MeasurementGrand879 t1_jaejr09 wrote on February 28, 2023 at 9:32 PM

Reply to Google is rolling out fall detection to all Pixel Watch users by prehistoric_knight

YOU’RE FALLING! - watch Thanks, I know - me

MeasurementGrand879 t1_j919ncs wrote on February 18, 2023 at 1:47 PM

Reply to Hyundai and Kia cars could be stolen with just a USB cable by Sorin61

Ohh, please report on other news from the summer of 2022

MeasurementGrand879 t1_j621cdm wrote on January 27, 2023 at 3:40 AM

Reply to Donald Trump allowed back on Facebook and Instagram, Meta announces by esporx

Good, I just quit following my normal clown group.

MeasurementGrand879 t1_j29at6e wrote on December 30, 2022 at 4:09 PM

Reply to Does the extremely large dentist office off 65 between Ozark and Springfield creep anyone else out? by hannye14

New business in town? It’s gonna be a dentist or a bank. But no, this doesn’t creep me out.

MeasurementGrand879 t1_izaodjm wrote on December 7, 2022 at 6:44 PM

Reply to Ethereum’s energy switch saves as much electricity as entire Ireland uses | The success of The Merge concept may now serve as a roadmap to enable a switch from Proof of Work to Proof of Stake in Bitcoin. by chrisdh79

What a weird way to compare energy usage or savings. I use a lot of energy. Oh? Do you use as much as Ireland? Is that common knowledge? Would even the average Irishman or Irishwoman know how much energy that is?

MeasurementGrand879 t1_isemxf0 wrote on October 15, 2022 at 11:51 AM

Reply to comment by Felaguin in Not at all a "Hands on" person but looking to change that, need help with battery math. by FUCKPUTIN2022LOL

Edited to fix the typo.

MeasurementGrand879 t1_isd9p17 wrote on October 15, 2022 at 2:02 AM

Reply to Not at all a "Hands on" person but looking to change that, need help with battery math. by FUCKPUTIN2022LOL

Batteries are very unforgiving. You cannot turn them off and if you make a mistake, there is a lot that can go wrong. With that out of the way, you should start small and learn as you go. There are a lot of tutorials online for building battery packs. To answer your math questions, battery cells in series add voltage, cells in parallel add current capacity. To get 12v (14.8v) you would put 4 cells in series (positive of one cell to the negative of another). This gives you a battery of around 3ah at 14.8v. You would then put 67 of these 4-cell batteries in parallel (all end positives to all end negatives). This yields 268 cells as you calculated. You will need a BMS and possibly cell monitoring for over/under volts/discharge as well as temperature monitoring. How portable do you want this? An AGM or lead acid battery is way more forgiving and tolerant to incorrect charging. You can find similar 12v batteries of many different chemistries for a similar or lower price than you will spend building it. Good luck. Edit: changed a series to parallel. Edit 2: just as easily as it was to make that typo, it is to make a mistake with a battery pack. Start small for sure. Lithium chemistry batteries can be monsters.