LiPo cut off for Losi MRC esc

[nick c]

I picked up a Losi MRC from the swapmeet and am finally getting around to getting it set up. The guy had it set up on a 2-cell 1350 mah lipo. I bought a charger from the shop out in tacoma, and he told me to be sure I set up a low voltage cut off for the ESC so i don't ruin my lipo.

Reading online it doesn't sound like the Losi esc has a low voltage cutoff built in. Anyone care to recomend a good one? Or is it really not needed?

 

[pokey]

I know very little about these things so far. Butttt Sean told me not to get the battery (lipo) below the 3 volts (by leaving it plugged in) or the battery can explode upon recharging. He said there are some tricks to rechargong but still risky. My car(sc10 4x4) has the esc that has the cut off so it cant be run to low. Risk would be if the car was left on or the battery left plugged in. I would find a cut off or change the esc to one that has the setting.

 

[super samurai]

does it have the stock speed control? I am wandering cuz I picked one up just after the swap meet, and I know nothing of these little guys

 

[slednecks1124]

Ditch the stock speed control and go to either a castle creations mamba micro pro or a novak Mongoose brushless setup. I run the mamba micro pro with a losi insane 370, it has great low end control and tons of wheel speed. I don't personally care for.novak products which is why I didn't go with the Mongoose setup, a lot of people run it and it also has great low end control with lots of wheel speed (crazy speed on 3 cell lipo).

WWW.allerc.com has prob the best prices on the mamba micro pros, its a great speed control and u can adjust everything like punch control, drag brakes, throttle curve, breaking curve and much more with the castle link (adapter that hooks up to computer)

U should be able to use discount code "yahoo10" on www.allerc.com for 10% off your total order also.:awesomework:

 

[JOOP]

Ditch the stock speed control and go to either a castle creations mamba micro pro or a novak Mongoose brushless setup. I run the mamba micro pro with a losi insane 370, it has great low end control and tons of wheel speed. I don't personally care for.novak products which is why I didn't go with the Mongoose setup, a lot of people run it and it also has great low end control with lots of wheel speed (crazy speed on 3 cell lipo).

WWW.allerc.com has prob the best prices on the mamba micro pros, its a great speed control and u can adjust everything like punch control, drag brakes, throttle curve, breaking curve and much more with the castle link (adapter that hooks up to computer)

U should be able to use discount code "yahoo10" on www.allerc.com for 10% off your total order also.:awesomework:

I have the Castle creations USB link with the Sidewinder motor in my 1.9 Losi. It's pretty control able. You can set the throttle curve to however you want.

I just got my 1.9 Losi a few months ago, gone through 3 lipo's so far. I have gave up for the most part right now. Tired of buying batteries. So the Losi is up for sale or trade.

 

[slednecks1124]

I have the Castle creations USB link with the Sidewinder motor in my 1.9 Losi. It's pretty control able. You can set the throttle curve to however you want.

I just got my 1.9 Losi a few months ago, gone through 3 lipo's so far. I have gave up for the most part right now. Tired of buying batteries. So the Losi is up for sale or trade.

The micro sidewinder is.basically the same as the micro pro besides without.the casing.and heat sink, that's why the micro pro can handle little more power.

If u have gone thru 3 Lipos u have something going on, should be an easy fix. Lipos don't like to be charged at a high current, don't like to be discharged beyond I believe 3 volts per cell and don't like heat or to be badger against rocks.I've had my crawlers for about two years and have never ruined a lipo besides from smashing it on rocks during a comp which caused it to swell, even then it still worked but I decided to toss it. I buy my Lipos for my mrc pro from hobbypartz.com, they r gens ace 450mah 2 cell Lipos and they r only like $3 each, I don't need large batteries as I mainly comp so I just use one battery per course. If u have any questions let me know I can try to help out so you don't have to sell ur crawler, Lipos can be sensitive if not cared for properly, there was a thread over on rccrawler.com where I learned all about.them ill try to dig it up later cause it has lots of good info on lipos

What type of Lipos u run? What kind of charger? What settings r u charging the battery at (voltage and current)? What do u have ur lipo cutoff set at?

 

[JOOP]

What type of Lipos u run? What kind of charger? What settings r u charging the battery at (voltage and current)? What do u have ur lipo cutoff set at?

I've ran LOSI 7.4v 600maH, and gone through two Parkzone 7.4v 800maH. I'm using a Traxxas 2-cell/3-cell Lipo balance charger. You just plug it in and wait for the light to turn green. It's suppose to turn off when it's fully charged but I'm not thinking it is.

 

[slednecks1124]

I've ran LOSI 7.4v 600maH, and gone through two Parkzone 7.4v 800maH. I'm using a Traxxas 2-cell/3-cell Lipo balance charger. You just plug it in and wait for the light to turn green. It's suppose to turn off when it's fully charged but I'm not thinking it is.

I wouldnt trust a charger like that, I like to be able to visually see.the voltage, current and how much mah the battery is taking in each charge. If u have a volt meter try checking the voltage after a charge to see if its getting charged.are the batteries swelling up or do they just stop working? Please explain a little more in depth.

 

[JOOP]

I wouldnt trust a charger like that, I like to be able to visually see.the voltage, current and how much mah the battery is taking in each charge. If u have a volt meter try checking the voltage after a charge to see if its getting charged.are the batteries swelling up or do they just stop working? Please explain a little more in depth.

The last two swelled up. This last one I'm sure if it is or not.

 

[PHILLBILLY1]

I have an external Novak 2cell lipo cutoff that you can have if you need one. :awesomework:

I am running 3 cells, so I will no longer need it. Let me know:awesomework:

 

[JOOP]

I have an external Novak 2cell lipo cutoff that you can have if you need one. :awesomework:

I am running 3 cells, so I will no longer need it. Let me know:awesomework:

Yeh that would be cool. What's the advantage of running 3 cell?

Sent by that electronic thing we call a phone...

 

[CHOP SHOP]

I did not like running an external lipo cutoff on my rigs for two reasons.

1. Added complexity and more parts to fail.

2. I dont like to run down to the cuttoff point.


A lipo will not punish you for not discharging it like a nimh/nicd will. A lipo actually likes to be "topped off".

I like to run my lipos down to about 3.5V instead of at 3.0V. I think 3.0V is right at the damage zone. If you pull a heavy 4x4 rig one last pull it can pull that lipo from a safe 3.1V a cell to under 2.5V under heavy load and instantly the lipo cuttoff will kick in. Now turn the rig off and back on to reset the ESC cuttoff and then gas it and you will notice the rig has DROPPED in power massively compared to that last lap even without tripping the cuttoff because your holding it and no load is really present like when its on the ground.

At 3.5V my car still has full power and lots of punch. It takes me less time to charge back upto 4.20 and be back in action.

Plus if I leave the track with a couple dead (3.5v) packs in my box, I dont have to sweat charging them that night because they have a decent amount of juice left.

Remember lipos dont like to be stored fully charged either. 60-80% capacity is best for storage.


I bought a little screen that plugs in to my balance plug on the battery and flashes 3 different readings (2 cell). Fist it flashes the total V, then cell1s V, then cell 2s V, then back to the total and so on.

It was about $20 and has 7 prongs on it so it will work with 1-6 cell lipos. It will flash out as many cells as you have plugged into it.


I just plug it into my car and ONLY MONITORS voltage not switches/cut it like a cuttoff does. I just run the rig by me every 6-10 laps or so and glance at the little red digital readout.

I have also seen buzzers, I like that idea too.

I dont remember the name but this is the one I have here.

[YT]http://www.youtube.com/watch?v=9XKDyP5M_x4[/YT]

 

[nick c]

It was about $20 and has 7 prongs on it so it will work with 1-6 cell lipos. It will flash out as many cells as you have plugged into it.


I just plug it into my car and ONLY MONITORS voltage not switches/cut it like a cuttoff does. I just run the rig by me every 6-10 laps or so and glance at the little red digital readout.

That sounds like what I need. I'll track one down.

 

[slednecks1124]

Brad is right, going with the 3 volts per cell rule is kind of risky, I have my lipo cutoff set at 3.4v per cell just to be safe. I've over discharged a few packs before from leaving the truck on after.hitting the lipo cutoff, some say it will decrease the life of the pack by discharging it too much but I cycle out my lipos after a while since they r only 3-6 dollars each for my application.

I personally don't care for the external cutoffs, like brad said it adds more cluster into the wiring and another.thing to possibly fail. There are many perks when switching to an aftermarket speed control such as lipo cutoffs, input voltage capabilities (some allow upto 6 cell lipo, no need for 6 cell in crawler though, I prefer 3s), drag brake settings, punch control, brake curves, reverse throttle limiter, no neutral time limit between forward and reverse, motor timing, throttle smoothness, and much more. Buck up and buy a nice esc its well worth the money, even just the smoothness and drag brake settings in a crawler make a huge difference.

The digital displays are okay but most crawlers have a painted body which would not allow u to see it unless it was exposed somewhere that it would probably get.crunched by the rocks. hobbyking.com sells the digital displays for.cheap if that's the route that fits ur budget. I come from the comp scene where every little.bit of an advantage helps so spending money on quality electronics doesn't bother me, but for people who use these things for.backyard bashing it can be tough to justify spending $75-100 on a speed control, just do whatever works for u and that's my $.02:redneck:

 

[PHILLBILLY1]

Yeh that would be cool. What's the advantage of running 3 cell?

Sent by that electronic thing we call a phone...

More cells = More power :awesomework:

On the other hand, More power = More breakage :redneck:

 

[slednecks1124]

More cells = More power :awesomework:

On the other hand, More power = More breakage :redneck:

That's why I usually run 3 cell, its like the happy medium and still plenty of power

 

[hlb3]

I never bothered with a lipo cutoff on my MRC's, I've got a bunch of batteries for it so i just swap them out regularly, its pretty easy to tell when they are starting to run low. Ive got my scaler cutoff set at 3.3v if i remember right, don't think I've ever had it kick on since I'm running 5000mah packs in that thing.

 

[PHILLBILLY1]

I never bothered with a lipo cutoff on my MRC's, I've got a bunch of batteries for it so i just swap them out regularly, its pretty easy to tell when they are starting to run low. Ive got my scaler cutoff set at 3.3v if i remember right, don't think I've ever had it kick on since I'm running 5000mah packs in that thing.

Yep. Once they start to lose power, I pull the plug. I usually have a few extras ready and charged.