Noob question thread! 😀 ask your questions here!

kalebludlow · January 17, 2019, 9:49pm

Do you have any links for this claim

Not that I don’t believe you but its always nice to have it proven

Arek · January 17, 2019, 9:51pm

Don’t remember exact locations, you would have to google it yourself. Also it’s not like Tesla doesn’t charge to 4.20V for no reason…

b264 · January 17, 2019, 9:51pm

It’s one layer of protection, the charger also should not go that high. Also I want my battery to be able to be overcharged if it means my brakes keep working. I’d prefer a shorter battery life then streetface in certain circumstances.

Basically it is keeping you clear of “starting a fire” area but not ensuring you use it properly. It’s just a failsafe.

b264 · January 17, 2019, 9:52pm

Is it okay if we duckgo it instead?

Arek · January 17, 2019, 9:55pm

The problem and whole reason we have BMS is that you can’t rely on the fact that charger stops at X voltage which should end as 4.2V/cell because you can get all cells at 4.0V and one at 5V in fires and have same correct X voltage

kalebludlow · January 17, 2019, 9:57pm

You make the claim, burden of proof is on you. Don’t try and fuck around and argue points that you may or may not have any idea about.

Arek · January 17, 2019, 9:59pm

https://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries

thisguyhere · January 17, 2019, 9:59pm

4.35v that’s over volt protection, like from a regen system attempting to pump more voltage than it’s designed for.

given the right charger it’ll never over-volt, right, 12s charger max voltage is 50.4v…so it can’t go above that. now…if someone’s being funny and used a 60v cc/cv charger on a 12s or something, yea this bms will stop it at 4.35v, but don’t do that.

anyway, in esk8 application does not apply since both upper and lower voltage cutoff is configurable via vesc.

and yes, charging to less than 4.2v yields longer cell life. i’ve asked bestech if they can balance charge to 4.1v and was straight up denied.

Arek · January 17, 2019, 10:02pm

It’s from one of the 18650 cell datasheets, can’t find which one tho.

kalebludlow · January 17, 2019, 10:02pm

Thank you for that. Lots of useful stuff there. I think one thing to think about with this topic is that just because a BMS can go up to 4.35V doesn’t mean that it always will. Doing this a couple times over ~300 cycles will not significantly degrade performance. BMS protections are the exception, not the norm.

b264 · January 17, 2019, 10:03pm

@Arek BMS cutting off at 4.35V DOES NOT MEAN that you’re charging it to 4.35V per cell.

kalebludlow · January 17, 2019, 10:09pm

So have dozens of other people on the forum. This doesn’t make you a special snowflake. Please just move on

Mich21050 · January 17, 2019, 10:11pm

Its getting interresting

tardyparty7 · January 17, 2019, 10:12pm

Hi, I’m gonna build my own longboard deck to replace the deck for my first build. I’ve never made one before and I’ve done my research. Does anyone know where to get the right wood, preferably 1/8 Baltic Birch?

briman05 · January 17, 2019, 10:16pm

@Arek honestly there is no reason to argue with @b264 he is a debate Jedi. Some of his stuff I don’t agree with but he definitely does know what he is talking about with this.

thisguyhere · January 17, 2019, 10:29pm

(post withdrawn by author, will be automatically deleted in 24 hours unless flagged)

Arek · January 17, 2019, 10:31pm

Ok sorry, I won’t do that anymore. I’ll just flag you guys. If this is how you do it…

Ian-mountainboard · January 17, 2019, 10:43pm

has anyone ever used this esc. just wondering if it would be more reliable then some vesc’s

Hobbywing Ezrun MAX6 ESC (3-8S)

mmaner · January 17, 2019, 10:47pm

Ian-mountainboard · January 17, 2019, 11:05pm

Thank you wondering if 8s would be a bit to slow. although i can always change the gearing