Afraid of the unknown, LIPOS!
 

I am getting closer to taking the plunge into Lipos.
I was just wondering if I could get some pointers on what to get.

I have a Honcho, a Foff rig and an SC truck that I will be using them in.
I would like to get some units that would work in all three. Probably not ready for 3s though.

Please guide me wise members of RCC.

Doing a few searches will help out.

Do you have a LiPO capable charger & can it do balancing??
This is a must have, if not, there is a range of options, some can do AC or DC input, others are only one type of input.

LiPO's are not an issue if you excersize a little care.8)

be sure to buy a lipo bag for charging, storage and general piece of mind...it's saved a few already...

Well you could get a 2s 4600- 5000mah that would do well with the sc an possbly with the other rigs if you have the room, but lipos are fairly enexpensive so buying a cupple to fit your rigs should be no biggie.

I run a hyperion ES060s? Charger and it is super user friendly and does both AC and DC input sources. It is a little spendy at around $120 but well worth it as it has store mode and balances as well so your lipos last.

With some care lipo is just as if not more safe than your old nimh and nicd battries. Be sure to always balance the lipo, store at 60% of the batt. Capacity if not going to be used for more than a week, and store at a room temp. also be sure never to over discharge or over charge them. Follow these few tips and you'll have a happy, safe, and satisfying lipo experence!

hobbypartz.com is a good place to get cheap lipo stuff...just ordered my first lipo charger and lipo off there a couple days ago.

Check out the line of gens ace batteries from hobbypartz:

http://www.hobbypartz.com/gens.html

I run the 2S 5000mah lipos in my SC truck and couldn't be happier. They have a variety of batteries that will work in all your rigs. Also for a charger take a look at the Thunder AC6:

http://www.hobbypartz.com/thac6smbachw.html

It has a built in power supply and can charge just about any battery you can throw at it.

What speed controllers are you using in your rigs? They sound like they're more built for speed. Be sure that the Lipo's you buy are of sufficient discharge rates. 45C or higher should be good, but do the math first. Find the power current spec (constant and max if available) for your ESC's and match the Lipo to your rides.


-B

anything about 25C is sufficient for crawlers/scalers

If he plans on using the same batteries in all rigs, he's got to buy batts for the most power hungry. I'm guessing the FOFF pulls the most current. 25C batt in a FOFF that's pulling 200+ amps isn't going to last long. Of course that makes the BIG assumption that any of the OP'ers rigs pulls that many amps.

The Honcho is using stock Axial esc and 27t motor.
The Foff rig and the SC truck share a Dynamite Fuse brushless combo.
Gearing for the Foff rig is currently 15t/84t, and I think 15t/78t in the SC.
I might bump the gearing up in both rigs sharing the brushless.
Also have a few shelf queens, will Lipos work with anything that I use a Nimh in?

If the ESC you're using is this:
http://www.dynamiterc.com/Products/D...rodID=DYN3736C

then a 25C 5000mAh Lipo should be good. (ESC=70A continuous/100A peak)

With any other rig you plan on running Lipo in, make sure you have either an ESC that has a low voltage cutoff internally OR buy one that can be run externally. The LVC prevents the Lipo from being overly discharged.

So show me what FOFF is pulling 200 plus amps? :roll: Not theory mind you, real world eagle tree graphs from FOFF trucks.

Most monster trucks geared for 60 mph don't pull anywhere near 200 amps continuously.

The base C rating is for continuous and C rating alone doesn't give you the whole picture.

You have to include mah of a pack when figuring continuous amp ratings.

You could have a 40c 1000mah pack which is only good for 40 amps continuous while a 20c 4000mah pack is good for 80 amps continuous.

Anything that will give you 80 amps continuous will be plenty for most any rig. Most ESC's can't even handle 80 continuous. Only the heavy duty 8th scale ESC's get above 80 amps continuous.

Charge them in a lipo safe bag with a Lipo charger, Balance charge them every time and charge them at a safe voltage. 2s LIPO 2200mah I charge at 2amps


Also store them in some kind of metal fire safe box. I have mine in a metal box in my garage.

As long as you use a little common sense they are perfectly safe.

A few questions to ask your self and info:

1. Is your ESC Lipo compatible?
2. Do you know how to set up the LIPO cut off on your ESC?
3. Make sure the LIPO charger and battery have the same balancing taps.
4. Hyperion are standard balancing taps
5. Get a AC lipo charger so you can monitor the charging at home
6. Store your lipos in a dry cool place
7. Do not puncture the cells or they will catch fire
8. Do not over charge them with the wrong amps.
9. Do not short the battery out as well
10. Do not buy expensive batteries
11. Turningy makes great LIPO's and I have 6 of them over a year old and still going strong. http://www.hobbyking.com/hobbyking/s...brands_29.html
12. Do not let your Cells drop lower than 3 volts and 3.25 Volts per cell is a safer voltage
13. Each cell at full charge is 4.2 Volts so a 2s lipo is 8.4v fully charged
14. long term storage keep the cells at about 40-50%


That should be about it "thumbsup"

How long is "long term storage"?
Do lipos discharge over a long period of time.

Ex. My LHS recommends that I charge my nimh packs once a month or the voltage will drop too low.

Will this also happen w/lipos?

While I agree with your LHS on the NiXx self-discharging, LiPo's are a different story. They'll hold their voltage for quite a long time. I've heard that capacity gets diminished if you leave them sit for too long, but no idea how much capacity gets lost or if that capacity comes back with cycling. I've got some I bought last Christmas, and they remain largely unused (cycled on my discharger a couple times). My battery meter says the one is still at 46% charged and volts difference between the cells is still only .004 volts. The other one isn't far off from those numbers, maybe .011 between cells.

LiPO's have "almost" no memory effect over time, just don't let them get real low in voltage.
NiMH has "limited" memory effect over time.
NiCad has a greater "memory" effect over time.

All rechargable batteries will "self discharge". Temperature has a relationship on the rate of discharge. The lower the temp, the slower the discharge.

In some aspects, LiPO batteries can be "abused" more than other battery chemistries than others with little to no long term affect.
But, they can also create interesting fires if abused too much.:shock: