Freenove 4wd car with Raspberry 4 won’t boot up from batteries but will when plugged in

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We have been building the 4wd freenove car with a raspberry 4. We purchased two Samsung 18650 batteries.

When we try boot up from battery power the red led light turns on on the pi. However the green ACT led doesn’t or barely lights up and we get no action!

If we plug the Pi in (while mounted and connected to the freenove car) it boots up no problem.

What could cause this? The SD card works (evidenced by booting when plugged in), and we have red led power light when powered via battery but it won’t boot!

Thoughts? Are my batteries did? They are brand new!!

Thanks Saulpi-4ShareEditFollowCloseFlagedited yesterdayasked yesterdaySaul1133 bronze badges New contributor

• 1How are your samsung batteries wired to the freenove car and Pi? Post a photo. – CoderMike yesterday
• 1Ya, we would need to see how these are wired, and if you have a regulator in use, how that is wired. Nominal voltage for those are 3.6V so if you are using them in parallel, I doubt there is enough voltage to boot. If the batteries are in series with no regulator, you would have 7.2 Nominal which is a little high, and those cells can be as high as 4.2 each, so 8.4 which is too high for the Pi. So you really should be running these in series with a good 5v regulator to bring the voltage down to the right range. – Chad G yesterday
• 1Ok I will it is built into the actual car so it is a full kit. Trying to figure out how to add a pic – Saul yesterday
• 1I have added an image of the back of the car. The battery system is on the actual car. As mentioned the Pi shows a red led when we switch it on just won’t boot up! (Unless we plug it in!) – Saul yesterday
• 1The car comes directly from the freenove 4wd smart car kit we didn’t do any of the battery wiring and the pi is getting some power because of the red light – Saul yesterday

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2 Answers

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Your pink batteries might be fake.

I googled the FreeNove 4WD datasheet which says the following about their LiPo batteries requiring discharging current > 10A:

1. 4WD Smart Car Kit for Raspberry Pi 

... Both flat and button top 3.7V 18650 batteries with discharge current >10A.

... For 18650 capacity, it should be 2000~3500 mAh. A bigger capacity may be fake.

References

(1) Freenove 4WD Car Kit for Raspberry Pi [Overview] 27,622 viewsOct 18, 2019

(2) Freenove 4WD Tutorial for 4WD Car Kit FNK0041 4,957 viewsMar 9, 2021

(3) Freenove 4WD Chapter2 Assembly & Chapter3 Test Freenove 4WD Pi Car 6,545 viewsAug 20, 2021

(4) Freenove 4WD Smart Car Kit for Raspberry Pi 4 B 3 B+ B A+, Face Tracking, Line Tracking, Light Tracing, Obstacle Avoidance, Colorful Light, Ultrasonic Camera Servo Wireless RC – Amazon us$70

(5) Freenove 4WD fnk0043 Tutorial pdf – FreeNove

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