My electric lawnmower has 2 batteries with an auto switchover feature… Why can’t I have this on my eboard for long range journeys?
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It’s certainly possible technically but…just curious…what do you see as the advantages over a single larger pack?
Having two packs would require additional monitoring and switching electronics. This adds cost and requires extra space.
A single larger pack would also run cooler and more efficiently (due to lower current per cell) and not have the power losses through the extra electronics. This would result in longer range.
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108 20650 cells between my legs is already pretty girthy.
Adding 96 more cells just for the occasional 60 mile ride would be killer for the daily zip.
I don’t love the idea of charging while riding either. Seems like you’d be putting a lot of heat and energy in and out of the pack.
Fastest and cheapest option is to open the enclosure and swap 2 wires but I’m lazy.
Maybe a dpdt switch between the 2 batteries and esc, mounted to the enclosure would allow me to flip a switch and have a full pack again. Esc might not be a fan of the quick power supply swap though.
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I used to have a shoei that did the same thing, it was the most comfortable helmet I’ve ever owned.
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I’m confused…I thought you were describing having two packs always in place and just having the electronics switch between them when necessary. Wouldn’t this mean those extra cells would always take up that extra room?
Or would you pull out one pack and put in the second? But if this is the case then no electronics is needed to switch between packs…hence my confusion. 
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I choose answer C, none of the above 
Ideally, I would keep the second pack in storage until I have an itch to go far. Then, I would strap it on top of my existing battery pack and set out on a long voyage.
I would normally just parallel the packs before setting out but the cell type difference (LG hg6 vs Samsung 30q), pack size difference (9p vs 8p), and age difference concerns me wrt drawing equally from each.
If I could put the 2 packs on a toggle switch, I’m thinking I could ride one pack until almost empty, turn the esc off for safety, toggle switch the input supply to the 2nd battery, and turn the esc back on with a new full pack.
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It already exists.
Here is a quick test by some guy
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Surprised I haven’t seen anyone rocking one here. Maybe the awkward minute or 2 when you hit a tunnel or other dark spot and it is still tinted is enough to dissuade.
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I have seen a few but they are expensive. The one Bell makes for my helmet costs as much as the helmet itself.
Sunglasses will do just fine in my case 
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Ahhh….okay, makes sense. 
Not sure you’re going going to find a high enough current rating for that toggle switch.
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weird but kinda useful idea, having an ambient light sensor that will trigger front light on when light level is below X
basically like car headlights when going into tunnels or something like that, yes, its a lazy thing when i can just bend over and click a button, but why not have it autonomous?
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I was using a “heavy duty” one on a scooter to fake a turbo mode before I found esk8. It would jump from the input supply from 36v to 48v (heavy ass SLAs 
).
It was rated at 20 A/125VAC. 10 A/277VAC and that would likely still fail on me.
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Looked into this myself, only way I can see it working is with discharge BMS’s on each pack and a big Schottky Diode, but then you have the volt drop over it.
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No I like this. I often lean down like an idiot and try to hit my lights around dusk. Front lights are fine but I CAN NOT make a straight line while adjusting my tail light.
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Interesting conundrum. Would this work? Both the xt90s are panel mount. Keep bat 2 disconnected until bat one runs out. pull out the loop key for bat 1 and connect the bat 2 into the second xt90s
thoughts @Battery_Mooch ? Would the positive of battery 1 being plugged in to the esc be a problem while battery 2 is connected?
If you only wanted one panel mounted xt90s and assuming your battery is top mount, you can wire battery 1 exactly like battery 2.
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idea expansion time:
- ambient light sensor for lights control
- car detection sensor for someone tailgating u (possible to detect motorcycle / bikes…etc)
- distance sensor to honk at cars if they are too near
my brain hurts
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Definitely.
DC current ratings for a switch are a lot lower than the AC ratings.
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Don’t know…probably not?
IMO it would be best to just use a dual connector setup for both packs and move the dual loop key from one pack to the other.
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Love the ideas but have a few thoughts…
Not triggering on passing shadows means having a built in delay but this will delay lights on when entering a tunnel or dark area. This might not be an issue but worth considering.
How can we prevent it from triggering when passing bollards, people, benches, etc.? Only activate if detection is solid for a period of time perhaps…one second?
How do we prevent is from triggering on other objects and people? Use a delay here too?
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The dunbar number theory. Do communities such as this in a way disprove it or prove we’ve evolved past it, biologically, technologically, the feedback loop therein, or otherwise? And furthermore, the shared ideas a group such as humanity or this forum agree upon as true, how would those affect a scientific community such as this? If astrophysics are in play you can deal with my shit too.
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