4s 2p 8000mah 12c? lipo questions
 

I came across these 4s 4000mah 12c packs, and
so I'm wondering what happens to the "c" rating of the pack when I wire them in parallel? And will this be suitable for running in my savage?

The C rating stays the same, but the capacity will add up. So, in effect, you have a 4s 4p battery rated 8000mAh and 12c. Since the C rating doesn't change, you still get 12c, or 96A.

thank you for the quick reply, but the 12c still troubles me, I noticed that almost EVERYONE uses 20c and above, does the 12c contin. matter if I'm bashing with a SAVAGE?

The savage is a fairly heavy vehicle. That means it's gonna take a decent amount of power to run it at speeds ~30mph+ on 4s. Power= voltage X current.

That said, it's gonna require bursts well over 100A to push that Savage on 4s around unless you gear really low. If you were to run 6s on the right motor, current will be less for a given power. If you want 4s, then I would look for better batteries to be honest.

So, what is the WORST case scenario? Would this work? I know I get 96amps continuous, and 120a-136a burst possibly, depending on how well the packs are rated, I just dont know if these numbers fall into the right range...do you mind taking a look at the packs?:

http://i162.photobucket.com/albums/t...095-0-8888.jpg

"2 new ENERGY E.C. POWER 14.8v 4000MAH LIPOs. I think they are 12-15C contin . Neither has ever been used. They were just a bit big to fit in my plane. "


i am just getting a really good deal here, that's why I can't really let go of them, because if they work okay, it is totally worth it

Worst case scenario is that they will be overworked and puff after use. If they are a REALLY good price, it may be worth the risk. If you do, I would start with the lowest gearing watching battery temps and gear up slowly.

those numbers that I posted, 96amps continuous, and 120a-136a burst are these good numbers, or are they on the weak side? What's making you "hesitant" with these batteries? If those are good numbers, then, wouldnt this turn out alright? or is it the brand?

Usually with lipos, a deal that's too good to be true usually is. Some places overrate their cells. Anyone can list whatever current rating they want, but unless they also state what the voltage is under those loads, it is hard to tell if they are true/realistic ratings.

There are good low-cost lipo deals out there (TrueRC, Zippy) that people have reported to be very good for the cost. But at some point, someone had to take the chance to try them out before finding out they are indeed good product. I'm not saying those cells won't be good, but usually if it's a good deal out there, it's been found already.

I use them exact lipos...

What I can say is, for about $30-35, they work suprisingly well. Temps at the end of a run using my last setup before the motor melted (9XL 62/24 4s2p Gmaxx) were about 120*f or so, and they were hitting 3.0v per cell after about 10-15minutes of moderate bashing and speed runs on grass. They actually were only about 2/3rds discharged going by the mah I put back in, but they dont seem to hold their voltage so well under a reasonably large load.

I would say as an introduction to lipos and figuring out what kinda performance/speed/gearing you want to use, they work well enough, and in a lighter truck they would do even better, but for a heavy MT... you get what you pay for.

There are some very similar lipos on ebay right now rated for 5000mah 12c- I suspect they would be a bit better, and same kinda price range, but zippies arent much more, so its personal choice really.

what exact power e.c. packs are you using?

A couple last questions...

1) So would you recommend this Power EC 4s2p 8000mah 12C pack in a FLM Savage with a feigao 9xl motor? What exact battery did you test? Was it the same as the one I am looking to buy?
2) Just to get a good idea, about what run time do you think you would get with the Power EC 4s2p 8000mah 12C pack in your car before you hit the low voltage cut off when running these packs? What car was it in as well, and does it compare to my FLM Savage I have?

Thanks.

I would only reccomend those packs if you cant buy any other packs, Zippy or True RC would be better, but since the truck is heavy it is putting more of a load on your motor causing it to draw more amps...the batteries is one area I dont skimp on

My truck details are in my thread- see my sig.

I probably wouldnt recommend those batts though, not when there are zippies and swang lipos, or the truerc ones available.

azjc, would you think it is worth a try, if the packs are really cheap in price? How can I ensure that these packs will not draw too many amps, causing the run time of my battery to be shortened

Gear for about 30-35mph. That will lessen the load on the lipos.

Do you plan to still use the 2 speed and mech brakes? That will take some load off the motor and thus less load on the lipos.

96 amps cont wilth a 4s setup is ok, just do not try to gear the truck up to 40+mph. Converted savages are not the lightest truck. I run my savage with the 2 speed and mech brakes. I use a 14xl and 8s lipo. My packs are 3600 12c packs, older polyrc cells.

actually, the 3spd, but if I DO plan to use these crap lipos, I guess I will need to convert back to 2spd, and yes mech brakes, 9xl motor. So you seem to be doing fine, is that because of the HUGE voltage? So basically I will have to run my flm ext sav x ss at 35-40 /w 2spd, mech brakes to ensure good performance with these lipos?

again, just a thought: sorry for my curiosity, but if I absolutely HAD to, should I make the savage 1speed for better runtimes/less stress on lips?

IMO I would bite the bullet and buy better packs...it would be $50 you could spend towards a good pack, a 4s 5000 Zippy pack will be about $75....a 4s 5000 Enerland based pack is my first choice...I prefer flightpower

http://www.rc-monster.com/proddetail...P-EVO25-50004S

and Neu which are just as good and are a little cheaper

http://www.rc-monster.com/proddetail...eu25c4s5000car

You can still use the 3spd, and will have to run mech brakes with either the 2sp or 3sp. The shifting mechanism uses a one way bearing, so motor brakes will not do anything. You may be able to run the savvy at a higher top speed, as the addl gear the 3 spd offers will help. Basically the lower gearing in 1st helps the motor draw less current (amps) as it lessens the load.

See the above answer... A single speed will place more load than a 2 or speed, assuming that they are all geared for the same top speed. Just imagine trying to get a manual trans car moving in 4th gear, as opposed to 1st...

Yes, better lipos are great, but he should be ok with the ones he listed. He will need to start out carefully, and monitor temps on the lipos to make sure his gearing is not too high. Start with a smaller pinion and do some testing. Outside air conditions will have some affect on temps too, a hot sunny day, 90f and up, will result in much higher temps than a cool autum evening...