2S lipo with stock?
- Thread starter BriaN
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i_r_beej
Well-Known Member
- Messages
- 993
The discharge rating only indicates how quickly the battery can provide power to the electrical system. A higher discharge rating won't overwhelm the car. However, batteries with higher discharge ratings WILL cost more.
To answer the OP question: The AMP MT and DB do NOT have an ESC that has built in low voltage protection. To safely run a LiPo battery in the AMP you will need to buy a low voltage alarm. These are inexpensive little gizmos that connect to the balance lead on the LiPo battery and will sound a LOUD alarm once the battery drops below a preset voltage. Once you hear the alarm, stop driving and recharge the battery. I have the Venom "Low Voltage Monitor"- and it works quite well and can be configured for various voltage levels. You can find cheaper LVM devices on Ebay - for just a few bucks - but I can't speak to the quality of those devices.
LiPo batteries, unlike NiMh or NiCd, do NOT respond well to discharging below a certain point. Discharging a LiPo below 2.8V per cell can RUIN the battery! You can run a NiMh completely flat, but not a LiPo! There is some debate about what the lowest safe discharge voltage is for a LiPo, but most agree that 3.2V or 3.4V is a the best, safest cut off point. In fact, in practical application, you'll notice a distinct drop off in performance about 3.7V so you'll want to stop and recharge well before battery damage anyway.
I have two Venom 7.4V 4000mAh batteries. I can run my AMP full throttle for about 40 minutes and the battery will have only discharged to about 3.8V. And, unlike a NiMh, LiPos typically don't get so hot during discharge (maybe 90 deg F) so you can put them back on a charger immediately. A NiMh gets hot and needs to cool down between charge discharge cycles.
To answer the OP question: The AMP MT and DB do NOT have an ESC that has built in low voltage protection. To safely run a LiPo battery in the AMP you will need to buy a low voltage alarm. These are inexpensive little gizmos that connect to the balance lead on the LiPo battery and will sound a LOUD alarm once the battery drops below a preset voltage. Once you hear the alarm, stop driving and recharge the battery. I have the Venom "Low Voltage Monitor"- and it works quite well and can be configured for various voltage levels. You can find cheaper LVM devices on Ebay - for just a few bucks - but I can't speak to the quality of those devices.
LiPo batteries, unlike NiMh or NiCd, do NOT respond well to discharging below a certain point. Discharging a LiPo below 2.8V per cell can RUIN the battery! You can run a NiMh completely flat, but not a LiPo! There is some debate about what the lowest safe discharge voltage is for a LiPo, but most agree that 3.2V or 3.4V is a the best, safest cut off point. In fact, in practical application, you'll notice a distinct drop off in performance about 3.7V so you'll want to stop and recharge well before battery damage anyway.
I have two Venom 7.4V 4000mAh batteries. I can run my AMP full throttle for about 40 minutes and the battery will have only discharged to about 3.8V. And, unlike a NiMh, LiPos typically don't get so hot during discharge (maybe 90 deg F) so you can put them back on a charger immediately. A NiMh gets hot and needs to cool down between charge discharge cycles.
I haven’t looked but my Redcat came with that jumper. Not my Amp. It’s basically a fail safe in case your alarm falls off or gets disconnected. It runs so long there isn’t a big risk and you can peak under the body and see what it reads any time.
Whatch your motor temps, it’s hot out. You can smoke a motor running 20 minutes plus on a high drag surface and/or heavy throttle.
Whatch your motor temps, it’s hot out. You can smoke a motor running 20 minutes plus on a high drag surface and/or heavy throttle.
Djones48
Active Member
- Messages
- 44
Hmm..I will have to investigate further. The guy at the hobby store said the car won't even move unless I change the jumper settings. If he is just blowing smoke I'll have to call BS but I watched a YT video on it and if its just a voltage cut off system I'll just leave it as is and go with the voltage alarm.
No you just check it. A little infrared heat gun but my LHS doesn’t have any in stock. You can also use your finger... if it’s too hot to touch for more than a second it’s too hot.
On the stock motor and electrics it will work fine. Just check it once in a while and don’t do something like run it full throttle for long periods on grass - that’ll drive temps up. When I’m running one I like places that have some rough terrain but also some flat smooth stuff so I can run it fast and yet ease off the throttle to let it cool. Plus I stop every 10 minutes or so and just touch the ESC and motor to see how hot they get.
I decided to put the 550 19 turn brushed from the Volcano into the Amp and put the 3,300 kv brushless setup in the Volcano. The 550 is 10cm longer but otherwise fits. That should have plenty of torque and handle anything that little Amp can do with no problems. The Volcano on a 3,300 kv brushless and 3S will be fast.
I um, might have just ordered an Arrma Notorious 6S ?
On the stock motor and electrics it will work fine. Just check it once in a while and don’t do something like run it full throttle for long periods on grass - that’ll drive temps up. When I’m running one I like places that have some rough terrain but also some flat smooth stuff so I can run it fast and yet ease off the throttle to let it cool. Plus I stop every 10 minutes or so and just touch the ESC and motor to see how hot they get.
I decided to put the 550 19 turn brushed from the Volcano into the Amp and put the 3,300 kv brushless setup in the Volcano. The 550 is 10cm longer but otherwise fits. That should have plenty of torque and handle anything that little Amp can do with no problems. The Volcano on a 3,300 kv brushless and 3S will be fast.
I um, might have just ordered an Arrma Notorious 6S ?