Ok, now what?
 

I'm still waiting for the Super Brain 989's to become available and my new LiPo packs should be arriving any day now. So can someone please tell me if there is anything else that I am going to need to run these on my setup. My setup being the dual 7XL's with two 5s LiPo packs

What I have now (or will soon have when available).......
2 Maxamps 5s LiPo's
2 balancers (one for each pack and charger?)
1 20amp power supply to run both chargers on
2 Super Brain 989's (soon)
2 7XL's (soon)
? ?????

Thanks
John

I would suggest some kind of LVC. (low voltage cutoff)

Man, its going to be sick. Hope you got Ultramaxxed gears. Thats the same setup Outkast187, Brian from BPP, ran on his Racebomb when he was big on the E-Maxx about 2 years ago. I remember he hit 54mph in first gear and then shredded second gear. This was before the ultramaxxed. He also didn't have LiPo's so he had stacks of batteries and it was a tank but hard to drive at higher speeds he said.

Here's a very small LVC that you can use:
http://www.dimensionengineering.com/LipoShield.htm It's one of the cheapest that I know of. You may want two of these, one for each battery. You would hook them in series together (one's RX cable to the other's RX cable input).

what controller you got comming for your 7XL motors

I think he is using 2 9920's

what kind of burst amp rate can your packs do?

I think you will need two LVC. One for each pack.

I believe that LVC's (or at least Dimensional engineering LVC's) are conntected at the esc. But you will still need two LVC's.

Is sufficient one lvc for two pack...

You can run one lvc if the packs are hooked together. Johnny is going to run two systems with two seperate lipos.

Thanks guys.
Metal Man, the only question I have about that LVC is about the part were they say "When you notice the aircraft becoming sluggish, it is time to bring it in. The cutoff can be reset by throttling down to zero, then throttling back up. This enables a “go around” to prevent emergency landings and long walks to retrieve your plane."

Throttleing down to zero is done quite a bit when driving vs. flying. Is this going to be an issue with the LVC getting constantly reset? Or am I not understanding it correctly?
Thanks.

yes cool is right...
:)

The part with the "sluggish" movement has to do with the LVC lowering the RPM of the motor (through the signal from the receiver), preventing the batteries from dropping their voltage below 3v/cell.

Having the LVC reset a lot could be a possible problem. virusss might be able to provide some feedback, but it also wouldn't be a bad idea to contact Dimension Engineering about it.

http://66.241.195.91/lithium/lithium.asp?path1=lithium
I kind of like this one a little better. It does about the same. I don't think it has the bypass. Mike said something about getting these. You may want to check with him.

What do you mean by "bypass"?

If you refering to me metal man. The lvc has a bypass mod in it. If you return the radio to zero and then to throttle again it will keep on with no limit. Unless i read it wrong. With cars you are going to zero position alot with braking and reversing. This don't sound like a good lvc for a car.

I think what it means by "resetting" is that if you go to neutral on the transmitter, (since the LVC device will reduce the motor's RPM as the cutoff), the LVC device will allow you to give the car/airplane some throttle without slowing the motor down again, until it hits 3V/cell again.

I am wrong. It is go around mode. Which does not sound exactly safe to me.

I wonder if the LVC that you linked Leroy does the same thing? I'll have to check with Mike, if he is going to carry these things, maybe he can shed some light on this.

I have a Li-Safer in my G3R. I will let you know if it works as soon as I know.

Thanks Daf.

How do you wire the Li-Safer if you run 2 packs in series, I wonder if I will need one of these at all I am using the MGM 16024 and it has lipo cutoff built in.

Easy! You just wire it to the input wires of your esc, just as you do with an UBEC. So it gets the full series voltage.

My guess is that this happens because when you "throttle down to zero" the battery's voltage will rise from the lower level it was at, so you can once again apply throttle before it kicks in at 3v/cell.

I sure would hate to risk a set of batteries to find out metal man. I think for the couple extra bucks I stick with the li saver.

Hey daf let me know how it works out.

I could use my ICE charger with its variable voltage output to imitate a 2s Lipo battery, with a controller and motor attached, hooked up to the LVC device and a receiver. The voltage would start out anywhere above 6v, and then I would take it below 6v to test how the LVC device causes the motor to operate. Besides, there is no evidence that a LiSaver will work as planned.

If I had $20 to spare, I would buy the Dimension Engineering LVC, but unfortunately I already have my next $150+ planned out (that'll take me a few months to get).

I emailed them:

Hello,
As long as you are using lithium battery packs it should work!
The only thing to keep in mind is that it won't work if you are tring to drive something in reverse.
Cheers,
Hisham
DE

----- Original Message -----
Will the Lipo shield work with RC-monster trucks? Thank you!

The reverse part doesn't sound too good, but otherwise it should be fine. Personally, using reverse isn't a necessity at all.

Now, does the Li-Saver have this same problem?

I personally like reverse (when you drive as bad as I do, you need it) so I would be curious to see if the Li-Saver is this way as well.

got any updates johnnymaxxima? Did your batts come? Lets get some pictures!

two questions:

Any updates? Pictures?

Where are you buying your power supply for the charger? I am going to be using the same charger, but am unsure as to what power source (DC).

Hey Superemaxx,
I should be getting the batts any day now. I contacted them (Maxamps) last friday when I still hadn't received them. They received my money but missplaced my order. So they should be here soon.
I bought this power supply from Hoby People (had chrismas gift certificates) and it was recomended by a few people here for me to run 2 chargers at the same time on. May be a little over-kill for one charger though. http://www.hobbypeople.net/gallery/158301.asp

I also contacted MRC about when the 989 would be available and this was their quote... "Right now we're looking for late Spring / early Summer for the Super Brain 989."
So I may have to look elsewhere for a charger cause I don't feel like waiting that long.

Late Spring/ Early Summer, thats sounds good enough for me though. I probably won't make the Lipo switch until the summer time when I start really working again after school ends.