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Old 02-02-2005, 12:13 AM   #1
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Default Batteries for Nitro vehicles

Attn: Ok, incase you are like legally retarded or something, I'd like to try and make you understand something. This is not a post about Buggies, this is not a post about Trucks, this is not a post about Sedans, this is not a post about Rally cars, this is not a post about any specific car. This is a post about AA battery packs used to power recievers and servos in Nitro cars.


That having been said, on to the question.


What are you using to power your reciever and servos in your nitro vehicle?

Right now I'm stuck with 4 Alkalines in a regular battery holder and am not quite sure what to go to instead.

Thanks
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Old 02-02-2005, 11:07 AM   #2
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Most people that run their cars with any frequency buy a Nimh receiver pack for their car. You have to find a configuration that will fit into the space on your particular car. Several companies sell them, such as Reedy, Trinity, Promatch, Orion, or in one case, I went to Fry's electronics and bought batteries and shrink wrap and made my own. Remember that alkalines are 1.5 volts and Nimh are 1.2 volts. That is why there are 5 cells in receiver packs. If you have a local hobby shop that sells RC cars, they should be able to help you with this.
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Old 02-02-2005, 11:39 AM   #3
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Thanks for the info!

Team Orion has some for 14.99, seems pretty good. The plug alone (from my lhs) would cost me 5.99.

Now I just have to figure out how to charge the blasted things (as I can't afford a 125 dollar charger).
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Old 02-02-2005, 12:37 PM   #4
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My LHS has chargers that go into the lighter port of your vehicle. They go for $15 Canadian so probably somewhere around $12.

And just to give you an indication as to how many configurations there are, out of four vehicles that have that style of pack, I use four different configurations. I have a flat, humpback, 4+1 hump, and a flat 4+1.
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Old 02-02-2005, 08:21 PM   #5
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This is from Team Trinity's website:

"The secret to charging Ni-MH cells is to keep them cool and not let them overheat when charging. Heat is the enemy of Ni-MH cells, so they need to be charged on high quality chargers that let you adjust the peak detection point (Negative Delta Peak) like the Novak Millennium. Negative Delta Peak is the amount of time the charger keeps charging after the cells peak. On most chargers this is set high for Ni-Cds and must be reduced. Ni-Cd cells like to be over-charged to reach full peak, but Ni-MH cells DO NOT. They heat up very quickly as they peak and putting them into this "over charged" state will cause them to vent."


That 12 dollar charger doesn't have any form of auto-shutoff, much less a Negative Delta Peak, so either I have to baby-sit the batteries, and keep unplugging them every half hour or so and check to see how they are comming along, which I don't have the patience to do nor the time, or get a real charger. Especially since they will need a different amount of time to charge each time.
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Old 02-02-2005, 09:19 PM   #6
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Then the option is to go out and buy that $125 charger. I had no problems with my batteries charging off of one of those chargers. You can get peak detection chargers that cheap. As a matter of fact, the one I was using was.
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Old 02-02-2005, 09:24 PM   #7
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Dude, if all your going to be charging is rx packs it would be much cheaper to get 2 packs, charge em both with the 12 dollar charger the night before and be done with it. Two packs will get you thru a race day. One will most likely. Those wall charges will tell you how long they need to charge. There is a forumla you use with the mah of the charger and the pack to get the time also. Nothing wrong with doing it that way either.
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Old 02-02-2005, 09:39 PM   #8
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Scott: What charger were you using that had peak detection and only cost 12 dollars?

Jbrow: Care to explain the formula then? Cuz I obviously don't know it...
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Old 02-02-2005, 09:45 PM   #9
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I'll try and find the link. If I can't I'll pm an engineer guy who knows it and get back to ya. Prolly tomorrow.
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Old 02-03-2005, 03:59 PM   #10
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1 amp charge takes an hour. Charging an 1100mAh pack at 1 amp will take just over an hour. 1 3300 will take almost 3 1/2 hours, from a dead start. That's the theory behind it at least.

I will try and find the charger. I'm pretty sure my LHS still has them.
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Old 02-03-2005, 04:36 PM   #11
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That is correct, IF the charger puts out 1000mah. My charger puts out 45mah.

http://www.powerstream.com/

They appear to be the only company in the world that makes a cheap charger with Negative Delta Peak adjusting.
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Old 02-03-2005, 04:59 PM   #12
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Posted by a smart fella in another forum answering my post.

Just divide the mah rating of your battery by the charge rate in mah, then multiply by 60. So, for a 3300 at 5amps, (3000/5000) * 60 = 36 minutes if the battery's fully discharged. There's always a little variance because the battery's rarely fully discharged, and they actually usually peak at a higher mah rating than stated (my 3300's are peaking 3600 or so). But, it gets you in the ballpark.
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Old 02-03-2005, 05:01 PM   #13
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Ok, but the problem is, does that change when you are charging more than one battery in series?
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Old 02-03-2005, 05:14 PM   #14
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You mean as in more than one battery in a 6 cell pack? Or two separate 6 cell packs at the same time? You'd have to have a charger that puts out alot of volts to do that. Most chargers run off 12 or 14 volts. Whatever you use for a power supply. If you are talking about a charger you plug in the wall I'd be surprised if it was over 12 volts.

Lets just say you can't charge a 14.4 volt battery (two separate six cell packs) with a charger running off 12 volts.
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Old 02-03-2005, 05:27 PM   #15
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No, neither. I mean the same thing as all these posts center around. Charging 4/5 cell packs for powering recievers and servos in nitro vehicles. Nothing to do with electric vehicles, nothing to do with 6 cell sub-c batteries at 3300mahs. This is for 700-2100mah AAs.

If one 2100mah battery charging at 1000mah takes 2.1 hours, then does it make sense that a 5 pack, wired in series, would take 10.5 hours? Or does it still only take 2.1 horus? Everyone keeps implying it only takes 2.1 hours no matter how many batteries there are, but that makes no sense whatsoever to me.
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