Granite Help with low battery voltage

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kinaj

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Hi gentlemen. I'm already desperate. I have a one-way motor Arrma 550T (consumption max 17A). For that I have an ESC Hobbywing 1060 (60A). It happens that at 6500 mAh battery the ESC limits my power to 50% after about 7 minutes of driving and at 4500mAh after about 9 minutes (ESC when falling below 6.5V limits the power to 50%). I haven't done it yet and I can't handle it. Before that I drove without problems 25min on 6500. When ESC limited my power, the 6500 still had 65% capacity but only 3.74V per cell. Please don't know what could be behind such a rapid voltage drop?
It's only been happening for the last few days. I will be grateful for any advice.
I apologize for my English ... I'm from Slovakia :)
 
Have you changed anything recently? Maybe something in the drive train is stressing the motor/esc and draining more power.since the same thing appears to happen across different batteries I'll assume you've checked that your battery cells are good on all the batteries you've used? How are the temps of your motor and ESC after this happens? There are a ton of things that can cause your system to kill a battery quick but let's start here ;)

I had similar issues when I went 3s on my Senton Mega, turns out the dean's connector I used for the esc to battery connection was limiting power transfer and it was stressing my motor and esc. They would get super hot and it would shut off after about 10 minutes of run time.
 
Have you changed anything recently? Maybe something in the drive train is stressing the motor/esc and draining more power.since the same thing appears to happen across different batteries I'll assume you've checked that your battery cells are good on all the batteries you've used? How are the temps of your motor and ESC after this happens? There are a ton of things that can cause your system to kill a battery quick but let's start here ;)

I had similar issues when I went 3s on my Senton Mega, turns out the dean's connector I used for the esc to battery connection was limiting power transfer and it was stressing my motor and esc. They would get super hot and it would shut off after about 10 minutes of run time.
Have you changed anything recently? Maybe something in the drive train is stressing the motor/esc and draining more power.since the same thing appears to happen across different batteries I'll assume you've checked that your battery cells are good on all the batteries you've used? How are the temps of your motor and ESC after this happens? There are a ton of things that can cause your system to kill a battery quick but let's start here ;)

I had similar issues when I went 3s on my Senton Mega, turns out the dean's connector I used for the esc to battery connection was limiting power transfer and it was stressing my motor and esc. They would get super hot and it would shut off after about 10 minutes of run time.
Hi, the engine is quite warm after 7-8 minutes of driving, but I can keep my fingers on it. For comparison, ESC is only slightly heated. The tension on the cells was the same 4.19 before and 3.47 after the ride. I changed Dean's connectors for EC3. I didn't change my car as such if you mean gears or something else.
 
Hi, the engine is quite warm after 7-8 minutes of driving, but I can keep my fingers on it. For comparison, ESC is only slightly heated. The tension on the cells was the same 4.19 before and 3.47 after the ride. I changed Dean's connectors for EC3. I didn't change my car as such if you mean gears or something else.
It might be the esc can't handle the battery, assuming the batteries are 2s (since you're still using brushed) but what is the c rating? It has to be at least 35c and with a 60 amp esc I wouldn't go higher than 80c (that may be too much for the esc). I found 50c batteries worked well on my 60 amp esc's while the 35c were barely enough to have fun on...
 
Hi, the engine is quite warm after 7-8 minutes of driving, but I can keep my fingers on it. For comparison, ESC is only slightly heated. The tension on the cells was the same 4.19 before and 3.47 after the ride. I changed Dean's connectors for EC3. I didn't change my car as such if you mean gears or something else.
I have a BH Power 30C battery that should be ok. The problem will probably be in my connector (it was my first attempt at soldering). Red looks fine, but black probably doesn't.

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That connection looks pretty bad, you could try repairing it to see if that helps. When soldering are you using lead alloy or lead free solder? Lead alloy is much easier to use than lead free, uses a lot less heat to melt so it makes it much easier to make solid connections.

Only mentioned the c rating because the mega esc is rated for 35c minimum but if it was working then your solder joint is likely the culprit.
 
New connection. I'll try it today and see if it help. I will also check the connector on the ESC. I use lead alloy.
The fact that this is what is causing my problem also suggests that the flashlight always behaved differently when charging. Sometimes she jumped quickly from flashing red to orange and then to green. Sometimes charging on 4 amps to full took 25 minutes, sometimes 45 minutes.

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New connection. I'll try it today and see if it help. I will also check the connector on the ESC. I use lead alloy.
The fact that this is what is causing my problem also suggests that the flashlight always behaved differently when charging. Sometimes she jumped quickly from flashing red to orange and then to green. Sometimes charging on 4 amps to full took 25 minutes, sometimes 45 minutes.

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So you're saying your battery is charging super fast (the part about the flashing light)?

Have you checked your individual cells? If you have a smart charger with a digital display you should be able to see the voltage of each cell that way. If not then you need to get a bolt meter and check each cell using the balance port (smaller wires on the battery). It really sounds like the battery is the problem...
 
The cells should be ok. Measurement before and after driving (4.2 / 4.19 and 3.74 / 3.74V). That was probably just my subjective impression (super fast charging). Today I charged 6500 for about 45 minutes and 4500 for about 30 minutes (4A). Now the question arises whether this is normal time as the battery (6500) is have after driving for approx. 65% of the capacity but the voltage was only 3.74V per cell. I think the problem is in the ESC. This rapid loss of voltage is happening on both batteries.
 
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I agree, if the battery cells are holding a charge then it's probably the esc has gone bad. Each cell shouldn't be discharged below 3.2 volts max, this is what the low voltage cutoff prevents, and max charge will be 4.2 volts per cell. If after a run it is still at 3.7ish volts you lvc is kicking in too soon. You could try checking the esc's programming to see if it is set to a high lvc and change it to see if that helps at all. I've got most of my esc's set to 3.2 to 3.4 volts but yours may have somehow changed to a higher lvc...
 
This ESC is cheap and does not allow programming. I'm trying to complain about it. I will not buy new ones and I will try to convert Granit to 3S. At least my time will pass faster before Typhon 3S V3 comes to Slovakia :)

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These are what I run in my Senton Mega conversion (3s), using the higher kv motor makes it possible to run almost stock gearing. I did replace the spur gear with steel but it was running on the stock plastic without issue on 2s, just wears fast on 3s ;)

120 amp esc: https//www.amazon.com/gp/aw/d/B07WHCLTYQ/ref=ppx_yo_mob_b_inactive_ship_o0_img?ie=UTF8&psc=1

4300kv motor:
https://www.amazon.com/gp/aw/d/B07BGWRFGX?psc=1&ref=ppx_pop_mob_b_asin_title

Spur gear:

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I want something like that too. One more thing occurred to me. I recently exchanged the Spektrum kit for a DumboRC with gyro. Could it have something to do with it?
 
I want something like that too. One more thing occurred to me. I recently exchanged the Spektrum kit for a DumboRC with gyro. Could it have something to do with it?
You may need to recalibrate the throttle, on most esc's there is a second button next to the on/off switch. If yours has this button you'll want to turn off the car, turn on the radio then press and hold the button while turning it on. Once you turn it on release the button, pull back all the way on the throttle and hit the button while holding the throttle back. Then push forward on the throttle all the way and hit the button again. Then just turn it off a d it should be calibrated. If this fails to help I think your gonna be in the market for a new esc.
 
I came to the conclusion that I did not know mathematics. 3.74 + 3.74 is 7.48V. So ESC has no reason to limit performance. I don't understand it at all ...
 
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