Don’t think anyone is saving packs from thermal runaway but loop key is good if your transmitter or receiver start acting wonky and decide not to go idle or brake when you need to stop. Basically don’t want to end up flying through an intersection out of control because I don’t like the look of a loop of wire. Only place I see it really helping with preventing fires is stopping one from over discharging and then attempting to charge cells that have gone over the voltage cliff.
Measurement with my custom receiver hooked up and the newer metr Bluetooth module. 26.34 mA in case it’s hard to read.
On my battery this means if I had it fully charged at 5000mAh it would be 200 hrs or about 8 days of idle before it would be entirely drained and I would have wasted one cycle on the batteries. To put it another way every 8 days you are losing a cycle just from idle power… You have roughly 300-500 cycles per cell so would take 2400-4000 days or about 10 years if all the cells did was idle and get recharged but given you are riding daily I imagine that means recharging every day as well in which case you probably really only have a year (maybe 2 if you recharge every other day) before the cells will be under 80% their original capacity. The drain every 8 days means in a year you lose about 45 cycles just from idle power. In two years with that loss you’ve sacrificed 90 of 300-500 cycles or 1/5-1/3 of the usable cycles have been wasted.
Granted above numbers are all run with my relatively small battery.
Once people have had some hands on time testing these and they’re proven I might be more inclined but XT-90 loop key or antispark bullet are pretty safe options in terms of not failing or doing something unexpected (my loop key hasn’t once tried to jump out or plug itself in and when I take it out the circuit turns off every time)
Not a good argument - xt90s have failed (see @whitepony) and are not as bullet proof as you want them to be. Also this thread is not about which switch is the best but convince @never4getf150forums to use one.
So if it makes @never4getf150forums use a switch the push to start one will be better than nothing.
Well I’m not arguing for Xt-90s just the most reliable solution in my mind right now. Didn’t see the issue white pony had but only issue I’ve personally experienced with them is when I didn’t plug it in all the way to the high current draw went through the resistor in the start of the plug and it fried in there (had to use pliers to yank it out).
If it turns out Martin’s thing is ultra reliable and never fails after people have been reporting back for a year or I’ve had my own hands on time I can report about with it I just don’t want to suggest it (no offense intended)
I am trying to get it as close to perfect as possible, but of course the true test will be the first batch to ship out.
And I understand how important it is to make it reliable, since some want to use the switch without any push button at all. I will do my best to test the switches as much as I can, the last thing I want is to be responsible for someones board to break or get damaged.
My thoughts on this subject, based only on your testing:
If you actually ride your board every day and use a small lipo you could still be treating it better by turning it off when not riding it. The drain when not riding the board won’t affect your range by that much though. If you have some hugeass batterypack like 30q 10/12s 3/6p the drain shouldn’t be noticeable at all anymore. Also the cycles of your battery don’t matter anymore. It would take decades to wear it out.
What I would be more afraid of is the electronics wearing out. I don’t think the most esc’s are made to be always on.
I’d agree with most of what you said. I should add I have a 10S battery so 25mA x 10 x 4.2 = 1050mW or 1.05W about 1W so looking at it in terms of Wh I have a 185Wh battery so can run for about 185 hrs idling if full and basically lose 1Wh per hr out of the battery. If you are at 12S the idle amperage should be lower probably where the 20mA figure on the other forum came from (and or lack of receiver/telemetry).
Regarding the electronics it’s just the arm processors running when you’re getting an idle signal and I don’t think it would be an issue. Not sure what cpu utilization looks like on the vesc really but imagine it isn’t super stressed.
There most likely has never been a thermal runaway with the loopkey removed and the board not in use. I view the loopkey more as a measure to isolate the battery from all potential load for safe storage. It’s a preventative measure rather than a reactive one. Anyhow, gl with your builds brother.
it’ll take about 35 days to completely drain my 10s5p 30q pack.
that’s 1 cycle a month, 12 charge cycles/year lost out of about 1,000 cycles total.
i plan to replace my battery at least once every 2 or so years for the next best cell. so it won’t be much of an issue.
“Don’t think anyone is saving packs from thermal runaway but loop key is good if your transmitter or receiver start acting wonky and decide not to go idle or brake when you need to stop. Basically don’t want to end up flying through an intersection out of control because I don’t like the look of a loop of wire.”
would this happen even with a gt2b? i thought this sorta problem was only prevalent on cheap remotes that you have to manually reset/re-trigger after every start.
If the wrong pin comes loose from the wrong component pretty much anything can happen depending on which pin on which component. I’ve generally heard positive things about the gt2b but I don’t have personal experience with it. In the transmitter the trigger could mechanically break or the potentiometer or hall sensors used for detecting position could have problems that develop over time or come from changes in environmental factors around the components between calibration and usage. The receiver can have pins come loose from the RF chip and the main mcu on the receiver may or may not be programmed to handle any given pin on the RF chip coming loose.
Have personal experience with things going wrong while developing my own remote so there’s definitely good reason for me to not trust them. That said even if you are using a known good remote there are lots of things that can go wrong not to mention most of our parts are customized or custom made (one offs without much testing)
Basically nothing is full proof, but having some sort of emergency cut off button or loop key on anything with this much power and remotely controlled still makes sense to me even with a ginormous battery.
Some people turn boards off to save the batteries. I would turn my off to save my self the trouble of having a house fire.
I mean come on, are you really going to let that pack full of angry chemical energy pixies with some DIY style wiring be protected only by some transistors made in god knows what place on this earth?
