DIY Battery Charger - Clever, Cheap & Easy

[@MrPizzaman09]

Lightbulbs are very useful. I used 10 300w bulbs in parallel as a Dyno load for many years of testing Briggs and Stratton engines for fuel efficiency. Used a 120v DC treadmill motor, which was perfect for voltage and rpm. I ran it up to about 20 amps at 120v.

[@istiakmahmud]

hi! I was hoping to make a 32650 lifepo4 12v battery bank and having issues making a charger for it. I lost a 30ah 12v smps after using couple of weeks and were thinking if i could use a 100/60 watt tungsten light bulb in series with 14.4v outout of the battery charger. The pack has a bms for lifepo4 and hope add active balancing in future. Will this Setup works for 12v system? Thanks in advance.

[@Iowa599]

I told you I was running a 150F capacitor & a group 9 lead acid battery in my daily driver (2001 Prelude), you told me to try lithium. After 11mo the $40 battery stopped holding a charge, but the 6mo warranty was expired. I finally went lithium, & replaced it with a NOCO NLP9. (I kept the 150F capacitor) $100 with a 5 year warranty, and it saved another couple pounds. This thing is so light, the box felt empty!

[@AlexLTDLX]

I love the lifepo4 battery I built for the LTD. I'm glad it's working out for you.

[@dennisford2000]

Used to trickle charge with a test light and a big shop charger

[@dennisford2000]

Common 1156 would limit to two amps roughly on a discharged battery. .4 on the taillight bulb/ other side of the 1157 . 104 was a bit under .2A

[@rossconverse9067]

Thanks!

[@AlexLTDLX]

Thank you Ross!

[@seamonsterco7570]

I use "used" HP server power supplies. Cheap and VERY powerful.

[@xxskizzumxx]

This is how us car audio guys charge up our billion farad capacitors without blowing up our car. Lightbulb is a great resistor

[@benstrait333]

So does the charger stop the charge when the batteries are full? Overcharging lithiums is no bueno...

[@AlexLTDLX]

As long as you have the voltage set appropriately for the battery yes. It's the combination of limiting the current earlier in the charge cycle and then having the power supply set for the maximum voltage that you want the battery to reach. This is fairly slow but it works and it's easy.

[@benstrait333]

@@AlexLTDLX Ah, ok that makes sense 👍

[@dennisford2000]

Hi watt bulbs less resistant and smaller bulbs less current.

[@dr_tal]

Wonder if you can use an old server power supply to charge a battery.

[@AlexLTDLX]

As long as the voltage is correct and you limit the current in some way - like I did in the video using a light bulb.

[@joshuastephens894]

Could this charge a 24v sealed lead acid setup?

[@AlexLTDLX]

Sure. Just make sure to set the voltage to something reasonable for that battery - I'd do something like 28 volts; if you want the battery to live a longer life, try 26 volts. It will be a bit slow, but it'll work.

[@jadz684z]

I have seen a lot of ideas and even hill Billy math work but this is a bright idea

[@shaner.5]

Hey alex and everyone else who might want a charger on steriods and on the cheap, look at the Riden RD6024 or RD6018 these things are great set the voltage from 0-60V and current 0-24A. its a simple device that just works to power anything in those ranges its hard to find something with that amount of real power 1440 watts and it will put that out continuously I ran mine for a week at 1100w no a flicker, between min and max set voltage was. .15v over a week. Worth I look I have burnt up so many others I have a drawer full of parts this one I have had going for almost a year, I can truely set it an forget about it and when i come back its doing what i told it to do.

[@AlexLTDLX]

That's a good tip - seems like a bigger version of the module I used in my bench supply. What are you powering it with?

[@dennisford2000]

Always feel great when they don’t have a website available when you input the name Riden or rd6018

[@shaner.5]

I was using hp server power supplies in series, (Loud 747 taking off) but replaced those with two Mean Well RSP-1500- 48's in series, I set the series voltage to 70 and there rated 32 amps so those drive more than its capable of but on the cheap the thrift store laptop power supplies works great too, its a step down so if i feed it say 40 volts and 4 amps I can charge at 10 volts 12 amps, so a power supply rated for 70 volts 26 amps is not reqired unless using at full pixes.

[@shaner.5]

I actually have two more mean-well's In a duracomm rack server model# RLP-6048M Its rated 48v 60a, (series) would trade ya for a vesc or brushless motor.

[@shaner.5]

@@dennisford2000 Yes very true but I wouldn't feed this thing with a mean-well rsp-1500-48 unless I really trusted it those are spendy 450ea. I have so many expensive desktop power supplies that haven't lived I decided to try something budget friendly. I use two at home and two at my shop and for the price of one hp supply I can buy 8 of these and did, haven't had to swap out one of them. If these last three years, (1 year in) I saved a grip the hp supplies go out 38 months in (36 month warrenty) and to repair is a flat 500.00 fee did that 5 times in 12 years. I need good clean power and thats what these things do period. I looked at these for 2 years and debated, when the 24 amp model came out I had to see and am glad I did, heck with bluetooth I dont even have to go look to change profiles or see % charged I can sit at my desk and watch alexltd videos!

[@dennisford2000]

How close to the math is the bulb to the wattage

[@AlexLTDLX]

Cold resistance is pretty much spot-on, but then of course the resistance increases as the filament heats up.

[@hyahmuleart7144]

So, yeah, pretty much you’re a team captain after an apocalypse and a worthy addition to my “voiceover with gesticulating hands” playlist. I really appreciate this shop talk format where you get an uncareful mix of how and why and a handful good keywords and concepts for further exploration. I hitted and smashed if for no other reason that to see wtf you are going to do with 12oz coke can batteries. Nice work.

[@derekfreeman3562]

What cells are those..where can i find them

[@AlexLTDLX]

Lishen 18ah LTO cells. They're pretty tough to find.

[@pauliemoto]

Chinese 10 amps😂😂😂 This is so cool, especially the fact that the light goes out when no current is being drawn and battery is charged.

[@icebluscorpion]

3:27 "those are Chinese 10 Amps so let's call it a real 5 Amps" that sentence killed me 😂its exactly what Chinese do when the measure their penis *Chinese measures 5cm* Oh 👀! 10 zentamita *Chinese writes 10cm for their penis length* 🤣

[@fay296k]

use 2 12v 50w halogen car light in series for high current charge

[@haatch999]

awesome way to get a cheap current limited supply add a voltage cut off board and that is the perfect charger for iffy batterys that your unsure on i use the 1800w boost converter set power supply to 48v set boost to 50.4 as wanted and current limited to what u wants gives an actual 8 amp power supply thats current adjustable with a low dollar mod ive pushed on of those 1800w dc to dc converters to 1600 continous they got hot but took 18ah worth of charging like a champ

[@lorriecarrel9962]

Don't apologise for having man's hands...

[@SayWhaaaaaaaaaaaaaaaaaaaaaaat]

WHAT LIGHTBULB?? led bulb?

[@christopherravizza4605]

I think a 30 buck imax charger is still a better choice, much more efficient, balanced charging, and all those extra features

[@AlexLTDLX]

It can't do 50 volt packs. That's the point of this.

[@hyahmuleart7144]

I would not watch that video nor give it a thumbs up.

[@davidresar8256]

Excellent idea!

[@adeptpeasant6161]

I'm here for the 🐈

[@AlexLTDLX]

Simon wouldn't leave when I was trying to take a photo for the thumbnail. So I figured, "Hey, I guess he's in it."

[@MichaelBLevi]

KITTY😸

[@dharmakissoon]

Lithium lead acid and capacitor

[@ryanmacewen511]

Cool video! Liked and subscribed!

[@SGRAHMD]

Your sound is like Tony Stark from Iron Man😅

[@kinanalhawat6753]

Clever, Cheap and Easy. OK But safe?😂

[@AlexLTDLX]

Sure it's safe - at least as safe as any lightbulb.

[@dennisford2000]

Safe as the loose nut behind the wheel

[@scottc78]

I'm waiting for April 1st when you to do a video like this that's totally fake :P. Fun stuff

[@AlexLTDLX]

You know I never thought of doing an April fool's video. You're giving me ideas... 🙂

[@johnnydanger57]

Tesla had nothing on you... ;-)

[@AlexLTDLX]

Lol - you're too kind.

[@williamzoom]

Very cool!

[@petermcgrath5215]

DIY... SO WHAT YOU'RE SAYING IS ...IF YOU WANT A BATTERY CHARGER GO AND BUY ONE.. DO IT YOURSELF.. have I gone crazy but the title said make a charger cheap and easy. I don't understand

[@SayWhaaaaaaaaaaaaaaaaaaaaaaat]

all psu'us have short circuit protection. dont buy chinese crap for 2$ if afraid of shortcuircuit. also you should use circuit dc braker for that too.

[@AlexLTDLX]

Many don't have short circuit protection. Most linear supplies certainly don't. Either way, that's not the point of the lightbulb - the lightbulb is a current limiter, not necessarily just short circuit protection. And it gives you a visual indicator of the state of charge. I thought it was a pretty clever use of a lightbulb, or in electronics repair parlance, "the dim bulb." In fact, in serious high-end industrial applications, there are specific, high precision light bulb current limiters that can be bought - if you're willing to pay the price.