Question for you guys running brushless and Lipos....
 

Hey guys, Alex from Boom Boom Batteries here. I'm thinking about stocking a new cell that is somewhat like a lipo. It has a 76A max discharge. My question is: If I have two lipos running on my set up (i.e. an E-maxx) that are each 7.4V with a 76A Max Discharge, when I go to run them, will my max discharge be 152A or 76A? I'm worried that 76A won't be enough for those of you guys running brushless... Thanks for your help!
Alex

it would be 76 amps. it should be plenty for most. they would only be 152 if in parallel. what kind of cells? price? mah?

They are going to be 3800mah 7.4V. They are completely different than Lipo in that they don't explode :) They have a higher voltage and more punch. Look for them in stock on RC-Monster soon... If you're interested in getting one earlier, PM me, and I can probabely get you one of my samples...
Alex

Could we have a pic please? thanks. Whats the size of the cells?

sylvester do you already have some lipos ordered? or not.
are you going to stick with your 3300s in 7 cell?:013:

i might order some of these batteries alex is testing!!!

They sound good will they require a different charger? What kind of charger will they use?

They use the same charger as standard lipos. They look like a Lipo in their build. Same size as a normal Nimh pack. Light like a Lipo though :) The only thing I need right now to release them is a decent Low Voltage Detector, anyone have one they like?

What will the price be? im looking into these asap:):)

you're talking about the li-mn aren't you:027:

Could we get some more specs?

As far as 76amps go, that number won't mean anything in a RC car. That could be the maximum continuous amp draw, or the maximum burst rate for 10seconds (you get the idea). These cars can easily pull very large amp spikes, but the batteries don't have to be specified to handle such large amp spikes. For example, my Eagle Tree MicroPower Data Recorder recorded a 97amp spike in my Rustler with a 4s 5400mah 8C/15C (43amps continuous/81amps burst) Lipo on a Feigao 540 12s motor. The cell voltage dropped to about 3.2v/cell, but the pack also was not warm (if it was, the voltage would have been higher).
The point I am getting at is that these amp draw numbers aren't all that important for car guys, but more for airplane guys.

As far as your question goes, if you have two packs in parallel, the possible amp draw rate effectively doubles, as long as the wiring/connectors can handle that.

What's the price going to be? Right now I have some cylinder-shaped LiFePO4 batteries that are better than NiMh in all areas except price and shape, but safer and more robust than Lipo (and can also charge at 2C). These are 3.2v 1200mah 16C cont. cells, and are $8.50/cell.

What are you looking for in a LVC? I could point you to the schematic of one that you could make (DIY) that could work for any voltage. What's the LVC for these cells?

I'll try to get to all your questions. They have a 20C Continuous rating (76A). They will be approximately $100.00 each. Yes, they are Li-mn.
Alex

will you be making any higher voltage packs

It really depends on how these sell... I'm sure in the future we'll be stockings something.... Metalman - let me know on the LVD!
Alex

I've been reading about them in the radio control car action forums for a while nowand yes i'm interested, just need more money

Does any one have a pic? I want to see what they look like.
as for LVD what about this. http://66.241.195.91/lithium/lithium.asp?path1=lithium

If i'm correct, these are the packs http://www.pfmdistribution.com/

if thats them, i would assume you can get them in a 3s configuration right?

Yep, those are the packs... They should be in this week - placing the order tonight - looks like I'm going with the LVD that Coolhand showed me or the HRPOLY-X - I'm going to run tests and decide which I like... I'm going to be selling them in a few different kits etc (with charger, with LVD, Seperate, etc. - now that I think about it, an E-maxx pack would be a good idea!). As for 3s, I believe they are on the way, but not in yet... Seems to me that with the weight you lose, these packs are going to increase speed by a good amount.
Alex

Keep us updated on the cells

also what kind of connecter are they going to come with.

They're going to be Dean's.

good i saw the pic on appogee and it had tamiya connectors which scared me

Yep, Dean's. Buying through Mike and I does have its advantages! The cells are also going to come with the LVD as an option, something which you need...

Will you be able to make custom orders? Like a 19.2 V pack? thanks.

I can make a 19.6V Nimh Pack!... However, the Li-Mn packs come pre-assembled, and the cells aren't available loose... In an E-maxx they should be pretty sweet - think about how much weight you're loosing!

According to the rc car action forums, they have no plans at this time to do a 3s or a high capacity pack. Unless you have got a deal for so many, because they don't think they will sell. Here is a link to the thread if anybody wants to read uphttp://forums.radiocontrolzone.com/s...d.php?t=213093

no body wants them. Gee where have they been. I like to have more mah though. Are you going to start carrying other lipos to alex.

You have to keep in mind that the 3800mah is all relative. It will probabely run longer than your standard 3800 pack because it is lighter, therefore the batteries are pulling less weight... I probabely won't be stocking any other lipos in the near future, as I don't like the Li-Po technology for cars except for Li-Mn packs. More info on that soon. However, if you need anything from Apogee, let me know and I can special order it very easily. We actually have a few really cool products in the works that will be pretty awesome which is what I'm spending most of my time on these days :).
Alex

So for each pack you will sell, you wont be selling over 7.4V? That stinks for the guys running higher voltages on their trucks:(

Unfortunately, there's nothing I can do about it. Apogee doesn't sell their cells individually - you could always wire the packs in paralell though... According to Apogees owners it works fine...How does 29.6V sound? (28 cell equivelent, weighs less than 16 cells) :)

29.6V? Sounds like somthing coolhandcountry would like:P

Hey that sounds about right. That would be in series alex not parellal. I was looking at about 30 cells but 28 will work just fine. especially for the weight. If i strap about 3 together on each side for a 6s and 2p that would work right. 7600 mah will the light weight to.

Hey those li-mn packs sound great. I am putting a 8XL and a 9920 on how would those work compared to li-po's??

MMDooley, Should work great!

Coolhand - I was joking! But, if you're serious it would be pretty nuts!

Alex, what will be the price on these for say every thing? ( 2 battery packs with the little things needed)

The packs are going to be $99.99 each. The LVD which you need is $25 per side of the truck (because you need one to manage each battery), but I may work out a deal if you buy all of this together. I have to talk with Apogee before doing that, as they are very strict about dealer pricing... For now, shoot me a PM, and we can discuss pricing...
Alex

Well the only reason for the 30 instead of 36 is the rpm limit on esc. :002:
I have some 26 cells packs now that are currently being used. If you charge all of the bateries up and run them can't you just use one LVD.
It will read 2-10s lipo.

No, you would need 2 (1 per lead going into the ESC). The leads pulg into the Dean's going to the Speed Control. It would be much safer to wire the packs in series and then attached the LVD on the bridges to the ESC(if you know what I mean lol). Basically, its a set of leads that senses voltage which you put on the Male Dean's plug coming from the ESC and is wired into the reciever. Simple to do, very hard to explain!
Alex

While it may be "safer" to wire 2 LVCs for 2 packs, it really is unnecessary. If the cells in the 2 packs aren't closely matched, then that means that the tolerances in the manufacturing process are low (like with cheap Chinese cells), and the cells aren't quality. One LVC is all that is needed.