SDS100/SDS200: SDS100 Battery Hack for Record/Play

[pghDave]

I know there's a lot of discussion in other threads on the SDS-100 battery but I didn't think any of it focused on a possible workaround for the fact that the radio will not record without the battery pack.

Has anyone looked into what would need to be provided from a battery pack substitute to bypass/fool the feature that protects the SD card. I don't want to power the radio from the hack-pack just trick it into thinking it has a battery while on USB power.

More specifically I'm wondering about a simple, small, non recharging battery that puts enough juice into the radio to fool it into thinking it has a regular battery pack installed. I suppose it'd need protection against charging (although I guess if you always remembered to use the non charging USB connector this could be skipped).

My one battery pack did the swell thing while traveling last month and I wanted to at least keep the case/connector pieces but being on the road I didn't feel that I could safely fool with the swollen battery. Perhaps when the second one goes I'll cannibalize it for a hack attempt.

Has anyone tried something like this or pondered it enough to rule it out.

Thanks in advance.

 

[Ubbe]

I was going to look into it but I just cut away the battery cell that had swollen. It was only one cell of the three that had swelled in my battery and the two others haven't expanded one bit. All three cells are connected in parallel so it doesn't matter if you have just one cell left. I had to use some foam padding inside the battery to make it connect to the scanners three charging pins.

/Ubbe

 

[pro106import]

I was going to look into it but I just cut away the battery cell that had swollen. It was only one cell of the three that had swelled in my battery and the two others haven't expanded one bit. All three cells are connected in parallel so it doesn't matter if you have just one cell left. I had to use some foam padding inside the battery to make it connect to the scanners three charging pins.

/Ubbe

That's a good idea Ubbe. I'm going to keep checking eBay for someone selling their swollen battery cheap. ( hint, hint ) Hope they pack it in a metal can!

 

[nessnet]

That's a good idea Ubbe. I'm going to keep checking eBay for someone selling their swollen battery cheap. ( hint, hint ) Hope they pack it in a metal can!

Gawd... I hope not.
No one should be shipping a swollen LiIon battery anywhere!!

 

[pghDave]

Starting simple -- Does anyone have the pin-outs for that 3 contact connector?

 

[Ubbe]

The top pin nearest the antenn are negative and the bottom one are positive. The middle pin seems to be a 10K resistor, or probably a termistor for temp check, connected to ground at its other end.

It comes nothing out from the pins on the scanner. So it will need a battery with some voltage to start detect and charge. It probably don't need anything from the temp sense as it most likely goes down in resistance when it gets hot and just turn off charging. I believe that there's a temp sensor inside the scanner so that if the temp goes too high it switches off the whole scanner.

/Ubbe

 

[Omega-TI]

How about a 3D printed battery replacement? One could attach metal contacts to the phoney battery and also print up a replacement door for the cord to run out. Plugging into a UPS would give one the requisite power proofing.

 

[pghDave]

Yeah, I was thinking along those lines. I'd probably keep it a little simpler and have the 3d shell the same size as the extended battery pack and clip and avoid the stresses put on those parts.

The fake battery only needs to put 3.7v on those contacts in order to vote "present", if I understand correctly. In my use case I'd still power the scanner via the USB cable but with juice on the internal connectors the record functions should be enabled, right? Don't need much juice from the fake battery since it'd not really be doing anything but I suppose the scanner may have some minimums it expects to see from the battery before it shuts off record capability? I guess we need to know/learn those trigger points.

I guess it'd be wise to pop a diode inline to avold any charging juice from getting to the fake battery.

In my simple mind I see hot melt glue, a yet-to-be determined alkaline battery, a diode fitted into the existing compartment and provide the necessary juice to fool the scanner. What am I over simplifying??

 

[Omega-TI]

Upon further reflection, I'm thinking the fake battery and door could be one unit as for the guts, maybe someone else will jump in with some ideas.

 

[Omega-TI]

@a417 Since you don't like the idea, at least tell us why.

 

[a417]

Yeah, I was thinking along those lines<snip>
The fake battery only needs to put 3.7v on those contacts in order to vote "present", if I understand correctly.
<snip>
I guess it'd be wise to pop a diode inline to avold any charging juice from getting to the fake battery.

In my simple mind I see hot melt glue, a yet-to-be determined alkaline battery, a diode fitted into the existing compartment and provide the necessary juice to fool the scanner. What am I over simplifying??

Would it make more sense to present the 'battery full' voltage to the device? If it sees 3.7v it might try to charge, if it sees a fully charged battery voltage on it - wouldn't that say "hey, don't charge!". Something current limited, of course?

 

[Omega-TI]

Or one could toggle off the charge while using.

 

[a417]

Or one could toggle off the charge while using.

This in no way helps the OP's original issue which was record without a battery in the device.

 

[Omega-TI]

The point was a battery replacement, which a 3D printed dummy would accomplish. Turning off the internal charge function would get past the charge issue. It seems like a viable solution to me.

 

[a417]

The point was a battery replacement, which a 3D printed dummy would accomplish.

No, it was not. I'll quote below what the OP's original plan was.

I don't want to power the radio from the hack-pack just trick it into thinking it has a battery while on USB power.

See? You're straying into straw man territory.

Turning off the internal charge function would get past the charge issue. It seems like a viable solution to me.

It seems like a viable solution to your situation, not to the problem that the OP is not trying to actively solve.

 

[KevinC]

Will you two please get over each other!

 

[a417]

I'm multitasking! I'm engaging the OP with relevant discussion towards his idea and solution, and dealing with someone who demands "maybe someone else will jump in with some ideas." as long as it's not me. I'm actually trying to keep the thread alive, not dive off into the weeds.

 

[pghDave]

So being the OP, let me restate my goal:

Operate the SDS-100 on USB power WITHOUT the standard SDS-100 battery pack installed AND retain record functionality. This is driven by a somewhat unnecessary (although understandable) function in the SDS-100 firmware that disables recording to the SD card if there's no charged battery in the compartment.

The theory was put XX volts on the pins in the battery compartment and the safety feature in the firmware will be fooled, My use case is happy to require USB power to actually operate the radio so the capacity of the fake battery can be minimal.

A couple of gotchas came immediately to my (and other minds) including:

1) the fake battery could be charged errantly if the wrong USB port on the scanner was connected. A manageable risk but also one that could likely be prevented with a simple diode or attention to detail when connecting the USB power.
2) Corruption of the SD card if the scanner is writing to it and loses USB power and the fake battery can't actually power the radio. I can live with this. Back up SD card can be standing by.

My reasoning for wanting this is that I operate my scanner almost always where USB power can be provided. I only want to have to rely on the prone to swelling (my assertion, my history) battery packs for true portable operation. BUT I don't want to give up record/playback capability.

<EDIT> And I meant to include that I'm not ecen sure that the "battery detection" is a simple matter of voltage or does that center pin provide some feedback or??? </EDIT>

 

[wtp]

how about just buy another battery and avoid a fire ?!

 

[pghDave]

how about just buy another battery and avoid a fire ?!

So I've always considered the concept of a "hack" to be doing something not necessarily easy or logical but to solve a problem in a different way and a bit of a creative exercise.

Sure, your solution works but where's the adventure?