Any electronics hobbiests want a project?

[MakeMePower]

Well, I think the one does not have to exclude the other and two options are better than one and better than none.

For prototype, sure, might be 3D print custom. But is 3D printing on bigger scale economically viable compared to finding already existing that fits?

expecting to sell thousands are we?

 

[wpns]

A couple of random thoughts:
How much current do you need to boot up a typical battery?
How about a current-limited power supply that ramps up until the battery wakes up?
Once the battery is awake, can you charge your jump-starter off the battery?

 

[MrSparkle]

expecting to sell thousands are we?

Not necessarily. I have never used 3D printer. Just imagining that printing "only" 100 or even 50 pcs might become tedious?

 

[MakeMePower]

Not necessarily. I have never used 3D printer. Just imagining that printing "only" 100 or even 50 pcs might become tedious?

not really once the design is finished and run through the slicer, its just a couple button presses. depending on the size, several can be made at a time. 50 to 100 is not a lot.

 

[zcskywire2]

A couple of random thoughts:
How much current do you need to boot up a typical battery?
How about a current-limited power supply that ramps up until the battery wakes up?
Once the battery is awake, can you charge your jump-starter off the battery?

1. No idea, 1A is probably more than plenty to unlock the BMS. Different BMS's do weird things though. You'd most certainly need a traditional charger ready to support.

2. That is the exact goal

3. With the IC selected that is possible as it is a 2 Switch Buck Boost controller (Boost in one direction and Buck in the other) We will figure that out later if we actually allow that.

 

[MrSparkle]

not really once the design is finished and run through the slicer, its just a couple button presses. depending on the size, several can be made at a time. 50 to 100 is not a lot.

Well, then it all sounds promising!

Comes to mind. If already 3D printing, some logo would be nice/fun?

"Made by DIYsolarforum.com"
?

 

[MakeMePower]

Well, then it all sounds promising!

Comes to mind. If already 3D printing, some logo would be nice/fun?

"Made by DIYsolarforum.com"
?

well considering the design guy doesn't know how to write the code. I'd say we are still dead in the water lol

 

[Rednecktek]

This project is sounding way more complicated than I expected. Code? Custom PCB's?

Glad I asked for help!

One request though if/when someione starts printing, please please DON'T make it blue!!

 

[MrSparkle]

please please DON'T make it blue!!

Rainbow colored with unicorn logo?

 

[SparkyJJO]

Rainbow colored with unicorn logo?

Everything seems to be RGB LED lit these days...

 

[MakeMePower]

the real question is what are people actually willing to pay for something like this. This already looks to be about a 50 dollar item

 

[sunworshipper]

I'm wondering if someone on here who plays with electronics should start building & selling battery-waker-uppers. Maybe something using an 18650 or two with an adjustable/programmable boost converter with settings/marks for 14.2v, 24.4v, and 48.8v with a momentary contact button. Connect a couple alligator clips, set your battery voltage, push the button. Power from the battery gets upconverted to $n voltage, BMS sees a charge voltage and wakes up.

Bonus points if it's USB rechargable and can be user changed between voltages for those of us with multiple voltage systems (i.e. I could wake up my 12v battery then turn a dial and wake up the 48v battery) easily.

Yes/no? Way more complicated than I think? Doesn't come in blue?

get yourself a hand crank DC generator (12V or 24V). Attach a pair of alligator clips to its output. When you need to wake up a BMS, attach the leads & crank. Here's a 15V generator

 

[MrSparkle]

When you need to wake up a BMS, attach the leads & crank.

Imagining watching some one doing it. Waking up a High Tech battery with Low Tech solution aka MacGyver style. I kinda like the idea too.

 

[Rednecktek]

the real question is what are people actually willing to pay for something like this. This already looks to be about a 50 dollar item

In the solar world that's not horrible. If we made it blue we would have to charge $150 for it.

Besides, I've already offered the first $100 towards R&D and prototyping.

 

[Rednecktek]

Imagining watching some one doing it. Waking up a High Tech battery with Low Tech solution aka MacGyver style. I kinda like the idea too.

How heavy would a 48v cranker be?

Do you slow crank for the 12v battery then really go to town to wake up the 48v?

 

[MrSparkle]

Do you slow crank for the 12v battery then really go to town to wake up the 48v?

A little sidestep off topic.
On my custom DIY E-chopper, I am planing to build a pump with a small pressure container, connected to the drive chain. (Under the battery pack.) The idea is to try and test to offer simple bike repairs downtown center in the cities. (Summer vacation country tour.) And when needing to pump up a tire, I just jump up on the bike, crank it some (MC style bike stand) and when pressure rose enough I just pump up a bike tire. Think of it kinda steampunk wacky fun.

 

[sunworshipper]

In the solar world that's not horrible. If we made it blue we would have to charge $150 for it.

Besides, I've already offered the first $100 towards R&D and prototyping.

hand crank generator in blue! - https://www.amazon.com/Portable-Hand-cranked-Generator-Emergency-Dynamotor/dp/B07T1MF5VC

 

[Rednecktek]

hand crank generator in blue! - https://www.amazon.com/Portable-Hand-cranked-Generator-Emergency-Dynamotor/dp/B07T1MF5VC

I'd love to see someone crank that thing hard enough to wake up a 52v battery!

 

[sunworshipper]

How heavy would a 48v cranker be?

Do you slow crank for the 12v battery then really go to town to wake up the 48v?

sorta yes. the voltage induced is proportional to the rate at which the magnetic flux changes within the windings. higher rpm = higher mag flux change rate.

 

[zcskywire2]

We will stop here for now because its work time now, Big sad. At about $10.60 in bom cost right now with a few of the pricier components remaining. Most of the cost is the DC-DC controller at $6.11

 

[BarracudaBob]

https://www.aliexpress.us/item/3256806860722901.html

 

[Rednecktek]

We will stop here for now because its work time now,

You want to stop a solar forum project for your day job? Where are your priorities man?!

 

[Luk88]

99% of people that need it will find the battery in their battery jump starter dead when they do.

Before jumping head first into designing, how about the design requirements are established first?

Specifically, how much current and for how long? I seriously doubt it is going to be more than 0.1A for 1s. So we're talking 5W of power... For 1s. That is possible with an alkaline AA let alone lithium.

Why go down the rechargeable route, when there is almost no rechargeable batteries that can sit in a drawer for a year or two and still perform?

If the assumption of 5W for 1s is even close to correct that would be 5J of energy needed for one jump start. A typical alkaline AA battery has 9kJ to 10kJ of energy. Let's say you waste half of it. It still will last for 1 thousand jump starts.

 

[42OhmsPA]

Why bother with AA? 9V would be much easier. Would be great for 48V systems, 6 in series will get you 57V when they are new.... Dang it I only have 3 left.
3 in series would work for a 24V system.

 

[Bananaman321]