# Limiting current **URL:** \ **Category:** Speed Controllers (ESCs)\ **Tags:** basic-esc\ **Created:** [January 12, 2020, 2:18pm UTC](https://discuss.bluerobotics.com/t/limiting-current/6680 "2020-01-12T14:18:06Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![jamesssf](https://avatars.discourse-cdn.com/v4/letter/j/b77776/32.png) [@jamesssf](https://discuss.bluerobotics.com/u/jamesssf)\ **Post date:** [January 12, 2020, 2:18pm UTC](https://discuss.bluerobotics.com/t/limiting-current/6680/1 "2020-01-12T14:18:06Z")
I have four BasicESCs powering a prototype unmanned surface vehicle each with [1000KV motors](https://smile.amazon.com/gp/product/B01KZC9NVO/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1). During testing, I noticed the motors/ESC drew as many amps that it had available to it from my DC power supply. I’m planning on powering my whole USV with a [12V 36AH battery](https://smile.amazon.com/gp/product/B00K8E0WAG/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1). I’m worried the motors/ESC will draw too many amps and drain the battery too quickly. Is this a legitimate concern? If so, can the ESC’s limit current by a software setting? I’m open to suggestions. Thank you. ---
**Author:** ![williangalvani](https://avatars.discourse-cdn.com/v4/letter/w/6f9a4e/32.png) [@williangalvani](https://discuss.bluerobotics.com/u/williangalvani)\ **Post date:** [January 13, 2020, 12:30pm UTC](https://discuss.bluerobotics.com/t/limiting-current/6680/2 "2020-01-13T12:30:20Z")
Hi James, You can use the [MOT\_BAT\_CURR\_MAX](http://www.ardusub.com/operators-manual/full-parameter-list.html#motbatcurrmax-motor-current-max) parameter to limit the maximum current. Note that with the current implementation it may take a few seconds for the current to decrease and settle to your limit. ---
**Author:** ![jamesssf](https://avatars.discourse-cdn.com/v4/letter/j/b77776/32.png) [@jamesssf](https://discuss.bluerobotics.com/u/jamesssf)\ **Post date:** [January 14, 2020, 4:00am UTC](https://discuss.bluerobotics.com/t/limiting-current/6680/3 "2020-01-14T04:00:22Z")
Thanks for the reply but I’m not using Ardusub. I’ve tried googling this but either there isn’t any information or I don’t know what keywords to use to find it. ---
**Author:** ![williangalvani](https://avatars.discourse-cdn.com/v4/letter/w/6f9a4e/32.png) [@williangalvani](https://discuss.bluerobotics.com/u/williangalvani)\ **Post date:** [January 14, 2020, 7:13pm UTC](https://discuss.bluerobotics.com/t/limiting-current/6680/4 "2020-01-14T19:13:58Z")
What are you using? With ArduRover [you can set the target speeds](https://ardupilot.org/rover/docs/rover-tuning-throttle-and-speed.html). ---
**Author:** ![williangalvani](https://avatars.discourse-cdn.com/v4/letter/w/6f9a4e/32.png) [@williangalvani](https://discuss.bluerobotics.com/u/williangalvani)\ **Post date:** [January 14, 2020, 7:37pm UTC](https://discuss.bluerobotics.com/t/limiting-current/6680/5 "2020-01-14T19:37:37Z")
If you are using just the ESCs and a radio receiver, you could change the radio curve so the maximum PWM value is not as high. ---
**Author:** ![jamesssf](https://avatars.discourse-cdn.com/v4/letter/j/b77776/32.png) [@jamesssf](https://discuss.bluerobotics.com/u/jamesssf)\ **Post date:** [January 14, 2020, 8:26pm UTC](https://discuss.bluerobotics.com/t/limiting-current/6680/6 "2020-01-14T20:26:26Z")
I’m using a raspberry pi with a [hardware pwm controller](https://www.adafruit.com/product/815). ---
**Author:** ![williangalvani](https://avatars.discourse-cdn.com/v4/letter/w/6f9a4e/32.png) [@williangalvani](https://discuss.bluerobotics.com/u/williangalvani)\ **Post date:** [January 14, 2020, 9:01pm UTC](https://discuss.bluerobotics.com/t/limiting-current/6680/7 "2020-01-14T21:01:46Z")
Then you should probably just limit the maximum PWM you are sending. [The BlHeli\_S firmware doesn’t have any current limiting options](https://bluerobotics.com/wp-content/uploads/2018/10/BLHeli_S-manual-SiLabs-Rev16.x.pdf). ---
**Author:** ![jamesssf](https://avatars.discourse-cdn.com/v4/letter/j/b77776/32.png) [@jamesssf](https://discuss.bluerobotics.com/u/jamesssf)\ **Post date:** [January 15, 2020, 2:03am UTC](https://discuss.bluerobotics.com/t/limiting-current/6680/8 "2020-01-15T02:03:27Z")
Oh I see. I was over complicating it in my head as normal. Thanks for your patience and advice. ---
**Author:** ![williangalvani](https://avatars.discourse-cdn.com/v4/letter/w/6f9a4e/32.png) [@williangalvani](https://discuss.bluerobotics.com/u/williangalvani)\ **Post date:** [January 20, 2020, 9:00pm UTC](https://discuss.bluerobotics.com/t/limiting-current/6680/9 "2020-01-20T21:00:00Z")
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