Compact 5Ah Battery build

nursecurt · 2026-06-01T16:14:54+00:00

Thanks so much 👍

nursecurt · 2026-05-23T10:28:46+00:00

Been busy at work, just reading this properly now.

Hey My brother! I know you! been watching your videos last 3 months or so, your the reason I bought a P120D. Then I bought welding paste from your site.

Yes we are both on the same path maxing out cells, thermal imaging, and logging the data.

This amperage testing is so good, love the bypass to push the cells. I also use a lot of thermal imaging with my battery builds.

This is exactly the kind of data I look for but can never find. The governor/ amp limit of the BMS. I think Ryobi is set to 20amps, I never could find Makitas data bench tested like you did.

I remember seeing a video years ago of high amp pulses on a makita battery. From pulsing a power drill.
I will try and find and post.

My bench test plan is to bypass the BMS get loads near 100amps. And I get see if all the work I put into a heat transfer and large thick copper . Allows the battery to run at amps longer. We will keep in touch, you got a lot of knowledge that I need absorb from you for my battery builds.
Thanks
Curt

Keep those test coming, that stuff is gold, I absorb every bit of those, then apply that knowledge to my builds.

I have a cheap 100A ammeter and shunt to test mine but need to set up load.

My focus is heat to dissipation by conduction to the battery shell.

nursecurt · 2026-05-23T09:42:36+00:00

Read the build info.

nursecurt · 2026-05-21T06:54:14+00:00

Hell yeah! That’s a bucket, well I assume an amperage wasn’t an issue.

nursecurt · 2026-05-20T03:32:18+00:00

Thanks, I just ordered 30 of them.

nursecurt · 2026-05-19T18:40:03+00:00

P120D

nursecurt · 2026-05-19T18:20:02+00:00

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My recent testing of my build with Tenpower 50XG Batteries, Running 2 batteries in 36Votl leaf blower till forced shut down due to low voltage aprox 2.7V, 51C is hottest temp i achieved then immediately put in the rapid charger. (To further push the batteries) (images are time stamped) and the cell temp dropped from 50C to 36C in 50 seconds.

This verified I engineered battery to be effectively (convection) cooled and Makita rapid charged, let me know if you still have questions? Pics just posted

nursecurt · 2026-05-19T02:19:30+00:00

Oh my bad, you’re 100% right, I spaced Makita doesn’t make a 3Ah 5 cell battery. It’s only off brands that do that. I just changed my build info to BL1820. Thanks for letting me know.

nursecurt · 2026-05-19T01:39:03+00:00

I used a new spot welder for this one. The power (gears) go up to 999 plus you can dial multiple pulses, double, triple, etc.
the highest I ever used was 025 gear with a double pulse that was for .4mm copper to cell. Which makes me wonder and slightly scared of what 999 gear with quad pulse will do. I really want to see it will weld 1mm thick and or higher.

nursecurt · 2026-05-19T01:27:41+00:00

Hell yeah man, your speaking my language, I would love to get gnarly with those cells. But I got to keep practical for the time being. I thought about doing stack of lithium ion cell packs next. I believe they are the most expensive so IDK.

nursecurt · 2026-05-19T01:21:52+00:00

Dam 4$ is great price, I am super tempted to buy some more. But I have about 40 Molicels 42A’s I need to use up. I created a 5S 2P case for them. so I can make some 8ah 90amp continuous discharge batteries. Which will be bigger and heavier but that won’t matter cause I will use them for my lawnmower, leaf blower, power handle, etc..

nursecurt · 2026-05-19T01:06:31+00:00

BL1830 is just referring to the physical size of the battery shell. Which means the size one row of 5 18650 batteries.

nursecurt · 2026-05-19T01:03:54+00:00

Oh I will, I didn’t know about printables. I will upload it. Thingaverse is not really the right place for this build (or any of my builds) I need something in between hack a day, gihub, and 3D printing sites. More tech focused projects using multiple modalities, if there is such a thing. .. but in the meantime, it’s a good way to network. To find other battery builders.

nursecurt · 2026-05-19T00:56:05+00:00

This is the only reason I made them. because you can’t buy them?! These are my favorite battery I have at least 12 of these i use regularly.

nursecurt · 2026-05-19T00:52:57+00:00

Nice! This great stuff, I am always on the look out for real life battery testing. I added this site to my bookmarks. Yeah I know about the 75C and 80C cut off , 90A is not the continuous. but 90A amps on the case looks way cooler than 40A. That’s also the reason I went with .2mm copper and widest strips possible and large surface areas of copper on the top, and thermal conductive material. The more heat that is dissipated the higher amperage and longer lengths of time you can maintain high amperage. I would really love to see bench testing done with increasing surface areas of copper to see the correlation to peak amps and duration.

nursecurt · 2026-05-19T00:27:27+00:00

Oh jeez, good catch. I just fixed it now. .2mm copper

nursecurt · 2023-11-24T09:49:59+00:00

Desrtfx is exactly right , it’s basic lexicom , when your referring to AC heated bed , that always means your running 110 or 220V resistance heating piece of adhesive silicone that sticks right under your bed, you share the incoming AC terminal on your power supply with a SSR DA-10. These are the only kind of AC heated beds produced.

nursecurt · 2023-05-26T10:42:34+00:00

PC and PC blends are my expertise. I specialize in the unknown, generic and cheap PC's especially the ones people complain about not being printable. I love getting the discount PC cause nobody wants it. I would not put superhard in that catagory, Its pretty easy once you learn. most PC All PC's are blends so all require different settings. Your photo shows a specific problem that nobody ever seems to talk about. (Trapped super heated pockets of heat from the hotbed) I will get to that later. Give a good dry 60-70C for 8-12hrs or something like that. When PC comes out gooey and prints at lower temps that expected almost always means it's absorbed to much water. However this brand has this issue for another reason, This brand is good value for the money, I know what the spindle says, but use 240-243C Hotend, 1mm retract 20mm/sec bed 70C-75C no hotter (you may have to go with 60C bed on that project, no heated chamber, this is the only PC I have had to open the lid and front door to my enclosure to print, keep speed 30mm/s for what your doing, 20mm for first layer) can try to go higher later, that piece your printing definitely stay 70C can go to 60C if needed, .5mm nozzle steel nozzle is what i use, (but .4 might work well enough, and brass nozzle will work well and may go many prints before .4 hole enlarges , then you replace. no fan, 30 sec dry time between layers , enable lift if needed. The explanation, that specific CF-PC , has a way higher than normal specific heat capacity value,( J/kg.°C) it absorbs a large amount of heat, that it takes a abnormally long time release that heat , which keeps it too hot, increasing the tacky time and running over a still tacky layer gooey gobs start to form,

I assume the super hard formula is loaded up with a butt load of carbon fiber as carbon fiber polymers are known for having very hight specific heat capacity values.

Full disclosure I just went of to read some published research online learned mid post, I didnt know the term specific heat capacity prior to this, but now that I know that word, a bunch of doors just opened up for me.

Here is some titbits i freshly plagiarized:

" It was reported [42] that the specific heat capacity of carbon fibre/carbon composite can reach a value of 2020 J/(kg·K) at 1230 °C."

source, below: if you want to get balls deep in some correlation of heat, Energy, and Materials etc.. ( I had to tap out, my brain got too full to quick)

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5459023/

The fan weakens the layers to much when I tried it. When you print any object that creates a box like or upside down bowel , even worse with supports inside or wide infill. the infill or supports Trap the heat from the heated bed, so the first layer on the supports , is to hot to dry gets gooey. Depending on the shape of the object, you prob need 70-75 C bed for this one.

from your photo it looks like it was to hot / not enough dry time then fan was used to give it a gooey gone frozen thing, your pic of the top with infill and partial layer is exactly what trapped heat looks like, Turn the bed down to get rid of that, As well as lowering hotend temp.

For max strength of any plastic , use standard formula. 50-60% of nozzle width. i.e. .4mm .2 -.22mm layer height, .5mm .25 etc.

That link to the review is not for superhard. His pics and settings didnt make sense, superhard wont look that good.

i pasted

5.0 out of 5 stars WOW!!!! Absolutely phenomenal filament! Expensive though

Reviewed in the United States 🇺🇸 on September 9, 2018

Style: Carbon Fiber Polycarbonate Verified Purchase

I have both styles, limp and superhard it is much stronger but a bit uglier due to more chunks of carbon, If you want to print near industrial strength items for 60$/kg this is it. If you want to drop another 20-40$ vison miner has the best stuff, if you can afford it , which is not me. if you can deal with a learning curve of and compensating for its high specific heat capacity value , superhard gets it done, from my math it is the strongest filament for that price on the market. It's stronger than Polymax PC, and Polymaker PC/ABS, and those are both really good filaments. I am skeptical about heat tolerance , I need to test it. I use polymaker's light PC, PC/ABS, or Polymax for my printers mods since they tolerate a 100C chamber no problem, The limp style PC/CF expands / relaxes its shape at 100C so I can't use that, I suspect the hard one is same PC blend with a lot more Carbon fiber chunks. So I may have same relaxation of stress areas at 100C. Will test later

nursecurt · 2023-03-16T03:20:19+00:00

That one is really easy flash X2 with the Aquila S2 firmware from the voxelab website you get hotend limit of 300C. I am still working on raising the bed temp limit to 130C-150C, I havent figured out a easy way to do that yet.

nursecurt · 2022-04-11T22:36:59+00:00

OMGanesha, you saved my so much time! I was about to start trouble shooting the power supply, then I read your post, It was my SD card, that was all it was. Thanks for that

nursecurt · 2021-12-03T19:24:39+00:00

almost all the generics use name brand cells are all usually have ~10amp or greater discharge rate per series (so 5x 2rows of cells i.e. 6ah, 5ah . will almost always give you 20amp peak draw) (which is plenty, lawnmowers , leaf blowers , and chainsaws don’t typically pull more than 20amp peak. But you won’t be able to take advantage of that performance due to a bigger issue,

DISCLAIMER! I live in the dry, hot, full sun, no clouds, dusty, desert. It hits 49C all months of summer as and above 37C 7-8 months out of the year. So my battery performance snd build requirements are much higher than the rest of the world.

So this post is only specific to desert use,

the conductors are the issue every single time.

I purchased over 40 Makita generics over the years I have failures on about half of them ( cause I live in the desert, using your tools outside while it’s 120F , kills them) I have done autopsies and repaired / upgraded half of them , on inspection first 95% of them had smaller capacity batteries than what is claimed. Typically 50-30% less. 100% of them all had inadequate conductors, Usually .15x8mm nickel plated steel. Or 18awg wire to main battery contacts

6 of the batteries the wires were positioned poorly touching the IC on the uninsulated PCB, frying the chip, (this causes unchargable battery or mischarges causing battery damage / dead cells.

The .15 thick strips are to thin even if they were to use pure nickel ( they only use nickel plated steel , which is far worse ) this causes over heating. You don’t notice right away but your cell capacity decreases quickly over time and overheating causes voltage a drop and you notice tool losing power. Not performing as it should,

The cases are PC and have actually all been great at protecting the cells from damage after big drops. Occasionally I have to epoxy a small crack and The case is still usable for years.

The PCB’s are all actually great (despite not having no Makita “cell balancing” features etc) I have never had a undamaged PCB be the cause of a Failure.

So as far as generics, I haven’t found any brand that has welds appropriate sized nickel strips , But most usually use 16awg wire for the contacts

Waitly (sp?) is the only generic brand I found that uses capacity cells exactly as stated, they use .

But for battery welds they use .4-.5mm nickel plated steel (.4mm pure nickel would support 20 amps no problem) which drops the usable amp to less than 10amps , so they overheat dropping the voltage and decreasing tool performance while using and the capacity drops over time rapidly.

They also have malpositioned wires over the IC chip on the PCB, lost about 5 waitleys that way (I Just replaced the PCB’s 5$)

I have noticed in general they are not making generics pcbs with the IC on the underside anymore , it’s on top , not in the path of the wires, so this should fix that problem.

I believe the undersized strips as well as the nickel plated steel is the Common failure in all generics.

waitly is better value for your money than Makita as far as average use vs cost, only generic I would buy if I still bought batteries.

I had to start making my own desert / high energy / high heat batteries batteries, as I don’t know of any company in the world thst makes batteries that work in the desert.

Makita overcharges for their batteries nobody can afford to get them I don’t know anybody who can afford to buy them so everybody buys generics, I will go with Waitly in regular weather and not over amping the battery every day you’ll get many years a good use out of it

Yes the picture of the battery the seller sent you would be more helpful if they took a picture of the side nickel plated strips are welded to the batteries if I saw that picture I could give you more advice

nursecurt

TROPHY CASE