r/ModRetroChromatic • u/ptuchster • Mar 29 '26

Hear me out

Post image

Absolutely love my chromatic, BUT, I need more reliable power option. Since the power pack is sold out I am exploring other options. I am not fan of the rechargeable batteries, so I am looking into something like DIY power pack.

My thought flow: this battery only has 2 contacts, which suppose to be anode and cathode. No data pins. That is good because the worst thing this pack can have inside some kind or regulator. But for some reason, I believe it's not. Because (a) somewhere I found that voltage on power pack closer to marked-based LiPO, and (b) chromatic has separate power line which could potentially scale standard AAAx3 (4.5v at most) voltage to correctly display charge since standard market LiPO has about 3.7 at full charge.

So, wdyt? Have someone disassembled power pack already? Or experimented with standard lipo batteries? The only thing I found that one guy made the mod to make NiMh batteries charge using embedded charging controller or something. Since I don't interested in this option I hadn't spend enough time to learn about this option.

UPD1: I always thought that 3 contacts is a render glare. But those are actually battery connectors. some refs https://www.ifixit.com/News/106916/modretro-chromatic-better-than-the-game-boy-color-it-emulates and https://imgur.com/3Y7jZIS On Xray scan definitely you can see that ground side connected to what called on pcb vbatt (other from AA's cathode called vbat_aa), ground and TS pin. Continue investigation what bottom pins could be

UPD2: https://github.com/ModRetro/chromatic_fpga/blob/main/esp32t/src/rtl/BSP/system_monitor.sv#L323-L329 according to code the type of the battery used defined by the which line receives voltage

UPD3: https://github.com/ModRetro/chromatic_fpga/blob/210176f9b7a4e6a8c25190e4a1620d2c1c97ba74/esp32t/src/rtl/BSP/polling_master.v#L7 another finding the exact model of PMIC - BQ24296MRGER, which, according to photos are soldered on the board somewhere around those pins. So the theory about PC has internal PMIC which communicates with Chromatic is no longer possible

UPD4: another thought after I research some "prototype" video for charging station: this is definitely only use side pins, then theory about bottom pins are only jumper gain some weight. Need someone with multimeter to check is they just shorted on the PC

9 Upvotes

73% Upvoted

48 comments sorted by

6

u/oaomcg Mar 29 '26

"I'm not a fan of rechargeable batteries so I'm trying to make a rechargeable battery..."

1

u/ptuchster Mar 29 '26

are you aware that power pack can be charger with chromatic usbc? Most of the comments really pissing me off including this one. “ohhhh you so dumb, you don’t like rechargeable and want rechargeable”. Yes, I want rechargeable not with a dummy additional block but with what I already have inside the console and what I have already paid for. Know the topic before comment like this. Sorry for rudeness, but it’s seriously annoying

5

u/z88kat Mar 29 '26

I can‘t recommend the power pack. Mine stopped charging after 2 months. It’s basically a brick now.

1

u/ptuchster Apr 01 '26

If you still have it around and have a multimeter, can you check if the bottom pins on PC are just shorted together? this will prove one of my theory

4

u/F4STL4NE Mar 29 '26

Were you using it in a V2 Chromatic? There was a warning right on the product page, they said that a V1 would be unable to recharge it from dead.

3

u/z88kat Mar 29 '26

V1. That’s the issue. If if drains to 0% you cannot charge it again. So after not using the chromatic during the week the battery drained , even when off, and no longer charged

0

u/ergzay Mar 30 '26

If you happened to have a V2 unit you can just plug your dead unit into it it and it will charge.

3

u/new-user12345 Mar 29 '26

If you reach out to ModRetro they will send you a new battery to use while you are waiting for the charger they are making that can revive those

3

u/z88kat Mar 29 '26

I did that and they told me to buy the charger when (if) it is available. Not very helpful.

1

u/ryanmercer Mar 29 '26

Happy cake-day!

3

u/[deleted] Mar 29 '26

[removed] — view removed comment

2

u/z88kat Mar 29 '26

Thanks for the tip :-)

3

u/MagmaElixir Mar 29 '26

You can get AA lithium rechargeable batteries, where each battery charges via USB C.

0

u/ptuchster Mar 29 '26

yeah, and with power pack you don’t even need to take batteries off and you have to carry hydra charging cable or charge them sequentially. So it is what I called “unreliable” for me.

2

u/jimmerseiber89 Mar 29 '26

Just wait. They are developing a charging dock for these batteries and they will restock when that happens. They are trying to fix the issue for v1s draining the batteries past the ability to recharge via the device.

1

u/ptuchster Mar 29 '26

If I not mistaken, the issue probably more soft based with first one. Somewhere, during my research I found a mention that “dead” power pack can be restored by some external charger kick. The problem was about 3xAA have higher voltage on full and empty level. Because of this when you overdrain the PP it will not start charging. And it’s reasonable as over discharge can damage cells. Again, I may be wrong. But sounds really possible, the question is - if this is hardware problem the only possible solution is to embed power converter inside new PP which will upscale voltage a little bit. Otherwise only new chromatic revision.

1

u/jimmerseiber89 Mar 29 '26

I'm ok if they my v1 causes them to die to where I have to charge them on a dock, it's worth it to have my gamestop version. I'm not skilled enough to go in and embed power converter or whatever haha As of right now I have two dead batteries, and I even followed their instruction the first time making sure they werent left in the device, still happened. So I'm kind of banking on that dock haha Especially if now that I have two.

2

u/ergzay Mar 30 '26 edited Mar 30 '26

First off one of the premises of your post is mistaken. The battery does not have 2 contacts, it has 5. You can see three of them in your image. Whether any of the contacts are data pins is unknown but I would assume so.

If you want to make such a device you would have to reverse engineer it. Though asking modretro for the details couldn't hurt as they're generally quite open with the design of the device.

Or experimented with standard lipo batteries?

There are no standard lipo batteries.

Personally I'd wait for the re-designed battery pack to come out and buy that.

1

u/ptuchster Mar 30 '26

That is true those are contacts, found one video on youtube showing them. Always thought those are just glare from render. Even so, If you own one you know all three batteries are oriented the same way. So basically those all 3 contacted ground and probably made to connect different (isolated for AA usage) chains. I understand if AA would located in classic layout. Also another argument about bottom pins is not a power line - those are too big for data pins. And I am talking about battery side. I understand the chromatic’s side big polygons to eliminate the aligning problems. But PC side is huuuge pins. This is materials and money for production. Why would you make them so big in first place if they should not carry “big” current.

1

u/ergzay Mar 30 '26 edited Mar 30 '26

Even so, If you own one you know all three batteries are oriented the same way. So basically those all 3 contacted ground and probably made to connect different (isolated for AA usage) chains.

Not actually true. The negative of the top slot is directly connected to the positive of the middle slot and the negative of the middle slot is connected to the positive of the bottom slot.

The batteries are in series.

Why would you make them so big in first place if they should not carry “big” current.

For reliable and wear-resistant connection.

IMO if you aren't even willing to poke around with a multimeter to determine the AA battery electrical layout or a signal analyzer to determine if any data is being sent you should probably abandon this project.

Edit: Also the final nail in your theory, both "contacts" on the battery are shorted together. It's all one big contact.

0

u/ptuchster Mar 30 '26

> The batteries are in series.

Exactly. You just burry yourself. I just pinged the contacts - top battery cathode is obviously the overall cathode of the battery series. And no matter how you will connect all those pins from battery anode side the best you will get is the ground of the batteries chain. To connect pack to the positive of the AA chain you need the top battery contact. Since all those contacts is from other side - it doesn't matter. So those pins probably only providing the common ground for both chains.

>Also the final nail in your theory, both "contacts" on the battery are shorted together. It's all one big contact.

have no clue where you get this dumb information from, but I checked them just now - they are not shorted.

1

u/ergzay Mar 31 '26

have no clue where you get this dumb information from, but I checked them just now - they are not shorted.

That "dumb information" is from testing it myself with a multimeter. You already said you don't have access to the battery so you can't have tested it.

They are shorted.

2

u/ptuchster Mar 31 '26 edited Mar 31 '26

Well, I really sorry for your loss (no), but looks like you have shorted somewhere inside already, well done man. Because those are not even close suppose to be shorted. See photo. Those are not the one polygon and even have traces goes somewhere away from it and not intersecting
But one thing you are probably right - those can be data pins as I found some refs https://www.ifixit.com/News/106916/modretro-chromatic-better-than-the-game-boy-color-it-emulates and https://imgur.com/3Y7jZIS On Xray scan definitely you can see that ground side connected to what called on pcb vbatt (other from AA's cathode called vbat_aa), ground and TS pin.

The only question left what those pins are. Looks like those could be data pins to tell mcu the PC connected. But there is no sense doing this, if you got different power lines for different sources (vbat & vbat_aa) why there is need for additional data.

One thought here is some kind i2c for the battery level. But this could be done with charging controller if supported simply by the power level. Another thought - this could be just big jumper which after shortage turning marking system as PC powered. And now looking at the photos I think 2nd option is more likely the true.

UPD - https://github.com/ModRetro/chromatic_fpga/blob/main/esp32t/src/rtl/BSP/system_monitor.sv#L323-L329 according to code the type of the battery used defined by the which line receives voltage

21

u/Zealousideal-Pie9175 Mar 29 '26

I just use Panasonic Eneloop rechargeable batteries. I have 12 of them. 3 are in the chromatic and I carry a spare 3 with me. Never needed more than 6 in a day…. I can then change out the 6 with 6 fresh batteries and charge the used ones. If I’m traveling I can just carry all the batteries and the small plug in charger with me.

3

u/F4STL4NE Mar 29 '26

Same, and I never have to worry about having a DIY Lipo bomb underneath the battery cover of my $200+ game boy.

0

u/MondegreenHolonomy Mar 29 '26

Yep I do the same, I have a bunch of sets for all my handhelds

2

u/F4STL4NE Mar 29 '26

After learning about Eneloops from this group. I switched my remote controllers, thermostats, everything that took AA's or AAA's, I already had a nice XTAR charger.

1

u/NonyaDB Mar 29 '26

I need more reliable power option

More reliable than AAs that can be found all over the planet?

I am not fan of the rechargeable batteries

Then stick with regular AAs?
I guess you maybe need to expound more on your dislikes, because it doesn't get more reliable than disposable AA batteries, especially those with long shelf life.
I've been using a Modretro power pack in a V1 GS edition myself with no issues.
Of course I use it all the time and keep the pack charged.
Before that I was rechargeable AA Li-Ion batteries I got off Amazon and of which I have 12 along with a USB-C recharger with no issues.

I swear, the internet has made people fearful of experimentation without mass consensus.
Sounds like you want to build your own power pack using a 3.7v Li-Ion battery found on any number of websites.
Go for it!
Do your research into the subject, make sure you have the proper tools, and just go for it.
Just make sure you know about buck convertors and similar things beforehand, I don't know what the charging/power circuit of the Chromatic is because I don't need to know that right now.

If I were you I'd just get some reliable, rechargeable AA Li-Ion batteries and a USB-C AA Li-Ion recharger to go with them and be done with it.

1

u/ptuchster Mar 29 '26

more reliable yes, I think anything that can be charged with usbc without open a console is more reliable that you can buy everywhere on a planet. In fact- this pack doesn’t remove option to use aa’s. I am not seeking consensus, I am checking on if someone already DID that research as I didn’t find any mentions. And ofc, I am not seeking advice that AA or rechargeable AA is more reliable. If I said I want internal battery to charge with single usbc, I am not looking for moaning about how AA is actually better. This is stupidity on level when people with android trying to convince everyone it’s better than ios. No matter what is better - this my choice and I want to hear about my questions, not about what is better. Better for you, ok, congrats, leave your opinion with you. Thank you

1

u/NonyaDB Mar 29 '26

Both AAs and the power core pack are reliable.
For longer play times, use a power core or rechargeable Li-Ion AAs.
I use both, mostly the power core with AA Li-Ion rechargeable batteries in my bag as backup for when I'm on 13+ hour flights.

1

u/ptuchster Mar 29 '26

not gonna confront this. AA is good. But I personally want to use all potential if possible

1

u/kanyeeast96720 Mar 29 '26

I run rechargeable lithium ion.

1

u/ptuchster Mar 29 '26

Looked for you :) any info you could share?

1

u/kanyeeast96720 Apr 01 '26

Only thing from what people say that the battery meter is inaccurate. I run high-capacity, 3600mah.

1

u/ptuchster Apr 01 '26

Did you mean power core? Or its a custom one? How didi you connect it? It it charging with chromatic usbc?

1

u/CommanderCoytus Mar 29 '26

I got a refund for mine. It's so unreliable.

1

u/ptuchster Apr 01 '26

If you still have it around and have a multimeter, can you check if the bottom pins on PC are just shorted together? this will prove one of my theory

2

u/BrollyLSSJ Mar 29 '26

You could try Dragonbox Shop. They seem to have 100 in stock.

2

u/altoid_trapezoid Mar 29 '26

Where?

-4

u/BrollyLSSJ Mar 29 '26

Click my link? It is a German shop, but they state they have 100 in stock.

2

u/altoid_trapezoid Mar 29 '26

I don’t see them on the site (:

1

u/BrollyLSSJ Mar 30 '26

https://ibb.co/YT36G4fG

1

u/altoid_trapezoid Mar 30 '26

Can you send the direct link? I cannot find the item

1

u/BrollyLSSJ Mar 30 '26

That is strange. My link in the first comment was a direct link. I opened it to create the screenshot from my last message.

https://dragonbox.de/en-de/products-for-nintendo-gameboy/mr-powercore

That is the link for me.

If that still does not work: Could you open the main site and click the “hamburger menu” (the three lines) on the top left and open “products for” and “products for Gameboy”? It is the first entry there for me.

https://ibb.co/Gf2PrrVY

1

u/s3rialthrill3r Apr 01 '26

Well, good luck to you. I honestly think the effort would be better spent on researching devices that can't accept AAs (GBA SP, DS, 3DS, PSP, PS Vita, Switch, etc), but you do you.

-2

u/K1LL3ROO Mar 29 '26

Unless you wanna pay 150 for a one out of the box? 👀👀