Battery question...

Hi all,

Essentially I am really annoyed with the default battery holder that comes with the vexplorer.

From what I understand, the 6 AA batteries that it holds should come up to about 9 volts, however, I see people in this forum saying they are using the 7.2V – does this decrease the power vs using the 6 AA batteries? I’m asking because I want to replace the battery pack with a rechargable battery but don’t know if I need to get a 7.2V or if I can get a higher one like 8.4v.

Also, the connection between the battery pack and the receiver is a “stard tamiya” correct? If so, I was thinking of investing in a 5000 mAh 8.4V battery.

Here is what I would like to get and use: http://cgi.ebay.com/Venom-8-4V-5000-mAh-NiMH-Battery-Traxxas-Plug-VNR15277T_W0QQcmdZViewItemQQ_trkparmsZ65Q3a15Q7c66Q3a2Q7c39Q3a1Q7c240Q3a1318Q7c301Q3a1Q7c293Q3a1Q7c294Q3a50QQ_trksidZp3286Q2ec0Q2em14QQhashZitem5631f4b354QQitemZ370205307732QQptZRadioQ5fControlQ5fPartsQ5fAccessoriesQQsalenotsupported

The standard NiCad pack is nominally 7.2 volts, but is really more like 8.2-8.4 volts fully charged. It works fine, and going to a nominal 8.4v pack will shorten motor life. I’d stick with the 7.2. Yes, the connector is a Tamiya.

Thanks so much for the quick reply! So would these work good then?

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=170341652668&viewitem=&sspagename=STRK%3AMEWAX%3AIT&salenotsupported

Also, the batteries I have in it now are 6 AA 2450 mAh and the robot can drive around on carpet but starts to die out quickly, do you think getting more mAh might help? How much time (with a conservative estimate) do you think 3800 mAh will give me time wise with full functionality?

This is where someone else will have to give you some advice. They are the right voltage and the connectors look like the proper ones, but since I haven’t tried them I would be reluctant to say one way or another. Since I run a VEX competition program, we only use genuine VEX parts. I can say that the VEX batteries run a competition robot (usually with 8-10 motors and really intense activity) for multiple matches – something like 10-20 minutes without noticeable degradation. If you are a hobbyist who doesn’t have to deal with the rules, a 3800 mAh battery should last longer, but I’m sorry I can’t tell you for sure. Good luck!