Batteries

[GoldDigger]

Hey are we allowed to use Lithium Ion or Non-Alkaline Batteries??

[InfiniCuber]

Hey are we allowed to use Lithium Ion or Non-Alkaline Batteries??

Yes, there is nothing in the rules that says anything against them!

[Bazinga+]

Hey are we allowed to use Lithium Ion or Non-Alkaline Batteries??

Yes, Buuuuuttt... Not quite. The voltage Limit for battery packs is 7.2 and, unfortunately, LiPo batteries consist of 3.7 volt cells, so a 2 cell LiPo battery is not allowed, and a 3.7 volt is impractical. LiFe are also impractical (arent really meant for electric cars), so I recommend just getting a high quality NiCa battery with large capacity (5000mAh).
Also the reason for limiting battery packs to 7.2 is because 7.2 volt rechargeable batteries peak at just under 9 volts, the intended limit, and 7.4 volt LiPos can reach voltages higher (~9.2), but it would have been really nice if the limit was 7.4 and not 7.2, and .2 volts doesn't seem too drastic to me.

[InfiniCuber]

Hey are we allowed to use Lithium Ion or Non-Alkaline Batteries??

Yes, Buuuuuttt... Not quite. The voltage Limit for battery packs is 7.2 and, unfortunately, LiPo batteries consist of 3.7 volt cells, so a 2 cell LiPo battery is not allowed, and a 3.7 volt is impractical. LiFe are also impractical (arent really meant for electric cars), so I recommend just getting a high quality NiCa battery with large capacity (5000mAh).
Also the reason for limiting battery packs to 7.2 is because 7.2 volt rechargeable batteries peak at just under 9 volts, the intended limit, and 7.4 volt LiPos can reach voltages higher (~9.2), but it would have been really nice if the limit was 7.4 and not 7.2, and .2 volts doesn't seem too drastic to me.

I completely forgot about that! Good point!

[rigor_boi]

Would a 7.2V NiMH battery pack with a 700mAh capacity be sufficient? I'm not sure if I will be able to draw enough current from that to run 4 brushless motors... Also I'm not too pleased about this fiasco with 7.2V instead of 7.4V because I had a LiPo battery to begin with and these rules are forcing me to purchase a new one for pretty much no reason.

[Bazinga+]

Would a 7.2V NiMH battery pack with a 700mAh capacity be sufficient? I'm not sure if I will be able to draw enough current from that to run 4 brushless motors... Also I'm not too pleased about this fiasco with 7.2V instead of 7.4V because I had a LiPo battery to begin with and these rules are forcing me to purchase a new one for pretty much no reason.

To be fair, LiPos are quite dangerous. Also, whyyyyy do you have 4 brushless motors... Whyyyyyy. Like 300 bucks out the window. The max acceleration is g since you cant get more than mg traction force, and one brushless motor can easily pull that. Also 700mAh will need to be recharged very often, so I recommend.a 5000mAh

[rigor_boi]

In my defense, the motors are from the same project that the LiPo battery was from (an underwater ROV from a few years ago). But you are probably right... using only one motor will reduce the concern for having enough current draw capacity from the battery and should be fine anyway.

[GoldDigger]

But a single 9V Lithium Ion battery should be fine right?

[InfiniCuber]

But a single 9V Lithium Ion battery should be fine right?

Well, not 9vV if it's commerically available and rechargeable. That's limited to 7.2.
If you are talking about like the Energizer lithium batteries that are 9V, sure.