7.2 V battery packs in series

Lynxmotion Rovers, Sumo, and Tracked
1

How are you guys making out by using the 7.2volt battery packs in series with your rovers? I just ordered my rover, and had jim (Lynxmotion tech support) upgrade the standard gmh01motors with gmh12 motors.

What i ordered: A4WD1 Combo Kit with the upgraded motors

I’m also considering using lithium ion batteries instead of ni-mh battery packs because it should decrease weight for comparable amperage capacity… but it does dramatically increase expense.

Also, inside the rover chasis… what sizes have you guys found you can comfortably fit battery packs? The pictures in the assembly instructions… the one has two battery packs hooked in series to power the rover… are those 7.2 battery packs? What are the length x width x depth of those batteries? They looked like they fit in nicely and used up pretty much all available room.

Or perhaps they are the 6V packs. When I count the individual cells, I’m coming up with 5 cells per side in figure 12.

The picture I’m referring to: figure 12 from this link

lynxmotion.com/images/html/build122.htm

So I take it these are the battery packs displayed in figure 12?
lynxmotion.com/Product.aspx? … egoryID=48

The 7.2 pack (6 sub-c cell packs) would also fit?
Pack measures 5.25" x 1.75" x 0.875".

I found the following:
Voltage: 6V Capacity: 5 Ah
Max. Discharging rate: 5 Amp (or 5000 mAh)
Dimension: 5.0 (L) x 2.0 (W) x 1.0 (D) inches
Weight: 1.0 LB
Prewired (5 x C) with 4� cable and female connector and thermal protection. Additional 4� cable with male connector in one end for connection to the battery pack and the device to be powered.

I’m wondering if these would fit in the rover instead of the

6.0 Volt Ni-MH 2800mAh Battery Packs that lynxmotion provides. Those packs are listed as measuring 1.875" x 4.375" x 0.9375"
It looks like I’m increasing the pack width just a hair on each side of the controller in the picture.

Can someone with the setup in figure 12 measure the distance from the width edges of the battery packs to the controller in the center and tell me if they think I have roughly an extra .5 inch total to play with?

I take it that the standard radio controller i(the reciever side) included with the new kits are 12V as well?

2

The images in the assembly guides are of the V1 rover. We are now shipping the V2 rover. It’s chassis is 1" longer, 1" wider and 1/2" taller. You should have no trouble fitting those batteries inside the rover.

The radio receiver, as it is intended to control servos, is 6vdc, not 12vdc. You are going to need 6vdc for the pan and tilt anyway.

3

Yes I’m aware the pan/tilt will need 6v. Didn’t know about the reciever though. Ok, thanx, will arrange for that.

The 7.2 batteries (in series for 14.4 Vdc total), they a bit harder on the motors but provide a bit more “oomph” (speed) correct?

4

Yes it’s no problem to run 12vdc motors at 14.4 or 14.8vdc for a short time. You will get a 20% increase in speed. That’s 304 rpm with a final speed of 76" per second or 4.2 miles per hour.

5

For reference this is a definition of walking speed… Gotta love the internet!

Daily Steps: If you are just tracking your daily steps with a pedometer as you go about your job or putter around the house, you can use 2 miles per hour or 2.5 miles per hour. That is 3.2 kilometers per hour to 4 kilometers per hour.

Easy Health Walk: If you take an easy walk around the neighborhood or park, able to keep up a full conversation, use 3 miles per hour or 5 kilometers per hour as a rule of thumb.

Moderate to Brisk Walk: If you are walking at a determined to swift pace and breathing noticeably, use 4 miles per hour or 6.5 kilometers per hour.

Fast Walking: Fast walkers usually know their speed or have measured it. Racewalkers can walk 5-6 miles per hour or even faster. That is 8-10 kilometers per hour.