Reply by Carl September 1, 20212021-09-01
On 9/1/21 4:58 AM, Lasse Langwadt Christensen wrote:
> onsdag den 1. september 2021 kl. 04.22.08 UTC+2 skrev Carl: >> On 8/31/21 5:39 PM, Lasse Langwadt Christensen wrote: >>> tirsdag den 31. august 2021 kl. 23.22.14 UTC+2 skrev Tabby: >>>> On Tuesday, 31 August 2021 at 14:39:26 UTC+1, Ralph Mowery wrote: >>>>> In article <0c1be23f-b5fa-4caa...@googlegroups.com>, >>>>>> On Tuesday, 31 August 2021 at 01:54:20 UTC+1, Mike Perkins wrote: >>>>>>> On 31/08/2021 01:09, Tabby wrote: >>>>>>>> Is there an 18v battery about the size of a C cell? A zener tester, probably 1970s, that goes upto 17v max, takes what looks like a single C cell. There is no circuitry that could up the v as far as I can tell. >>>>>>> https://en.wikipedia.org/wiki/List_of_battery_sizes >>>>>>> >>>>>>> Lookup A412 - 22.5V. I think this was a size used in some AVOs. >>>>>>> >>>>>>> HTH >>>>>> >>>>>> Yes, cheers. I guess 3x PP3 might be a better option now. >>>>>> >>>>>> >>>>> I have a few pieces of older gear that takes batteries that are no >>>>> longer on the market. If there is room I use a 9 volt battery and one >>>>> of the boost converters from China. You can get them to boost or lower >>>>> (buck) the voltage. >>>> I was just wondering about that, but with a 1.5v cell. 9v batteries are a lot more bucks per watthour. >>> >>> https://www.banggood.com/Geekcreit-3_7V-9V-5V-2A-Adjustable-Step-Up-18650-Lithium-Battery-Charging-Discharge-Integrated-Module-p-1264852.html >>> >>> and a LiPo battery >>> >> That has a minimum input of 5V so a single 3.7V Li isn't going to do. > > it is literally designed for a single 3.7V Li, the 4.5-8V input is for the charger >
Sigh, you are right of course. -- Regards, Carl Ijames
Reply by Lasse Langwadt Christensen September 1, 20212021-09-01
onsdag den 1. september 2021 kl. 04.22.08 UTC+2 skrev Carl:
> On 8/31/21 5:39 PM, Lasse Langwadt Christensen wrote: > > tirsdag den 31. august 2021 kl. 23.22.14 UTC+2 skrev Tabby: > >> On Tuesday, 31 August 2021 at 14:39:26 UTC+1, Ralph Mowery wrote: > >>> In article <0c1be23f-b5fa-4caa...@googlegroups.com>, > >>>> On Tuesday, 31 August 2021 at 01:54:20 UTC+1, Mike Perkins wrote: > >>>>> On 31/08/2021 01:09, Tabby wrote: > >>>>>> Is there an 18v battery about the size of a C cell? A zener tester, probably 1970s, that goes upto 17v max, takes what looks like a single C cell. There is no circuitry that could up the v as far as I can tell. > >>>>> https://en.wikipedia.org/wiki/List_of_battery_sizes > >>>>> > >>>>> Lookup A412 - 22.5V. I think this was a size used in some AVOs. > >>>>> > >>>>> HTH > >>>> > >>>> Yes, cheers. I guess 3x PP3 might be a better option now. > >>>> > >>>> > >>> I have a few pieces of older gear that takes batteries that are no > >>> longer on the market. If there is room I use a 9 volt battery and one > >>> of the boost converters from China. You can get them to boost or lower > >>> (buck) the voltage. > >> I was just wondering about that, but with a 1.5v cell. 9v batteries are a lot more bucks per watthour. > > > > https://www.banggood.com/Geekcreit-3_7V-9V-5V-2A-Adjustable-Step-Up-18650-Lithium-Battery-Charging-Discharge-Integrated-Module-p-1264852.html > > > > and a LiPo battery > > > That has a minimum input of 5V so a single 3.7V Li isn't going to do.
it is literally designed for a single 3.7V Li, the 4.5-8V input is for the charger
Reply by Carl August 31, 20212021-08-31
On 8/31/21 5:39 PM, Lasse Langwadt Christensen wrote:
> tirsdag den 31. august 2021 kl. 23.22.14 UTC+2 skrev Tabby: >> On Tuesday, 31 August 2021 at 14:39:26 UTC+1, Ralph Mowery wrote: >>> In article <0c1be23f-b5fa-4caa...@googlegroups.com>, >>>> On Tuesday, 31 August 2021 at 01:54:20 UTC+1, Mike Perkins wrote: >>>>> On 31/08/2021 01:09, Tabby wrote: >>>>>> Is there an 18v battery about the size of a C cell? A zener tester, probably 1970s, that goes upto 17v max, takes what looks like a single C cell. There is no circuitry that could up the v as far as I can tell. >>>>> https://en.wikipedia.org/wiki/List_of_battery_sizes >>>>> >>>>> Lookup A412 - 22.5V. I think this was a size used in some AVOs. >>>>> >>>>> HTH >>>> >>>> Yes, cheers. I guess 3x PP3 might be a better option now. >>>> >>>> >>> I have a few pieces of older gear that takes batteries that are no >>> longer on the market. If there is room I use a 9 volt battery and one >>> of the boost converters from China. You can get them to boost or lower >>> (buck) the voltage. >> I was just wondering about that, but with a 1.5v cell. 9v batteries are a lot more bucks per watthour. > > https://www.banggood.com/Geekcreit-3_7V-9V-5V-2A-Adjustable-Step-Up-18650-Lithium-Battery-Charging-Discharge-Integrated-Module-p-1264852.html > > and a LiPo battery >
That has a minimum input of 5V so a single 3.7V Li isn't going to do. Several years ago I used one of these: https://www.ebay.com/itm/142660988578 "DC-DC Auto Boost Buck step Up step down Converter Module Solar Voltage LM2577" so I could use a single 18500 Li Ion rechargeable to replace a pair of AAA cells. The input ranged from 3.7ish down to 2.7ish as the Li Ion cell discharged (beating the input spec of 3.0V so I was happy) while the output stayed stable at 3.0V where I set it. No, the board and cell didn't fit where the AAA's did, but I was tired of recharging NiMH AAA's every morning after a night of logging pulse and pO2. Anyway, there might be a more modern/cheaper version available now. Oh, the output spec is 1-30V and I chose this model because the input and output ranges can overlap, but with your 22.5V output that isn't a consideration, you just have to find the room for the little board and an 18650 Li cell (unless you want to run it from a 2032 :-)). -- Regards, Carl Ijames
Reply by Ralph Mowery August 31, 20212021-08-31
In article <e2683d29-15d4-45ca-b9a2-9130bd83e277n@googlegroups.com>, 
tabbypurr@gmail.com says...
> > > > I have a few pieces of older gear that takes batteries that are no > > longer on the market. If there is room I use a 9 volt battery and one > > of the boost converters from China. You can get them to boost or lower > > (buck) the voltage. > > I was just wondering about that, but with a 1.5v cell. 9v batteries are a lot more bucks per watthour. > >
It all depends on how much room you have. I don't recall how much but some boost converters have a minimum input voltage. I did use 4 AA batteries in a device that had plenty of room and a boost converter. Not counting the loss for efficency I have found the converters to be almost like a transformer. The power out is about equal to the power in, so if going from a low vlotage to a high voltage you draw more current and if going from a high voltage to a low voltage you draw less courrent.
Reply by Lasse Langwadt Christensen August 31, 20212021-08-31
tirsdag den 31. august 2021 kl. 23.22.14 UTC+2 skrev Tabby:
> On Tuesday, 31 August 2021 at 14:39:26 UTC+1, Ralph Mowery wrote: > > In article <0c1be23f-b5fa-4caa...@googlegroups.com>, > > > On Tuesday, 31 August 2021 at 01:54:20 UTC+1, Mike Perkins wrote: > > > > On 31/08/2021 01:09, Tabby wrote: > > > > > Is there an 18v battery about the size of a C cell? A zener tester, probably 1970s, that goes upto 17v max, takes what looks like a single C cell. There is no circuitry that could up the v as far as I can tell. > > > > https://en.wikipedia.org/wiki/List_of_battery_sizes > > > > > > > > Lookup A412 - 22.5V. I think this was a size used in some AVOs. > > > > > > > > HTH > > > > > > Yes, cheers. I guess 3x PP3 might be a better option now. > > > > > > > > I have a few pieces of older gear that takes batteries that are no > > longer on the market. If there is room I use a 9 volt battery and one > > of the boost converters from China. You can get them to boost or lower > > (buck) the voltage. > I was just wondering about that, but with a 1.5v cell. 9v batteries are a lot more bucks per watthour.
https://www.banggood.com/Geekcreit-3_7V-9V-5V-2A-Adjustable-Step-Up-18650-Lithium-Battery-Charging-Discharge-Integrated-Module-p-1264852.html and a LiPo battery
Reply by Tabby August 31, 20212021-08-31
On Tuesday, 31 August 2021 at 14:39:26 UTC+1, Ralph Mowery wrote:
> In article <0c1be23f-b5fa-4caa...@googlegroups.com>, > > On Tuesday, 31 August 2021 at 01:54:20 UTC+1, Mike Perkins wrote: > > > On 31/08/2021 01:09, Tabby wrote: > > > > Is there an 18v battery about the size of a C cell? A zener tester, probably 1970s, that goes upto 17v max, takes what looks like a single C cell. There is no circuitry that could up the v as far as I can tell. > > > https://en.wikipedia.org/wiki/List_of_battery_sizes > > > > > > Lookup A412 - 22.5V. I think this was a size used in some AVOs. > > > > > > HTH > > > > Yes, cheers. I guess 3x PP3 might be a better option now. > > > > > I have a few pieces of older gear that takes batteries that are no > longer on the market. If there is room I use a 9 volt battery and one > of the boost converters from China. You can get them to boost or lower > (buck) the voltage.
I was just wondering about that, but with a 1.5v cell. 9v batteries are a lot more bucks per watthour.
Reply by Ralph Mowery August 31, 20212021-08-31
In article <0c1be23f-b5fa-4caa-bbab-b681955b651an@googlegroups.com>, 
tabbypurr@gmail.com says...
> > On Tuesday, 31 August 2021 at 01:54:20 UTC+1, Mike Perkins wrote: > > On 31/08/2021 01:09, Tabby wrote: > > > Is there an 18v battery about the size of a C cell? A zener tester, probably 1970s, that goes upto 17v max, takes what looks like a single C cell. There is no circuitry that could up the v as far as I can tell. > > https://en.wikipedia.org/wiki/List_of_battery_sizes > > > > Lookup A412 - 22.5V. I think this was a size used in some AVOs. > > > > HTH > > Yes, cheers. I guess 3x PP3 might be a better option now. > >
I have a few pieces of older gear that takes batteries that are no longer on the market. If there is room I use a 9 volt battery and one of the boost converters from China. You can get them to boost or lower (buck) the voltage.
Reply by Tabby August 31, 20212021-08-31
On Tuesday, 31 August 2021 at 01:54:20 UTC+1, Mike Perkins wrote:
> On 31/08/2021 01:09, Tabby wrote: > > Is there an 18v battery about the size of a C cell? A zener tester, probably 1970s, that goes upto 17v max, takes what looks like a single C cell. There is no circuitry that could up the v as far as I can tell. > https://en.wikipedia.org/wiki/List_of_battery_sizes > > Lookup A412 - 22.5V. I think this was a size used in some AVOs. > > HTH
Yes, cheers. I guess 3x PP3 might be a better option now.
Reply by Phil Allison August 30, 20212021-08-30
Mike Perkins wrote:

=================
>> > Lookup A412 - 22.5V. I think this was a size used in some AVOs.
** That the one that looks like a 9V batt with terminals on each end? IOW the old style hearing aid batt. ... Phil
Reply by Mike Perkins August 30, 20212021-08-30
On 31/08/2021 01:09, Tabby wrote:
> Is there an 18v battery about the size of a C cell? A zener tester, probably 1970s, that goes upto 17v max, takes what looks like a single C cell. There is no circuitry that could up the v as far as I can tell.
https://en.wikipedia.org/wiki/List_of_battery_sizes Lookup A412 - 22.5V. I think this was a size used in some AVOs. HTH -- Mike Perkins Video Solutions Ltd www.videosolutions.ltd.uk