lipo compared to nimh?
 

So I was wondering how they compare. Is it a 5000 nimh and a lipo 5000 both have the same power out put just difference in run time? I am confused.

Ratings may make them look similar, but there's no comparison. Lipo holds voltage under load much better than NiMh, which gives you better performance. You'll see better run time from the lipo as well.

I was running 18th scales with gp1100 NiMh pacs - would get 9-12min runtime and got used to the pacs fading a little after the 1st few min run time. Switched to lipo, slightly bigger at 1300, but now get that fresh charged NiMh type performanace nearly all thru the pac. Huge difference in run time - the lipo gets 20+min routinely, have seen as much as 25min.

I recommend A123 Lithium batteries.
1. They have the safety of NiMH.
2. A123 cells are rated at 30C output continuous and 60C burst...that's higher than LiPo!!
3. You don't have to worry about low voltage cutoff like you do with LiPos.

Check them out at http://www.rclipos.com/A123_Packs.htm

So If i got some 5000 lipos the performance would be greatly more then the 5000 nimh batteries I have now? I am mainly looking for something for my E-Revo that would be a little better then what I have now.

Would thos 123 batteries work in the E-REVO?

Go to http://www.rclipos.com/RCL.html and click "Battery to Application Finder"

Does this help at all?

I run a123s also and their biggest prob is their physical size. Earlier I forgot to mention lipo is about 1/3 the weght of same size NiMh - you'll see performance increase from just the weight reduction.
Lipo is overhyped as far as danger is concerned. If you get proper charger and follow advice (no overcharging, no over discharging) use a lvc or eas with it built in to protect them from overdischarge, you shouldn't have problems. I've been using them for 4yrs now and havenever had a prob of any kind.

I built 5s1p a123 pacs with the cells side-by-side and they are far to large to run on my emaxx. I built some more as a dbl bbl shotgun style config with the 5th cell on top and I can run those, they'll fit with a little work. They weight a little less tha NiMh, but not signmificantly like lipo, so weight diff is not an advantage. I use the s-b-s pacs on my flm emaxx where I have a lot more room behinf the motor/trans in middle of the chassis, they're too big to run on the sides.

a123s also need a spec charger for charging. They can be charged at higher rates that lipo - I know plane guys charging them at 10C - lipo if you want teh best life from them, you charge at 1C. If you want to build your own a123 pacs, they are cheaper than lipo, if you're going to buy, there's noty much diff. a123s have reputation for lasting for many, many more cycles than lipo.

Is this is new E-Revo with the side batt compartments? The kind of lipo you'd be looking at for that E-Revo will easily fit. The a123s will not fit. Yes you will see a noticeable change in performance. I saw an instant performance gain in my 18th scales just by swithcing to lipo, remember your batts now weight ~2/3 less and voltage under load is much better.

I keep hearing everybody tell me that the LiPos hold their voltage under a higher load.. but I'm just not seeing it as a problem for NiMh. At our track we have a lot of folks with LiPo batteries.. all brands.. Orion, Trinity, TrakPower and others.. The consensus is that the NiMh have more punch in stock & mod... maybe we just have lots of really well matched packs... The weight of the LiPos might make you feel like they are giving you more power.. but its just the weight factor allowing you to get to speed faster.. I can definitely tell the difference practicing with my Orion 3200 in my stock buggy.. It flies farther over jumps and feels much lighter.

The runtime however is the biggest deal.. my 3200 LiPo has the runtime of a 4200 NiMh and my 4800 LiPo runs forever! lol...

If I get the lifetime out of these LiPo that I hear about.. then it's been a good deal! Other than that, I love'em!

Not to sure about these Lithium Ion (A123)packs.. they don't fit right and have a lower voltage than LiPo or NiMh.. Might be ok for bashing.. but not racing.

Have fun! Good Luck!

Jerome :tire::tire:

So for stock truck racing would you get a lipo pack?

Depends on if your track allows it... currently a no under ROAR rules... some tracks make you add weight.. The light weight is the only real advantage of sorts you get for running a LiPo in stock...

For the 2-3 times the price for a LiPo over a NiMh, I'd stick with the NiMh matched packs......


Jerome :tire::tire:

My track allows it and I dont have to add weight.

If you just run LiPos then it could give you an advantage... but also if your track is rough and drivers like to bump.. that is going to be a big disadvantage. Lighter vehicles take the brunt of a hack... they go flying out of control.. lol..

The lightness of the pack makes up for the lower voltage than a NiMh matched pack.. and if the lifespan of a LiPo is 2x or more.. then less hassle for you..


Jerome :)

Actually 'hard case' lipos are ROAR legal for 2008. Well assuming they are submitted by the manufacturer or distributor and pass safety checks. You do need to make minimum vehicle weight.

ROAR lipo rules in brief:

http://www.roarracing.com/downloads/...ipo_Reader.pdf

The approved lipo list:

http://www.roarracing.com/approvals/lipobattery.php

this is just like nimh vs nicad. could have same 'numbers' but too diff animals

R

I run Lipos in stock and mod classes. A really good NIMH may have more punch for about 30 to 45 seconds then they start to drop off. Lipo doesn't drop off. I run classes that have weight limits and must add weight to offset for the lighter Lipo. The Lipos still out perform NIMH. In addition, you can run the same batt and don't need a box full that you must charge, discharge, cycle, tray and then find they have dropped performance in a short time. Remember that a matched pack is matched for a very short time of use and then no longer are closely matched.

I have run an Orion 3200 in stock and Orion 4800 in mod for over a year and each is still balanced within .0001 volt without the use of a balancing charger, but I checked them at least every two weeks. Each performs like they did the first time I used them.

http://www.youtube.com/watch?v=A9ayuFBDrSg

A description of the video:
"A nail penetration test for A123's lithium cell vs. typical cathode chemistries in other lithium cells. We're using these in the VentureOne. Which would you want in your car?"