ESC Battery cutoff settings

#61

Oh yea that’s a relatable scenario :joy::joy: I’ve been skating for 10 years so I just dont get tired, I can skate up hills for miles and miles. This electric skateboard build just gonna be a “congratulations you’ve been going for this long you deserve to just enjoy the speed without pushing”

Yea that’s all I was worrying about is the voltage going down when I’m not using it so if it’s not pulling a lot of voltage then there’s nothing to worry about. For fusing the charge port, I’m using a 2A charger, would 10A or even a 4A fuse would be good?

#62

what battery pack?

what settings did you put as well?

#63

have you hear of this amazing function called

:sparkles:auto_shutoff :sparkles:

granted idk what escs are and aren’t compatible, but i should at least throw it out there

#64

I’d use a 7.5A 58V fuse

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#65

I’m not making assumptions about how the shutoff happens. No ESC model was ever mentioned.

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#66

touché

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#67

The RC enthusiasts recommend 3.5v as the point that battery health is at risk. I’ve got that as a cut off end but as I have the alarms too I’m happy with that as I can monitor and be aware of cell variance. 3.7-3.8 seems a sensible level to have cutoff start if you want to have good power and then stop not too long after cutoff start but if you will be riding 10kms away from home and have a mid-low capacity you may want to ramp it up to 3.9 or higher.
@b264 , those charts look good, why do those values take such higher recommendations than most of sites talking about lipo rates? Is it a conservative approach or is specifically about esk8 and the rules are different?

#68

Not sure, but my personal experience with lithium batteries is that the #1 killer of a battery is running it all the way to empty in a multiseries configuration.

I’d love to hear from others.

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#69

like mine?

have 6 lipos

2 sets of 3 in seris in parallel?

#70

lipos experience bounceback tho, so what the voltage it goed to in use is not a reflection of it’s state at rest

i’ve ran my packs down numerous times to close to 3.0 per under use, but by the time i set em ip to charge, they’ve all recovered to ~3.6-3.7

only timeni recommend you raise the cut off is if you usin some sketch lipos or sum, cause they can be more unpredictable

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#71

Does a BMS keep lipo cells balanced during use or is it just managing that aspect during charge functions?

#72

i think it only does during charging, or maybe while it’s sitting around if you don’t bypass it probably

#nobmsgang

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#73

During the end of the charge cycle only is when a normal BMS will balance.

But watch out because there are BMSs out there without balancers, these are nigh useless for us. Make sure it has a listed balance current or don’t buy it.

#74

Does the LTT BMS have a balancer?

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#75

ya that’s fine

smart LLT bms?

(lttstore.com)

#76

image
image828×1792 1.82 MB

This is the one I got, it’s smart and has Bluetooth

#77

It balances at around 50ma, very slow but works

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#78

As long as it keeps my batteries in check then that’s all that matters :+1:t3:

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#79

It’s been keeping all my boards in check at a very high tolerance.

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#80

@b264 since you are the expert on lifepo4 batteries long-term, what cutoffs do you have? What damages the cell, and what’s the healthy way to give them a long life?
3.55v down to 2.6v?

got a 16s5p for info