Thinking about going LiPo...Battery & Charger questions

[JeffEmbracedDC]

Aye, guys. So I am toying with the idea of going LiPo. I race a TC4 with a mamba max so I'm thinking I need a 2s config. I also run a brushless Hyper 7 that I would want to run on 4s. All of my battery mounts currently fit a regular sXs pack and I'd like to keep it that way if possible.

So basically I want to find out what kind of batteries are available, who makes them, what MAH, will they fit in my cars, how much are they, Can I put these in series to make a 4s pack, What kind of charging rate do you charge at, etc etc. Also what are the general ups and downs of using LiPo rather than NiMH

Also.. what's a good quality but economically priced charger (hopefully ac/dc).

What kind of $$ can I expect to spend on switching to LiPo?

Thanks!

-Jeff

[Stuart B]

I have a 2S maxamps 4000mAh for my MM 5700...really does the job. Even with my old brushed setup there was loads more punch. I have a 3s on the way from max amps.

Sorry if you know this already!

I think 1C is the max charge rate..bothing wrong in charging slower as far as I am aware.

You will need a balancer uinit (or a charger that balances), I use the astro blinky. Cheap enough and does the job. You don't have balance every charge, but every few is a good idea.

The Lipos are rectangular in all dimesipons if that makes sense. They don't have the circular sides like sub C. A 4000mAh is the same length and width as a regular 6 cell, it is shallower though, and lighter. The 3s is the same size as 6 sub C near as dam it, but again dopesn't have the circuler sides....so if you battery compartment is formed to the circular shaped sides, then some modding is required...the 2s may fit...but thats a guess. I think their 2s 6000 is about the same size as a 3s 4000, all the dimenions are on the maxamps site.

Use the cut off voltage on the mamba to avoid over discharge.

Don't leave the m unattended while charging. I am happy chargin mine in my room in a tin as long as I sit near by and keep an eye on things occasionally...while perusing this forum and ebay :). Don't let charge voltage go over 4.25V/cell.

Use deans connectors or something similar...not tamiya ones.

Might sound daunting to some, but I reckon you won't regret going lipo, the motor can only be as powerful as what the battery can supply....lipos are great at supplying :)

Edit not sure how my reply ended up 2nd, there was already a post by erik before I replied :)

Stu

[ErikRC10]

The best charger you can get for lipo without losing a limb is the Duratrax Ice. A very good company for lipo's is Maxamps (www.maxamps.com). The rule for charging lipos is 1C. for example if you have a 4800mah lipo pack one C is 4.8amps or for 8000mah pack would be 8amps and so on and so forth.

[Duster_360]

I use the Ice charger too. Apogeee recommeds the Ice as a lipo charger. According to one of their sponsored racers, Tim Mohr, its the safest one they have tested.

[JeffEmbracedDC]

Cool. Thanks, guys.

So can I put these batteries in series like normal? Let's say I got a few 2s2p packs and wanted to series two together to make a 4s2p pack. Is that fine and safe to do like normal?

So what are the best batteries to get? I have heard the orions are good.. some say the max amps..
which ones are better value?
are either of them more durable?
Does one have a hgher MAH rating than another?

Also.. for the Ice.. you need a 12v power supply, correct?
What's the least expensive (maybe an 8 or 10 amp) power supply?
Can the ice charger charge more than one pack at a time?
Can it charge different types of batteries at once? I think the super brain 989 or something has that kind of functionality. Thanks!

Hah.. so many questions.. Thanks, guys.

-Jeff

[Rufus]

I use a 13.8 v Pro peak "Ripmax" power supply rated at 20 amps. Its great, cheap (around 60USD, maybe less) and pretty light. And, no you can't charge one pack at a time with the Ice... However, if you want to charge 99% charge in 30 min. vs 1 hour get an apogee LiMn pack, those are rated for a 2C charge. I have two of them and they're pretty good. Heard those, the scorpion packs and the kokam cells (orion packs) are the best performers so far. I think the scorpion packs can also be charged at 2C but I'm not sure if they need a special charger for that.
Great to hear you're going lipo, you won't regret it. :wave:

[bdebde]

I really like the limn packs, 2C charge is nice

[Stuart B]

Cool. Thanks, guys.

So can I put these batteries in series like normal? Let's say I got a few 2s2p packs and wanted to series two together to make a 4s2p pack. Is that fine and safe to do like normal?



-Jeff

I am pretty certain you can series them as long as they have the same chrage state...check what the lasndspeed record boys are doing, they have 2s and 3s combinations in series.

Stu

[NORTEX-T1FK]

I just got my 6000mah maxamps 2s lipo and it is awsone. I charge it with an MCR 989. I can get about 30 minutes run time with a Novak 4.5 on my xxx-T. I've abandaned that though because I got tired of breaking it :mad: .

Now I'm just running an Orion 19T Element and it rips pretty good with the lipo. A little reverse and then forward will flip it on its back with 24/86 gear setup :D . Way faster than a Venom stick pak( :roll2: ) or even GP3300 pack I have.

[guver]

You can now get 5000 in one cell and it fits in where a subC pack does so that is the hot set-up.

[pinolelst]

You can now get 5000 in one cell and it fits in where a subC pack does so that is the hot set-up.
yeah except you need a 2 cell pack as a minimum ....

but you're right in that the new 5000 mah cells and some 6000 mah cells (I think) will fit in the stock battery location in most rc's.
heck I have a 4400 mah 3 cell that fits in my xxx-t with a little shoving ;)

pinolelst :wave:

[MartinRacing]

Alot of us East coast/ Charlotte NC area guys run the 8000 lipo MaxAmps.com...in the 10th scale electric trucks, and we run for 20 mins. We let the gas guys run with us if they want< lol>

I would not try to combine battery packs... not good.

You can use the astroflight 109 charger or the Ice charger.

Although we do run 20 mins, I run brushed motors with no problem, most of the guys run the GTB 5.5 or so, but they do thermal... I used to run brushless, I dont think they are any better. Until then...

[JeffEmbracedDC]

What are the dimensions of the 8000mah packs you speak of? Got a link? Thanks!

-J

[MartinRacing]

www.maxamps.com

[trxcrazy345]

super brain 989 and max amps has saddle packs with some good ampage i think you said saddle not sure though?

[kschauwe]

You can now get 5000 in one cell and it fits in where a subC pack does so that is the hot set-up.
Maxamps.com have 10000mah cells now.

[MartinRacing]

Maxamps.com have 10000mah cells now.

too big, although the 12000 will ! ( but still its too heavy )

[A Main Racer]

Anyone know if this charger is any good?
http://server3.rvmshop.net/images/PBC0006/01.jpg

[ronb]

Charger question - Duratrax Ice seems to be recommended here, but does it have balancing circuitry? From the jest I get, you should have some circuitry to charge each cell separately as well as have a cutoff circuit on your car to shut it down once it dumps. How important are these? How come chargers and ESC's aren't embracing these functions?
...Ron

[pedebasher]

I'd like to know that also ronb.

Last time I was going to get into lipo I got a little confused and frustrated as to what I really needed, so I gave up. Now, the reality has set in that NIMH sucks and I hate it. Anyway, things are making a little more sense now. The ICE charger if it will work, I am very familiar with as I once had one, great charger. As far as a LVC, if I get the mamba system I'm looking to get, it'll have one built in, so that's a done deal. Only 2 questions I really have now is:

1. Which pack would you buy for a stampede with a mamba 4600 or 5700 system, and how many would you need for bashing. I'm clueless on lipo, but guess i've figured out that 2s means two 3.7 volt cells and 3s means three 3.7 volt cells. That's all I know. LOL

2. I'm very unclear about this balancing deal. What do I need to do it, how often should I do it, and how do I do it???

thanks

[pinolelst]

I'd like to know that also ronb.

Last time I was going to get into lipo I got a little confused and frustrated as to what I really needed, so I gave up. Now, the reality has set in that NIMH sucks and I hate it. Anyway, things are making a little more sense now. The ICE charger if it will work, I am very familiar with as I once had one, great charger. As far as a LVC, if I get the mamba system I'm looking to get, it'll have one built in, so that's a done deal. Only 2 questions I really have now is:

1. Which pack would you buy for a stampede with a mamba 4600 or 5700 system, and how many would you need for bashing. I'm clueless on lipo, but guess i've figured out that 2s means two 3.7 volt cells and 3s means three 3.7 volt cells. That's all I know. LOL

2. I'm very unclear about this balancing deal. What do I need to do it, how often should I do it, and how do I do it???

thanks

2 cell lipo will be 7.4 volts nominal (3.7 x 2) and good cells will give you about 6 1/2 -7 volts at 100 amp loads. Thats better than most 6 cell nimh packs can provide.
3 cells = :eek:
When ordering packs pay attention to the size charts. Depending on how they're built they can vary a little in dimension between apparently same capacity packs.Make sure they will fit in your battery tray.You don't want your expensive packs flying out of the car in a crash becaause you stuck them in with masking tape or a single layer of velcro.Always strap over the top of batteries regardless of type.They don't know that they're heavy and like to fly if nothing's holding them down
I like the Astroflight Blinky balancer because it's cheap and seems to work well.I also have the thunder power 10 cell balancer and it works fine as well.I balanced all my packs when I first got a balancer and some were a little out as the lights were pretty busy flashing on and off as they did their thing but now I balance them about every 3rd run or so.It seemed if I did it more frequently the balancer was hardly working at all meaning the pack was still close enough to not need balancing then.Even every 3rd run might be a little excessive but gotta justify the purchase by using the darn things ;)
hope this helps

pinolefm1

[pedebasher]

Yes, that helps. Thank you! Trying to make note of all this. Will have more questions in a bit.

thanks!

[pedebasher]

I just made my own thread since I had a zillion questions and didn't want to hijack jeffs. Hope you guys don't mind. It's titled "lipo savvy folks please respond" as I'm sure you could figure out, LOL

[JeffEmbracedDC]

haha nah it's fine with me. I'm learning just as much from it as you. Thanks for all of your help, guys!

-J

[pedebasher]

That's cool Jeff! :) It's all confusing as heck and I didn't want to clutter your thread up. Feel free to jump into mine if any of my questions are the same as yours. Hope you get it all sorted out, hope I do to. I have a feeling these threads will benefit others as well. I'll quit rc before I go back to NIMH, I can promise you that much. If lipo is half as good as advertised, I'm sold. That and the fact that anyone who is negative about them, ususally doesn't own one or even know what they are talking about. Seems like nobody goes back.

[GearheadXNT2]

HOW DO YOU CHARGE A MAXAMPS LIPO ON AN ICE CHARGER? THERE ARE NO TAPS :confused: . please reply @ Ice charging a lipo :D

[guver]

It is charged thru the discharge lead (the 2 wire connector)

[dam3d]

http://cms.teamorion.com/orion/instructions/ori_fin_li_inst.pdf

[pedebasher]

delete please