haymitch

Greetings all. I am new to the forum. I have been running a Nitra Evader for a few years, but finally got tired of the fuel, noise, etc.... I now have a 4x4 Slash VXL. Anyway, I am wanting to get a second battery. I am military and live in military housing so Lipo batteries are not an option since they are banned in military housing. I want to get the most bang for the battery. I am looking at an 8-Cell 9.6V DTX 5000mAh Hump battery. Iam curious if this would be a good option for me. I mainly bash and race on the dirt roads and fields around the housing area with other military people, so none of us can use lipos. Any ideas on a good battery for both speed and run time?

Secondly, I am looking at getting the wife a car. She wants something that can bash around the yard, race around the dirt, and maybe do some trach racing in the future (we are overseas and there is a great track nearby). I was thinking about an SC10, Arma Fury, or possibly the rustler, she does not want a slash. Anyone have any preferences or suggestions?

Foxy

Have you considered LiFe batteries? All the benefits of lipo, none of the hazards, although they are slightly lower voltage. It's a real shame that you are forced to use NimH or NiCd.

If LiFe is still not an option, then the DTX batt you mentioned is a decent choice.

Get the wife a Jammin SCRT10 with a Castle SCT 3800kv combo, put a 15 tooth pinion on it and use the same batts you are using. It's a bulletproof car in the same class as the slash, with lots of options, but very little that needs changing out of the box (the OFNA eccentric motor mount is recommended). The roller comes with a clear body you can paint pink with flowers lol. All in with servo etc, it'll work out a little bit more expensive than buying an RTR, but you'll have a top truck with good stuff in it. It'll be more economical in the long run.

snir2001

My Feedback: (1)

Check this out,
http://www.hobbyking.com/hobbyking/s...arehouse_.html
http://www.hobbyking.com/hobbyking/s...ePo4_Pack.html

Both are LifePo4, not Lipo.
It's the best choice for you in terms of power to weight and price.

The Mad Modder

Where do they get the name "lifepo"? It says "life" right on the battey.

snir2001

My Feedback: (1)

Life is the short for Lifepo4, that is the chemistry

bigcam406

just wondering,can those batteries be purchased with the traxxas connector?

haymitch

Great advice everyone. I like the idea of going with the Lifepo batteries. I found quite a few options and the good part is they seem to come with adapters for all the major connections! Now I just need to decide between 9.9v 2600mAh or 6.6v 3000mAh. I am new to the electric side of things, so I have some research to do. I checked out the SCRT10, nice car, but she spotted an Arma Fury, the purple one, and she really like it, so I think my input may be overridden. Luckily the Arma is brushless ready, so I may just get her that, let her drive it for a bit, learn, and then upgrade to brushless. I was doing tons of research on a car for her, and was overridden because she took one look at the Fury!!! Oh well, as long as she is happy.

phmaximus

Lol

OWNED

Foxy

You should look at the higher capacities really, 4000mAh and up.

haymitch

So, like I said , coming from nitro, I am new to the world of electric cars. I am going the LiFePo4. I am looking at a 4200mAh 4S2P 30c LiFePo pack. I read somewhere that this battery will exceed the max voltage of the stock esc on my Traxxas VXL 4x4. I know very little if anything about batteries, and I know even less about LiFePo4 batteries. So, will this work or exceed the max volts of my stock esc? If it does exceed my esc, what would someone suggest? I plan on upgrading my truck eventually, but I am not at that point just yet. Secondly, how to I add a traxxas plug to this to connect it to the slash? Sorry for all the questions!

Foxy

LiFePo4 has less voltage per cell than lipo, but not so much that you can add a 4th cell unfortunately. The VXL is rated for 12v max and at 3.3v per cell (as opposed to 3.7v per cell for lipo), 2S is 6.6v, 3S is 9.9v, 4S is 13.2v.

3S at 9.9v (more when fully charged) will be ideal for that system, it'll give you a good middle ground between 2 cell lipo and 3 cell lipo.

This is the battery I'd recommend for you... http://www.hobbyking.com/hobbyking/s...arehouse_.html

haymitch

Great, Thank you so much. I just ordered the battery you linked to. I am brand new to the battery world of r/c and stationed in Germany, so trying to figure all this out, without a local english speaking hobby shop to go to and chat with the people there, I have a steep learning curve, lol. I appreciate all the patience and help in the forums here!


On a side note, I see this battery comes with a 5mm bullet connector. What exactly do i need to plug this into my Traxxas Slash? Do I need to splice and solder on a traxxas male plug? Do I need to change the Traxxas female on the car itself? I have heard of Deans connectors, do i need to just change everything over to that and if so, HOW?

Eman77

I have a few questions in general:

1) Why isn't LiFe more mainstream? I almost never hear it talked about on these forums, so I really don't know any of the pros/cons vs LiPo.

2) This one is a comment. Does "haymitch" really like the Hunger Games, or is it just a coincidental name?

haymitch

1) Well, I never heard of LiFe batteries before this forum either. That being said, I was a Nitro guy until a few weeks ago, and Lipo is not allowed where I live. I thought Nimh was my only option until I asked here on the forum.

2) My wife is a hunger Games fanatic, and well, I read the books after she insisted I do, and well the name Haymitch for some reason stuck in my head.

Eman77

That's cool, I'm reading book 3 now. Good read.

Eman77

So your battery will have 5.5 mm bullets, and needs to plug into the ESC. Traxxas ESCs come with their own Traxxas connectors. So you will have to either change the ESC connector, or the battery one.

Personally, I like to leave the battery one alone when possible (I've changed them before, no worries, but I've also nearly shorted a pack out due to carelessness).

To do this, you'd need the appropriate bullets for the ESC - males I presume, as I assume the battery is using females, which is standard. To do that, you cut off the ESC connector, strip the wire, and solder it to the new 5.5 bullet males - then shrink wrap the exposed stuff, and you're good.


You could change the battery connector instead, or change both to Deans, but to me it seems changing the ESC only is easiest. But you'll need to buy bullet connectors for it, and solder, shrink wrap, and a soldering iron if you don't have them.

Foxy

1) The voltage is wrong. It has inconvenient steps for the way ESC limits are designed.

By the way, haymitch, female on the battery, male on the esc! Be careful!

Eman77

Interesting. Makes you wonder why the heck it exists, doesn't it?

Foxy

It's much safer, more environmentally friendly and longer lived (more cycles) than lipo. I believe. lol. Someone feel free to correct me. In any case, for our OP here, it's the ideal solution to a problem, so it's just as well they do exist! Besides, you can always compensate for the lower voltage by adding a tooth to the pinion, the lower voltage would make the motors run cooler, so adding a tooth would cancel it out. At least in theory.

Everlastingboost

My Feedback: (1)

This! I just bought a slash looking to switch to lipo what do i need?

Foxy

A female traxxas connector, a 30W+ soldering iron, some solder, and some soldering ability or a friend with some.

Everlastingboost

My Feedback: (1)

Thanks!

bigcam406

i have a question.im wondering what the difference is between a 1sp and a 2sp if the batteries have the same voltage ie. 9.9volts.is it the amount of cells in parallel? thx

Foxy

Correct. There is no tangible advantage to either configuration (2s2p vs 2s1p for example for the same overall ratings will perform identically).