Meeting of the minds

[Kaze]

Ladies and Gentlemen, I'm hoping to come to a conclusion really soon about this matter. Hopefully, with all your help, a solution will be met that'll progress my projects.

As some of you might remmeber, I started well over a year ago a 350Z project that recieved quite a bit of attention. Now, as it's coming to a conclusion I hit a snag and I've spent some time researching and I'm just kind stuck...

Basically I've customized the Gen 1 chasis tray a bit to help fit the planned interior. However, this leaves a limited space for the EP, Servo, and Power Supply. The EP problem is solved by opting for a smaller miniZ board, while the servo problem solved with a HS-55. Power is the problem here, being that the stock battery holders are unusable on this chasis I was planning on grabbing some small sized cells to replace the AAA holders. The proposed solution being two Micro-T Cells in parallel providing 4.8V and 300mAh.

Basically I want some suggestions on selecting the smallest possble power supply for my Z, while providing the necessary voltage and good run times. Pictures and dimensions are currently unavailable (soonest i can supply some would be sometime next week). For an idea here's a pic i sketched on quickly:


The Green is the extensions i'd done to the tray (basically making it the floor of the interior), the Red is the space taken up by the motor, and the blue is the freespace for the battery's/esc.

use lithium poly flat packs that you would see on a evo. you can mount them in the same fasion as the stock battery tray, but they are very tiny and take up way less room. i think it would work perfect for you!

[Kaze]

i was thinking bought it but two things, this car's gonne be hard to control if i do that (i'm keeping it RWD), also i've been ill advised about using liths on miniz boards (kills the board quicker)

what really? never heard that one before... always heard mini z boards where better. so i dont see why they would die quicker. but im no expert so dont quote me.

How ever i dont think the lithiums would make it hard to controll at all. they are leighter weight than stock. just move them forward or backward to set the weight where you want it. shouldnt have any problems what so ever.

[Kaze]

its a think with the board getting too much voltage, the sttering eventually begins jittering while driving, which you could imagine, sucks. It's damage to the steering FETs I think... someone's welcome to correct me.

The liths might have too much power too btw, imagine me hitting the body against something that fast lol...

I might go with those liths if i cant find anything, but we'll see..you have the dimentions for the liths?

i can measure mine in the morning. i dont feel like running out side in the middle of the night in 2 feet of snow and 10 degrees to get a tape measure out of the shed lol.

[Kaze]

lol oh yea... you're on the other coast 3hrs behind me... >.< suns about to come out here merry christmas lol... least you get a white christmas, it was actually raining here

Originally Posted by Kaze

lol oh yea... you're on the other coast 3hrs behind me... >.< suns about to come out here merry christmas lol... least you get a white christmas, it was actually raining here

haha yup! only 2 am here! and dumping snow!!! (as if i dont have enough already)

[reaper]

id say SPR's idea is going to be your best bet
and because you are using a mini-z pcb then you will have a hobby grade transmitter
the advantage of this is that you can set the full throttle position on the handset so it in-fact is only using say 1/2 or 1/3 therefore reducing the tendency of spinning out
did i explain that correctly ? if not let me know will try to give a better idea

[Kaze]

You explained it right, my concern goes right back to the actual physical damage to the board. You're right that the controller would let me limit it, but it doesn't regulate the 7.4V which potentially kills the board. If someone could verify, or give a solution around this issue then i'll gladly use the liths... but there's just too much voltage going to the board in this instance.

[SkysTheLimit]

I thought the same about the voltage going to the PCBs, even though I've seen a lot of it done.
Might not help but the Lithium Polymer batteries come in different sizes, so you could get smaller ones (maybe not as much maH for runtimes) but they would fit a little better.
Good luck finding the right batteries.

[xmodzracer]

well im not sure how well it would work but you could use one of the two flat pack polymers in the set

[XMDrifter]

a NiMH saddle pack would be logical if you don't want overpower this.
4 AAA rechargeables.
add heatshrink and a good soldering job and you'd have plenty of room

[fieldfairy2]

well, it's come along way kaze, great job.

Here is a micro t battery:
http://www.aero-nuts.com/product_inf...roducts_id=420

3.7 volts, 400mah, It is lipo 1s2p
dimensions are there. I believe this would solve the ruining the board and control issues.

[Kaze]

hmm is 3.7V enough to power the miniZ board? hmmm

XMDrifter, a saddle pack? EDIT: oh yea, i was looking at one the other night thats like 4.8 volt and they're like 2/3 AA or AAA... any suggestions on which cells/pack?

[XMDrifter]

get the one with the AAAs. AAs are too big to have 4 of them squeezed in there

[Kaze]

hmm gotta a link? brand suggestion? or just pick at random? Also, i might need balancing weights to add some weight frome one side of the car to the other...

[xmodzracer]

try this

http://www.atomicmods.com/Products/T...er__13596.aspx

[color0]

Use two LiPos in parallel. 3.7v is marginally enough to power the Mini-Z board. Because it's LiPo, the 1V loss isn't as noticeable as if you were powering the car off 3 NiMH batteries.

All-Battery has a nice selection of LiPos, and Tenergy is a decent brand. If you already have a Li-ion/LiPo charger, then I'd go for LiPo.

[Kaze]

Originally Posted by color0

Use two LiPos in parallel. 3.7v is marginally enough to power the Mini-Z board. Because it's LiPo, the 1V loss isn't as noticeable as if you were powering the car off 3 NiMH batteries.

All-Battery has a nice selection of LiPos, and Tenergy is a decent brand. If you already have a Li-ion/LiPo charger, then I'd go for LiPo.

hmm i do have the charger already. So it'll be a smooth or good ride with just 3.7 volts? hmm the mAh rating will be nice.. I like this idea... actually lol... hmm any other ideas?