Started my first portable (SNESp Retro Duo) - worklog

zzattack · Post by **zzattack** » Thu Sep 25, 2008 12:59 pm

Life of Brian wrote:I wonder what the problem is. I'm very interested in the RGB mod you discussed. If it works, then that makes Retro Duo an all around winner in my opinion - fairly similar cost to SNES mini, RGB, lower power consumption, and smaller size.

Yeah I agree. I'll post when/if I get the RGB mod working but without a screen it's gonna be hard. This thing should arrive real soon though, it was shipped a couple of weeks ago. I 'debugged' the problem. Basically I think the protection board wasnt working properly. The output voltage was just fine but as soon as there was any drain it would shut the battery supply, as if the batteries were low and it was protecting them from undercharging. I replaced the protection board and the same problem persisted. After not knowing what to do I figured, hell I'll try a 3rd protection board. Unexpectedly, everything worked fine from with that one.

Some more good news: my new plug looks pretty nice. Fairly useless, but still nice.

<img src="http://zzattack.org/photo/thumb_third day/IMG_0035.JPG">
<img src="http://zzattack.org/photo/thumb_third day/IMG_0036.JPG">

Some bad news too: battery fire. Last night I drained the batteries completely. They were attached to the protection board which protects them against undercharge, so I figured it'd be fine. I measured the batteries today before attaching the new power plug. One battery was 2,4V and the other was 2,9V, I wondered where the 0,5V difference comes from, but I didn't worry as I expected this would be about the lowest acceptable voltage allowed. So after my plug was done, I connected the first batteries wires' back to the protection board. Went fine.
Then I started to connect the other battery. First wire, nothing bad, second wire, while the solder is melting the other (already connected) battery catches fire!! :S My only explanation can be that the battery is undercharged. The batteries weren't hot because of soldering at all either. I blew the fire out instantly, I think it burned at most 1 second, definitely less than 2. The clip shrunk a lot, and the bottom now looks like this:
<img src="http://zzattack.org/photo/thumb_third day/IMG_0037.JPG">I suppose it's a very good thing I was this fast, as when the clip would have totally melted it would have probably blown the whole battery.
That sucks. I ordered 4 batteries though (yes, 2 useless now, 1 clip broken and 1 on fire), so I can just continue I guess.

But can I complain to batteryspace about this? I think the battery was protected so it shouldn't have been able to fire. Also this was the 3rd protection board I used.

Rekarp · Post by **Rekarp** » Thu Sep 25, 2008 4:44 pm

batteryspace protects there but about stuff like this when you click that "I understand all the risks with lithium batteries". Did you wire the protection circuits correctly? Sounds like user error.

What batteries where you using and which protection circuit? How did you wire them and the plug?

zzattack · Post by **zzattack** » Fri Sep 26, 2008 2:47 am

I've bought them from these links
'

lovablechevy wrote:
nuky nuclear wrote:thanks for the help. these arent the ones for the ipods are they?
no. they are these batteries, this pcb, and this charger.

I've wired them according to the schema that was provided with the protection circuit. Later I found lovablechevy's diagram, my wiring was exactly the same as hers.

lovablechevy · Post by **lovablechevy** » Fri Sep 26, 2008 7:04 am

did this happen when simply soldering the wires on? like, it wasn't hooked up to the charger yet? if so, i had a similar experience, but no actual fire was involved.

but, if you were using my completed diagram...

i'm actually still not completely certain why this happened to my wires. but, when i go the courage to try again, all went well.

you said they were already hooked up to the pcb? did you wire up all grounds first and then the positive...? i don't know if it really matters or not, but now i always connect grounds up first and then the positives.

i sure hope that you can still use that battery! but at least you have 2 others to work with.

Rekarp · Post by **Rekarp** » Fri Sep 26, 2008 8:57 am

how did you discharge the batteries in the first place?

What happened was that you probably didn't FULLY charge the batteries like is says in the instructions before discharging them. The reason one blew was because the .5V difference probably flooded the lower voltage battery with allot of amps causing it to go poof. V/R=I Since it was a wire R is very small like (.0000001 ohms basically zero) so you would have a theoretical infinite amps going through into your discharged batteries. This is why battery manufactures state to never mix batteries of different charges (old mixed with new) or different types. This is why you get battery acid all over your calculator...

zzattack · Post by **zzattack** » Fri Sep 26, 2008 9:26 am

lovablechevy wrote:did this happen when simply soldering the wires on? like, it wasn't hooked up to the charger yet?

The charger wasn't hooked up. The ends of the wires I was putting on the batteries were already soldered to the protection board. The first battery was fully connected, for about 1 minute. I was busy soldering the wires of to the other battery when the connected one caught fire.

you said they were already hooked up to the pcb? did you wire up all grounds first and then the positive...? i don't know if it really matters or not, but now i always connect grounds up first and then the positives.

I was working through the wires from left to right with the clips facing me, so I from the first battery I connected the ground first, then its positive, then the next ground.

Rekarp wrote:how did you discharge the batteries in the first place?

One day I connected the batteries to the protection board and fully charged them for at least 5 hours. Both batteries indicated about 4,2V. I discharged them at night the day I put the new plug on. Before I put it on I disconnected the batteries, when I was done with the plug I soldered the wires back to the batteries. Before I was done with the 2nd battery, the 1st one caught fire. It was only visible on the clip and the battery didn't feel hot at all. Do you think it's still usable or wouldn't you risk it?
Thanks for all the replies.

lovablechevy · Post by **lovablechevy** » Fri Sep 26, 2008 9:55 am

zzattack wrote:One day I connected the batteries to the protection board and fully charged them for at least 5 hours. Both batteries indicated about 4,2V. I discharged them at night the day I put the new plug on. Before I put it on I disconnected the batteries, when I was done with the plug I soldered the wires back to the batteries. Before I was done with the 2nd battery, the 1st one caught fire. It was only visible on the clip and the battery didn't feel hot at all. Do you think it's still usable or wouldn't you risk it?
Thanks for all the replies.

why did you disconnect the batteries when hooking it up to the plug...?

i personally think that the battery is fine. try wiring all grounds first and then positives. just be ready to be quick in case there is something wrong with the battery. but if it didn't even get hot, then i think it should be fine.

zzattack · Post by **zzattack** » Fri Sep 26, 2008 9:58 am

lovablechevy wrote:
zzattack wrote:One day I connected the batteries to the protection board and fully charged them for at least 5 hours. Both batteries indicated about 4,2V. I discharged them at night the day I put the new plug on. Before I put it on I disconnected the batteries, when I was done with the plug I soldered the wires back to the batteries. Before I was done with the 2nd battery, the 1st one caught fire. It was only visible on the clip and the battery didn't feel hot at all. Do you think it's still usable or wouldn't you risk it?
Thanks for all the replies.
why did you disconnect the batteries when hooking it up to the plug...?

i personally think that the battery is fine. try wiring all grounds first and then positives. just be ready to be quick in case there is something wrong with the battery. but if it didn't even get hot, then i think it should be fine.

Gave me a little more space, and I shorted the plugs quite a couple of times which would short the "output" on the protection board as well so I figured it wouldn't be a bad idea. I'll await rekarps response before hooking the battery up again, he seems to know a lot about this, but thanks for your reply nevertheless.

lovablechevy · Post by **lovablechevy** » Fri Sep 26, 2008 10:02 am

zzattack wrote:Gave me a little more space, and I shorted the plugs quite a couple of times which would short the "output" on the protection board as well so I figured it wouldn't be a bad idea. I'll await rekarps response before hooking the battery up again, he seems to know a lot about this, but thanks for your reply nevertheless.

umm... thanks...? i only use the batteries all the time...

and you should have never disconnected the batteries from the pcb.

oh yeah! and in reference to this:

zzattack wrote:The output voltage was just fine but as soon as there was any drain it would shut the battery supply, as if the batteries were low and it was protecting them from undercharging.

also had a similar experience. the next few posts give the answer of what was wrong.

Rekarp · Post by **Rekarp** » Fri Sep 26, 2008 10:37 am

You said you discharged the batteries before doing this? How did you discharge them? Resistor, shorting terminals?, ect?

You said it took you a minute to hook up the other battery? You know the instructions say to never apply a soldering iron for longer then 3 seconds?

lovablechevy · Post by **lovablechevy** » Fri Sep 26, 2008 10:41 am

i was just thinkin about it... why did you even fully discharge the batteries right after fully charging them...?

zzattack · Post by **zzattack** » Sun Sep 28, 2008 7:50 am

lovablechevy wrote:i was just thinkin about it... why did you even fully discharge the batteries right after fully charging them...?

It wasn't right after fully loading them I think, but I was just trying to see how long it would power the console. Not that it'd be a good indication as there was no screen attached.

grahf · Post by **grahf** » Wed Oct 01, 2008 4:39 am

What part of the RGB mod is giving you trouble? The Retro Duo uses a CXA1645, right? You can share the sync signal with the encoder. ie: pull it off of the input pin on the '1645. Also, the capacitors your using should be 220Âµ. And if that Zenith screen is the same as a PSOne lcd (which I think it is), you won't even need them since it will handle filtering/leveling the signal itself. Just run them direct to the screen. You may need to put a cap on the sync line, if it's unstable. Depends on the wires/etc.
HTH.

-Ben

zzattack · Post by **zzattack** » Wed Oct 01, 2008 8:11 am

grahf wrote:What part of the RGB mod is giving you trouble? The Retro Duo uses a CXA1645, right? You can share the sync signal with the encoder. ie: pull it off of the input pin on the '1645. Also, the capacitors your using should be 220Âµ. And if that Zenith screen is the same as a PSOne lcd (which I think it is), you won't even need them since it will handle filtering/leveling the signal itself. Just run them direct to the screen. You may need to put a cap on the sync line, if it's unstable. Depends on the wires/etc.
HTH.

-Ben

I really have no clue yet, it's been almost a month ago that my screen was shipped and I still haven't received it. Trying the mod with a SCART cable seemed an option to me but I didn't have a spare plug lying around for it, and currently I have exams so I haven't really tested it. I think the retro duo has a KA2198BD chip by the way, though you're not the first one to suggest a 220ÂµF cap so I'll keep that in mind if it won't work.

Major bummer yesterday: got a sort of unexpected UPS bill. My "free sample" from polycase, a 700 grams box stuffed with their advertisements appearently cost E89,31 ($125) for UPS to ship to me. I don't think I'll pay them though, it was sent through UPS Expedited, one day late, so that should AT MOST be $20. I'm never shipping through UPS again.

grahf · Post by **grahf** » Wed Oct 01, 2008 9:39 am

Sorry to hear about the shipping fiasco!

The KA2198BD (Samsung) is just a CXA1645 (Sony) clone. It has the same pinout and is designed to be a drop in replacement. Upon inspecting the data sheet, it <b>does</b> appear that Samsung recommends the 470 caps as opposed to the original.

The RGB signals are already clamped or amped (normalized) by the IC, but the final cap+resistor is needed to further tweak/filter the signal so it can be used by a monitor or TV. The PSOne variety of LCDs "filters" the signal itself, so you can most likely save space by ommiting the cap+resister. With CXA1645s, I found you can do without them.