Mr.Purple (FW)

[JammyONE]

Re: Mr.Purple (FW)

Well Pink's battery is a 12v NiMH 5000mAh, the Discharge Current is 35 amps so, no go since the 900's are over 50amps oops, so putting in a 5000mah 4S Lipo Battery for both robot's maybe the best option.

And changing the wiring to a more thick wire that can handle more amps. In Leeds after each round the link becomes hot. I fear it may catch on fire. And how I wire it all up is through nuts & bolts with crimp rings.

[Ellis]

Re: Mr.Purple (FW)

Well Pink's battery is a 12v NiMH 5000mAh, the Discharge Current is 35 amps so, no go since the 900's are over 50amps oops, so putting in a 5000mah 4S Lipo Battery for both robot's maybe the best option.

And changing the wiring to a more thick wire that can handle more amps. In Leeds after each round the link becomes hot. I fear it may catch on fire. And how I wire it all up is through nuts & bolts with crimp rings.

This is exactly the issue then! Get a LiPo that can handle 100a cont. or more (shouldn't be particularly expensive in 4s), beef up the wiring from cables to connectors to link, and you'll have a whole new robot on your hands.

[Eventorizon]

Re: Mr.Purple (FW)

I have a 6 cell 30C 4000mAh Lipo (22.2v & 120A continuous) if you are interested. It was used to drive Conkers weapon motors (2 speed 900's) last year but we have upgraded to two 5 cells for more power.

[PJ-27]

Re: Mr.Purple (FW)

I'd consider your voltage too, the Speed900s are rated up to 24v and your only running them on 12v.

[Eventorizon]

Re: Mr.Purple (FW)

One of the model sites says they will operate between 12v and 40v

We are pushing ours by running at 37v but the performance increase is massive!

[psycho_fling]

Re: Mr.Purple (FW)

yeh speed 900s (the real ones at least) are rated upto 40volts

[JammyONE]

Re: Mr.Purple (FW)

This is exactly the issue then! Get a LiPo that can handle 100a cont. or more (shouldn't be particularly expensive in 4s), beef up the wiring from cables to connectors to link, and you'll have a whole new robot on your hands.

Well I plan to put 6mm thick wire on since the wire I'm using now is from Robo Challenge. Links? what kind of links are we talking about?

[Eventorizon]

Re: Mr.Purple (FW)

If you mean removable links then its simply a pair of connectors with a wire going straight out and in on one of the terminals so that when you pull it out you break the connection.

We use EC5's cos they are nice and chunky, easy to wire up, and can deal with short bursts of 120A

Some people use Deans connectors which are again chunky, slightly harder to wire up but unlike with the EC5's you will never get your polarity wrong when wiring up.

But its mainly personal preference and what the connector on your battery is.

[Ellis]

Re: Mr.Purple (FW)

Yes, I mean removable link. We used a single Deans in Tormenta and we'll be putting two side by side to double the amp carrying capacity for Tormenta 2.

[JammyONE]

Re: Mr.Purple (FW)

I like to ask about the safest way to set up a Lipo battery.

I know about some of the issues of using Lipo, like how it will bring a zombie apocalypse (exaggerating worry) pretty much what I'm asking is to how keep the robot electronically safe and to keep serious and non-serious event organisers happy for example, is it recommended to put a 100 amp fuse on the positive wire, some thing like that.

I think I should put a hard case Lipo battery in Mr Pink since he's got a aluminium base. Since I don't know the heat resistant of 6082 grade.

I like someone to recommend me to a quality Lipo charger.

[PJ-27]

Re: Mr.Purple (FW)

You'll need a fuse rated below the Burst current of your lipo.
Continuous current is amp hours x C rating, so get a fuse just above that.

Ali is incredibly heat resistant (why it's refined by electrolysis I believe), so I wouldn't worry. There was talk of a 3mm metal plate underneath all li-pos but this isn't actually in the rules. Plus hard cases are often plastic, and that'll melt well before any metal we use.

The only other thing to consider is make sure all your solder joints are very strong and clean, and that everything has decent heat shrink covering. You don't want a short and you don't want wires un-soldering themselves. Also decent gauge wire.

[razerdave]

Re: Mr.Purple (FW)

Tips (and rules) for lipos:

Fuse: The fuse must be equal or less than the max discharge of the pack. My fuse in Satanix is the maximum continuous current of my speedos. If your speedo is drawing its max current then there is something wrong. Better to blow the fuse than the lipo or speedo.

Metal box: As long as your robots base is 2mm non flammable metal you won't need a box. Padding when securing it down is essential, and make sure it can't slide anywhere.

Connectors: Deans or EC5's. Rules say they should be able to handle the amps, and with most lipo's only those would do. Plus, you can't accidently reverse the connection. The connections must be heatshrinked.

EDIT: Damn you PJ!

[Eventorizon]

Re: Mr.Purple (FW)

Get a Turnigy Accucell 6 for charging, that will cover all your charging needs up to 6 cells and will do NiCad, NiMh, LA, as well.

You can add an extra safety feature by using a lithium cut off.

Best way to avoid accidents though is over spec the battery. Conker had a 4000mAh lipo for its drive. We used it in 3 fights and only drew about 1.5-2A each time so no danger of draining the cells to dangerous levels.

Edit: Darn you PJ & Dave! :-)

[JammyONE]

Re: Mr.Purple (FW)

Just to make sure I got this right, to put it in a simple term. Get a fuse that's in between, just higher continuous current but less than the max discharge AKA max burst.

Now for some reason I can't find any information on the lipo I have.
Some lipo's show the continuous and burst discharge but no! Not my lipo.

What I have is a Gens Ace 5000mah 4S 50C Lipo Battery the discharge says 50C and I have no clue what that mean Oh and it has a Dean connector on it, that makes me worried about it melting.
I'm paranoid!

On other news I have cut the base for Mr Purple and the sides but the blade is done.

Can't show you the picture since the the board attachment quota has been reached but I think it's nonsense.

[archie2000]

Re: Mr.Purple (FW)

the board attachment quota is quite stupid I hope it gets fixed.
as for your battery I am probably wrong so I would get someone else to confirm.
if it was 5,000 mah 1c it could take 5amps.
because its 50c it can give 250amps of power.
well more than the stall of speed 900s
before you do anything I would wait for someone to
someone check that aswell please
don't do anything yet Lewis :|