USB powered "fake" battery pack adapter?

[pier4r]

So I tried to search a bit but my question may be a bit too fancy.

I was wondering whether it is possible to have battery compartment with 4 AAA (or 3 or 2, etc..) faked batteries that in reality distribute the power from a usb charger.
Of course a problem could be the voltage. AS the usb is 5V, the batteries are normally ~ 1.2 V .

Anyway, do you know anything similar? I ask this because it is a possibility for me to use more freely calculators like the ti89 , the 1st gen nspire, 49g and others. So far the usb powered systems are the casio with "usb power graphic" label (9860g, 9860gII, various fx-cg10,20,50, etc..), the 50g, the dm42, the prime, numworks and the nspire CX. The list is surely not short, but there are different old models that would be cool to have usb powered as well.

For example the relatively cheap (sometimes) and large voyage 200 and so on.

[Zaphod]

I don’t think any system that would normally take 4 AA or AAA batteries would mind 5volts instead .... you’re only talking ~200mV difference.

You could stick a USB socket on the product and wire the outer two connections directly to the original battery terminals (obviously you’d have to block simultaneous fitment of normal batteries somehow)

Here’s some example sockets you could use https://www.ebay.co.uk/sch/i.html?_from=...t&_sacat=0

[Maximilian Hohmann]

Why not simply buy four rechargeable AAA and four AA cells (Aldi or Lidl in Germany sell them for less than a Euro a piece with 1200/2400 mAh capacity) and a fitting charger? They last for months in a Voyage 200 and similar calculators. No need to tinker around with USB chargers...

As far as for the Ti59 you mention one could certainly remove the dead cells from a battery back and connect a USB charger to the battery leads instead. Maybe with two silicon diodes (1N4001 or similar) in between to lower the voltage from 5V to slightly below 4V. But honestly I found it easier to replace the cells in the pack with modern ones (they have twice or three times the capacity of the original cells) and just use the calculator as it was intended to be used. One good pack is enough for my whole collection, the one that fits the Ti58/Ti59 is also good for the SR-56, SR-52, SR-51 and many others.

[pier4r]

(04-14-2018 12:29 PM)Maximilian Hohmann Wrote:  They last for months in a Voyage 200 and similar calculators. No need to tinker around with USB chargers...

It depends what you do (and the batteries you have). With my usage, that is in burst, they last like one week?

[Maximilian Hohmann]

(04-14-2018 02:32 PM)pier4r Wrote:  It depends what you do (and the batteries you have). With my usage, that is in burst, they last like one week?

What would "burst" be? Anyway, if they last for only one week you charge them for 3 hours and you are good for the next week of bursts...

[HP-Collection]

You you talking on HP41 battery packs or on which pack you are talking?
I use LiPo packs for my HP41 and for my topcat serie..... High power, linear power, easy to recharge

[ijabbott]

(04-14-2018 12:11 PM)pier4r Wrote:  So far the usb powered systems are the casio with "usb power graphic" label (9860g, 9860gII, various fx-cg10,20,50, etc..)

I'm pretty sure those Casios are all powered only by batteries, with the USB connection only being used for data transfer.

[Paul Berger (Canada)]

(04-14-2018 06:13 PM)HP-Collection Wrote:  You you talking on HP41 battery packs or on which pack you are talking?
I use LiPo packs for my HP41 and for my topcat serie..... High power, linear power, easy to recharge

What do you use as a voltage booster in your LiPo pack for you topcat? I have been playing around with the so called "Power Bank" devices. There are some that automatically turn on when a load is applied and turn themselves off when the load goes away. I have one connected to my 97 right now and it works great. This one has two 18650 cells and it would be a pretty tight fit to jam the two cells and the electronics into a battery pack. The only down side of these I can see is that when they run down they will stop without warning.

[pier4r]

(04-14-2018 09:44 PM)ijabbott Wrote:  I'm pretty sure those Casios are all powered only by batteries, with the USB connection only being used for data transfer.

Nope. they can operate on USB only.
https://youtu.be/kqi_42Kyrww

@maximilian. If you check my other posts you see that from time to time I process a lot of data. These activities kill a battery pack also during runtime. While USB power is more reliable.

[Massimo Gnerucci]

(04-14-2018 12:11 PM)pier4r Wrote:  So I tried to search a bit but my question may be a bit too fancy.

I was wondering whether it is possible to have battery compartment with 4 AAA (or 3 or 2, etc..) faked batteries that in reality distribute the power from a usb charger.
Of course a problem could be the voltage. AS the usb is 5V, the batteries are normally ~ 1.2 V .

What about something like this?

[pier4r]

(04-15-2018 09:56 AM)Massimo Gnerucci Wrote:  What about something like this?

Those are a lot of cables to connect on the back of the calculator, but that is exactly the right track! Thanks for the link.

What I was thinking was exactly like a pack of 2,3,4,...,N batteries connected to each other with one plug for a micro usb cable to get the energy constantly. If they recharge, even better, but it is not necessary. They can be also dummy that fits the battery compartment.

[Maximilian Hohmann]

Hello!

(04-15-2018 08:25 AM)pier4r Wrote:  @maximilian. If you check my other posts you see that from time to time I process a lot of data. These activities kill a battery pack also during runtime. While USB power is more reliable.

The pragmatist in me would of course reply that in such cases you picked the wrong tool for the job, but if you really want to run a one-million-loop iteration on your Ti Voyage 200 then help is on hand:

Either the AAA pseudo battery described in the electronics magazine "Elektor" some years ago and also obtainable from them. Unfortunately I do not subscribe to this magazine (only buy it at the train station occasionally) and therefore can not provide the full article, but maybe someone else can?
Here is the article: https://www.elektormagazine.com/magazine...1509/28081
And that is the pseudo battery: https://www.elektor.de/usb-to-aaa-batter...roductLink

An alternative for AA cells is sold at Amazon (but a bit on the expensive side - with a little tinkering skills one could make that for less than 5 Euros at home):
The set consists of one "connector battery" and 7 dummy batteries which will give you quite some flexibility. I have not further researched if similar sets are also solde for AAA cells.
https://www.amazon.de/AA-Mignon-Batterie...B01MDRXHI3

Saluti
Max

[HP-Collection]

(04-14-2018 09:58 PM)Paul Berger (Canada) Wrote:  

(04-14-2018 06:13 PM)HP-Collection Wrote:  You you talking on HP41 battery packs or on which pack you are talking?
I use LiPo packs for my HP41 and for my topcat serie..... High power, linear power, easy to recharge

What do you use as a voltage booster in your LiPo pack for you topcat? I have been playing around with the so called "Power Bank" devices. There are some that automatically turn on when a load is applied and turn themselves off when the load goes away. I have one connected to my 97 right now and it works great. This one has two 18650 cells and it would be a pretty tight fit to jam the two cells and the electronics into a battery pack. The only down side of these I can see is that when they run down they will stop without warning.

I found a DC-DC Step Up Power Supply Module Boost 2-5V to 5V (1200mA). The original cell has 4.8V, so 5V is perfect. Only the card reader is a silly thing as the LiPo booster has problems when the battery gets lower.
You can find thisese boosters on TOS or on Ali

[ijabbott]

(04-15-2018 08:25 AM)pier4r Wrote:  

(04-14-2018 09:44 PM)ijabbott Wrote:  I'm pretty sure those Casios are all powered only by batteries, with the USB connection only being used for data transfer.

Nope. they can operate on USB only.
https://youtu.be/kqi_42Kyrww

@maximilian. If you check my other posts you see that from time to time I process a lot of data. These activities kill a battery pack also during runtime. While USB power is more reliable.

Okay, it seems to work on some older models, but it doesn't work on my fx-CG50. With the batteries removed, and with the calculator plugged into a USB charger, the calculator turns on for a second when the 'ON' button is pressed (just the backlight with a blank screen apart from the 'busy' annunciator in the top right corner), and then turns itself off again.

I'd make a youtube video but I can't be arsed!

[pier4r]

(04-15-2018 11:57 AM)Maximilian Hohmann Wrote:  The pragmatist in me would of course reply that in such cases you picked the wrong tool for the job,

Not at all. You have to consider all the factors. I already replied some months ago to TheKaneB (that seems disappeared) about this.

Do I need to compute something intensive and I have a short deadline? I won't do it on a calculator. I may fire up my laptop or I would buy lambda credits on amazon EC2.

Do I want to solve interesting problems for fun? Well I don't do it on a computer if I can. I try to use embedded or mobile devices.

Do I have computers, although dated, that all the time can solve quite large problems? Yes. Do I solve problems with them? Not really. Why? Because somehow I am not inspired by the setup.
Am I inspired to solve problems with the calculators? Well yes, a lot.

When I see a computer I think "oh, it is used at least for the task X, Y and Z" when I see a calculator, I need to find an interesting problem for me with which it can be used, otherwise it lays there doing nothing. (n1)

Same with android, where fortunately I know I can "torture" every android device that is not anymore my daily driver with the Prime app.

Since there is a huge family of problems a calculator can help me to solve that are also interesting for me (the hard part is to find them through the right question!), I am set for looong time. I wouldn't be committed to do the same with a computer, since, as I said, a computer has already plenty of stuff to do.
Maybe with old and limited computers it can be similar (like a commodore or a 486 or a pentium), but I don't have any.

But for the same reason, sometimes the problem I want to solve it requires time and so I need a long lasting source of energy.

Edit, and the second link about the pseudo battery is super cool! Another great point for the idea. But I don't get it. There is only one active battery and the others are dummies?
For the current there shouldn't be a problem, but if I am not mistaken, shouldn't be there the same voltage for all the slot? If they are just small resistances, wouldn't it be bad?

----
n1: indeed in theory I could use the 50g for all the tasks, instead I try to assign tasks to different devices as I see them fitting.

ti 34 from 1987 -> stats on the bank account. (it is meh for everything else). Note: solar.
sharp 506w -> first calculator of choice. Note: solar.
casio 9860G series -> when the 506w can help but the amount of manual keystrokes are too much. Little programs.
50g -> longer programs and data collection.
prime -> really big problems.
ti 89 -> Tichess (that eats the batteries) . Not yet decided on the rest, depends if I find a usb source.
ti nspire clickpad -> ultra clumsy without the ti software. No USB charge. So far not yet decided. It was an attempt to check if I could have used it for programming when the 50g was at its limits.
free42 -> android / mac , when I don't have the 506w.

Now I think the marginal utility to get other calculators is getting thin, as I don't have much more problems to assign at the moment.

[pier4r]

(04-15-2018 06:05 PM)ijabbott Wrote:  Okay, it seems to work on some older models, but it doesn't work on my fx-CG50. With the batteries removed, and with the calculator plugged into a USB charger, the calculator turns on for a second when the 'ON' button is pressed (just the backlight with a blank screen apart from the 'busy' annunciator in the top right corner), and then turns itself off again.

I'd make a youtube video but I can't be arsed!

Hmm. Are you sure are on the last OS? On the 9860G the USB allowed only connection and no operation without batteries until I upgraded.
The 9860 GII can do the same, both power graphic or power graphic 2.
I am unsure about the 9750, but if there is written "USB power graphic" then it works.

Are you sure the cg10, 20, 50 don't behave like the 9860? Would be heavily suspicious as they are new models that compete with prime and nspire CX that can "survive" on USB power. Let me check.

Hmm I am not finding anything. Nor I find anything for the 9860 where I know that they can survive without batteries but with USB.

[Massimo Gnerucci]

(04-15-2018 08:11 PM)pier4r Wrote:  Maybe with old and limited computers it can be similar (like a commodore or a 486 or a pentium), but I don't have any.

Limited? Hey! Show a little more respect.

Look at what those chips drive, or used to. Besides some of my past computers ...

[pier4r]

(04-15-2018 09:30 PM)Massimo Gnerucci Wrote:  Limited? Hey! Show a little more respect.

Look at what those chips drive, or used to. Besides some of my past computers ...

Cool site! And yes, limited relatively to the current systems if one considers cpu efficiency and ram. (if one would consider, say, ISA ports, the 486 would win hands down)

Of course compared to our trusty calculators those systems wouldn't be limited at all. I guess the 50g should be quite close to a 386 running around 10 mhz with basic or so.

(then again the 50g with listExt was faster than bash on a 266mhz arm in shuffling lists)

[ijabbott]

(04-15-2018 08:13 PM)pier4r Wrote:  

(04-15-2018 06:05 PM)ijabbott Wrote:  Okay, it seems to work on some older models, but it doesn't work on my fx-CG50. With the batteries removed, and with the calculator plugged into a USB charger, the calculator turns on for a second when the 'ON' button is pressed (just the backlight with a blank screen apart from the 'busy' annunciator in the top right corner), and then turns itself off again.

I'd make a youtube video but I can't be arsed!

Hmm. Are you sure are on the last OS? On the 9860G the USB allowed only connection and no operation without batteries until I upgraded.

I'm on OS 3.11, which is very similar to OS 3.10 with just some minor changes for the IB exams.

Quote:Are you sure the cg10, 20, 50 don't behave like the 9860? Would be heavily suspicious as they are new models that compete with prime and nspire CX that can "survive" on USB power. Let me check.

I don't own the older cg20 or cg10 Prizm calculators (which I think are just regional variants of the same calculator) so I don't know. Most of the electronics from the CG10/20 seems to have been retained in the CG50, apart from a faster processor in the CG50.

[brickviking]

(04-14-2018 09:44 PM)ijabbott Wrote:  

(04-14-2018 12:11 PM)pier4r Wrote:  So far the usb powered systems are the casio with "usb power graphic" label (9860g, 9860gII, various fx-cg10,20,50, etc..)

I'm pretty sure those Casios are all powered only by batteries, with the USB connection only being used for data transfer.

At least in my case, I'm able to run my fx-9750gII calculator with the USB cable connected, while I change batteries. I don't think that's unusual, I suspect the fx-9860gII can as well. Of course it's better to run with batteries, as the USB simply won't charge batteries, which perhaps is the important point of this statement.

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