itself, a full time job with nihm!

Good luck with your team peterel, and Cheers to all!
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Old 03-09-2008, 05:18 PM   #10
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For a charger, the MRC989 does a really great job with NIMH packs, lipos too, and comes with its power supply as well. For the money, it was an excellent charger.
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Old 03-09-2008, 07:25 PM   #11
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yes that is true dave, but don't forget that lipo batteries are more then matched cells. you can get 6 matched cells for approx $65. a good lipo is going to run you minimum $100. so i don't know his financial status or his comfort level with lipo. i personally would advise him to go lipo hard case and forget nimh. if you are safe with charging and not dropping below voltage, then they are fairly safe. always balance. just my 2 cents.
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Old 03-09-2008, 07:36 PM   #12
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I remember having discussions of safety about lipo and NIMH. the fire thing can be an issue with misuse, but the grenade thing that nimhs can do is also and issue with misuse. I guess it depends on a pick your poison mentality.
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Old 03-09-2008, 07:49 PM   #13
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true cain, anything with a positive and negative charge in the wrong hands can be dangerous. precaution must always be taken with batteries and should always be monitored and stored correctly.
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Old 03-09-2008, 07:57 PM   #14
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Good point Dawg, with 3 trucks running around a reminder about not running them down all the way is important. Peterel, ya either need an appropriate esc or an added on shut off if you go lipo, they will die if you run them down. Don't even leave them plugged in.

And I agree even more with Cain. Our solution to a possible fire hazard is to have explosions? With things that contain acid if I'm not mistaken?
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Old 03-09-2008, 09:02 PM   #15
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A LipoSack really eases my mind to any charging harm in my pit area. I've seen the videos where an abused/overcharged Lipo pack gets launched off a table but I can't imagine a fiberglass sack with a Lipo pack in it is going to hurt anyone too seriously.
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