Loop Key + Charge Only BMS = DEAD Battery

welp…i built my brother a budget board a couple years back, and at that moment i guess I wasnt forward thinking enough BUT he left the key in which killed the battery…

i built it charge only so he could “grow” into the pack later on and upgrade to better vescs that could handle more amps…

at any rate, for the future aside from a charge/discharge bms option is there an option im overlooking for some kinda fail safe in case this happens again?

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Trampa VESC hibernate + optional loopkey that stays in all the time.

Idk why other manufacturers haven’t figured out how to do it yet.

Use one of these in the board, it will beep really loud when it falls under a programmable voltage, plus a couple of other things


Robogotchi has a voltage alarm that has saved two batteries for me.


Make it big enough so you literally don’t have to worry about that…ever


This is the solution :joy:

This is the way.

…or…you know…pay attention to the large dangerous package of chemical energy that’s sitting inside your home…where you sleep.

Just a thought.


i guess he’ll just have to be responsible more next time lol… i started him with some cheap 4.1x vescs and hoped he would have bought my unity or FS as an upgrade (and. on/off switch)but hes comfy where he is with those and his budget board…

off topic… i havent had to source cells in a while but is it me or are 30qs hella expensive right now? what did i miss??



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COVID stoped cell production big company’s bout up stock meaning less over flow for us to buy

Actually big companies stopped ordering cell production because “covid will mean we sell less electronics” then covid sells way more electronics and the cell fabricators have already lowered capacity because of the smaller orders so there is a shortage

There is huge back ordered on cells Samsung is only supplying to the huge orders. Also take in to consideration there has been several reports of the explosion of electrical Vehicles that will soon be exseding the supply and deman for battery’s. I’d say EV battery’s are a parity sound investment over next few years. Elon musk has realised this and invested hugely in making his own battery’s for his tesla. All in the aid to avoid the choke point that’s conning

Yea I know only the larger orders are fulfilled :sweat_smile:
There is a shortage because all the large companies initially placed smaller orders speculatively.

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I had a 13s8p battery with the little black groundwire attached on the wrong side of the loop key. When I unplugged the loop key I could tell the LLT BMS was hooked up wrong because it was still reachable via BT… the weirdest part was that the app only read the values in the first few p groups. They got progressively smaller and most groups were reading zero volts. I freaked out until I realized the cells were fine.

They are, and they aren’t even that good when you compare them to newer cells that cost less, like the p26a

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So, since there is such a demand for cells again, companies are putting big orders again and many companies investing in battery technologies, is it likely that we will see “abundance” of cells in year or two?

In part.
The demand surge is actually signifigantly larger than the actual demand.
You’ve got a company like Nissan ordering cells, but they might be ordering from another company that makes the battery modules. That company is ordering extra because they’re suffering through the shortage too, so they want extra stock. That company might be ordering its supplies from other suppliers, who are also ordering extra. That ordering extra goes all the way down to the lithium, copper and raw material mines and processing companies, by which point the actual amount needed by Nissan has been massively overinflated.

The companies along this chain who must invest millions into factory infrastructure know this is the case (i.e Silicone fabricators, cell manufacturing plants) so they aren’t actually going to build capacity for a continuous production of the inflated demand. So its going to take a while for the demand to settle back down to normal (And the longer there is a percieved shortage, the longer the problem of people ordering extra exists)

I don’t think we’ll see an abundance of cells which lowers prices any lower than 2018/9 prices, but the high demand has opened the door for companies like Lishen, Molicel, BAK and DLG to sell way more and invest into better cells which are safer and much more usable in our application. Without the spike in demand its debatable how long these companies would have taken to begin making cells on par with Samsung and LG Chem, but as of right now they’re all really close and in some cases ahead (See Linshen’s 5000Mah cell or some of BAK’s new 21700s for really good performing Chinese and Tiwanese cells). So not really a lowering in price because of an increased supply (not yet at least) but more competition.


Old post I know but I can always reach my LLT even with my loopkey unplugged, it keeps the BT module on