7.2V battery pack for rocket racers

[lbrin]

Just got a Rocket Racer and want to upgrade to a 7.2V battery pack for longer run-times and improved performance. Can someone tell me the difference between 2/3AA packs and AAA packs? What cell-types fit? And how does MAH affect performance?

Thanks!

[irc]

Any 7.2 pack that is made to fit the ABC SP, Aktiv RR or WWS Pro car will fit. The mAH is the amount of power the battery can store. I run a battery in my Rocket Racer that is made for the Aktiv car. It is 350 mAH. I also have packs that are 600mAH that will have more run time. I run the 350 because it takes less time to charge and seams to have more punch. You can use double sided tape to install a 7.2 in your Rocket Racer. This is the best hop up for the car so you are on the right track!

[lbrin]

Thanks irc. So are there advantages/disadvantages to using packs made from AAA vs. larger cells?

Thanks.

[irc]

As long as the pack fits the major diffrence between cells will be the mAH. I have made packs using AAA that fit in my Tamtec with 700mAH. IM not sure if this pack would fit in the DRR? if so it would have killer run time.

[Siress]

The owner of my LHS has been running his RR since they came out. He saw the potential that they had and has made hella adjustments to it. He tried some 7.2volt 1100mah batteries made for a micro RS4 (4 vertical-bottom, 2 horizontal-top, comes with correct plug already) and when you barely touch the trigger it spins out. He has a RS4 motor and foam tires among other things and still it would spin out. Something that I am going to try is to get the 15tooth pinion gear on the motor and try 7.2 and 6.0 volts in it.

Unless you have been driving your RR for a LONG time and are VERY good at it, I dont suggest that you go for a higher voltage yet. Stay at 4.8 volts (4 cells) and get the 1100mah batteries, that way as your driving skill progress you can add a cell and maybe add both other cells back. I will put some info about it on my site (link's in my sig) after I tinker with it.

[irc]

Wow thats a big battery for the DRR! IV thought about trying my Micro RS4 7.2 pack but the smaller batteries seam to work good.If your having rear tracktion problems try to let the diff slip for a few inches and use some traction compound on the rear tires. the larger pinion gear would help also. IV had a few of these cars for some time know but it sounds like LHS has really modified his.

[Siress]

he doesn't run 6cells anymore, only 4. In fact, mine is now much faster than his. I think I have the fastest but I can't tell yet, I dont have my RS4 batteries yet (on order) but I am as fast as one other guys new RR that he has modified.

[lbrin]

Specifally, which RS4 packs fit? What kind of cells? The ones I've seen seem to be too high too slide under into the battery space in the DRR - that's why I'm considering the AAA packs.

[Siress]

I think what you need is to get some of those AAA Rayovak batteries from walmart that are 700mah NIMH. Solder 6 of these together and put them in. thats what you need. Its 7.2v 700mah.

MAH = length of run time
high mah= long run time + long chargeing time
low mah = short run time + short chargeing time

[Siress]

Ok, I am not for sure on that yet. My packs didn't get order when I placed the order TWO WEEKS AGO!!! So I RE-orderd them today. I am pretty sure that they will fit but I dont know for a fact. Based on the measurements given to me by Tower Hobbies they do. that battery thing really pissed me off today. but the fact that the owner thinks that I am a theif or something is what cause me to go over the edge. (she lets me help put stuff on the wall behind the counter but thats the only time she doesn't mind now because she says that she "gets nervous" but that its not because of me she says, I am just venting)

[Siress]

this has been a while and I have been working on somthing for all DRR owners as a big suprise for most and to shut other mouths for them with their foot. Anyway, the Trinity Micro Zip-pack for the mRS4 with 7.2volts works fine. It is heavy though so the Rayovak batteries are better for top speed.

[dtmracer]

the 2/3 aa 7.2 battery pact has mah between 270 - 600 range i believe. you can get 700nimh aaa batteries cheap and actually make a 7.2 battery pack out of em with the same dimensions as the 2/3 aa pack but with a lower height!! so the aaa are in my opinion the best batteries for these cars. as for weight, i weighed my 270 nicd 2/3 aa pack vs 700 nimh aaa pack and the aaa pack was lighter but that may be because nimh battery packs are lighter.

[kev71H]

I have a 2 cell 7.2 volt battery. 1500 mah!

works great!!!!!!!!!

Have 2 of them...but charge time takes a while..but I have about 2 FULL HRS of run time..with a MODIFIED motor (orion MOD elite)

[fatdoggy]

What sort of batteries are they and where did you get them?

cheers.

[Tch0rT]

I ordered basically the same pack in this auction from the seller :

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=2565&item=3105339564

I asked him how big the pack is and he said that it was about 50mm x 50mm x 20mm which is about the exact size of the space for the battery compartment on the DRR (I measured with a ruler roughly). If it doesn't fit it'll be pretty close and probably not to hard to mod the DRR to accommodate. I can't wait to get it.

Right now I'm trying to finish up a model I bought to use for a body. It's not turning out as good as I had hoped (it's my first time doing a model so it's pretty new to me). At the very least it'll probably look better than my NSX stock body. I also broke a body post so I ordered the aluminum posts from horizonhobby.com. Now I really need some foam tires...

Ryan

[kev71H]

sorry, but my pack is nothing like the pack(s) I saw in your ebay link.

Here are pics of my batteries.

http://tinyrc.com/forums/showthread.php?s=&postid=53135#post53135

My packs are LITHIUM ION packs. And I charge them with a cell phone charger. It automaticaly peaks them. I orginaly bought them for my electric airplane park fliers..but they work GREAT in my DRR.

Sorry, but those packs are very very different.