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General Vintage Technology Discussions For general discussions about vintage radio and other vintage electronics etc. |
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27th Feb 2019, 1:33 pm | #1 |
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Looking for C and D rechargeable batteries 1.5 Volts
I am looking for a couple of type D and C rechargeable battery but 1,5 volts instead of 1,2 volts
Does anyone knows if they are available and where? Thanks |
27th Feb 2019, 1:46 pm | #2 |
Nonode
Join Date: Jan 2010
Location: North Somerset, UK.
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Re: Looking for d and c rechargeable batteries 1,5 volts
I am not aware of any generally available rechargeable battery technology that gives a nominal 1.5 volts.
1.2 volts is common. 2 volts and 3.7 volts exist using lead acid or lithium technology, but both are uncommon in C or D cell sizes. Alkaline cells are of course 1.5 volts and some types claim to be rechargeable, but with very mixed results. 1.2 volt rechargeable cells will often serve instead of 1.5 volts because the voltage of a disposable cell falls in use, and in a high drain appliance may in fact average about 1.2 volts. In low drain applications however the disposable cells will have a higher voltage for most of the life. Note for example that valves intended for dry battery operation often have 1.4 volt heaters, not 1.2 volt. Under the modest load of a small valve heater, 1.4 volts would be a fair average. A relatively high current torch bulb would traditionally be rated at 1.2 volts per cell, again a fair average at the higher discharge current. Do you have a particular application in mind ? |
27th Feb 2019, 3:10 pm | #3 |
Heptode
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Re: Looking for d and c rechargeable batteries 1,5 volts
If you don't mind lithium, there is the popular 18650 (AA size)
1 will give you 3.6 volts. |
27th Feb 2019, 3:22 pm | #4 |
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Re: Looking for d and c rechargeable batteries 1,5 volts
Most battery (cell) manufacturers specify 0.9V per cell as the end voltage and therefore equipment designed to use said cells should work down to this voltage per cell. I have never had a problem using 1.2V (nominal, very nominal) rechargeables in any bit of battery powered kit. The discharge curve of a NiMh cell is much flatter than an Alkaline type giving about the same life as an alkaline.
Why do you need 1.5V? BTW 18650 is much bigger than an AA 18mm diameter and 65mm long, an AA is 15mm diameter and 50mm long. The curious 3 digits for length stems from the definition of coin cells where a 2032 is 20mm diameter and 3.2mm thick. |
27th Feb 2019, 3:31 pm | #5 |
Octode
Join Date: Feb 2018
Location: Southampton, Hampshire, UK.
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Re: Looking for d and c rechargeable batteries 1,5 volts
18650 is much larger than a standard AA battery. Purely as far as size is concerned, 14500 is closest to a AA. Of course, the voltage is much higher i.e. 4.2V fully charged as opposed to 1.6V or so for a fresh AA battery.
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27th Feb 2019, 3:59 pm | #6 |
Octode
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Location: Southampton, Hampshire, UK.
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Re: Looking for d and c rechargeable batteries 1,5 volts
I have been using these 1.2V rechargeable D size batteries for one of my radios and find them quite good. Using a fuse is always recommended though due to the high amounts of energy they store.
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27th Feb 2019, 4:08 pm | #7 |
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Re: Looking for d and c rechargeable batteries 1,5 volts
The nominal cell voltage depends on the chemistry involved. I'm not aware of any rechargeable battery chemistry that gives a 1.5V voltage.
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27th Feb 2019, 4:47 pm | #8 |
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Re: Looking for d and c rechargeable batteries 1,5 volts
Thanks to everybody.
I was tired of buying batteries for differents devices, so I decided to use only rechargeable ones for everything in the house, my old maglite, toys, radios, remote controllers, etc. Now I am thinking in using them in my workshop equipment so I will use them in my Avos and others multimeters, capacimetres, etc. In the case of the Avos, an other multimeters (d or c and A cells are involved) I wonder if that difference of 0,3 volts will affect the accuracy of the device on ohms readings. Thanks |
27th Feb 2019, 5:12 pm | #9 |
Dekatron
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Location: Worksop, Nottinghamshire, UK.
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Re: Looking for d and c rechargeable batteries 1,5 volts
The ohms range will be fine until the battery is so flat that you can't zero the pointer any more. It is a current based measurement and battery voltage is not important.
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27th Feb 2019, 5:19 pm | #10 | |
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Re: Looking for d and c rechargeable batteries 1,5 volts
Quote:
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27th Feb 2019, 8:49 pm | #11 |
Dekatron
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Location: Wiltshire, UK.
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Re: Looking for d and c rechargeable batteries 1,5 volts
Panasonic did a range of "Eneloop" rechargeable cells that were supposedly 1.5V per cell.
https://www.panasonic.com/global/con...hnologies.html Maplin used to sell them: I did have a background-plan to buy a batch of these to try in my AOR AR1000 scanner-radio, which was clearly designed to have the full Alkaline 1.5V-per-cell and suffers rapidly-declining sensitivity when powered from AA rechargeable NiMH or Li-Ion cells which start-out at 1.4V when fully-charged and soon settle to 1.2 or 1.3V (if you're lucky) once discharge commences. |
27th Feb 2019, 11:09 pm | #12 |
Dekatron
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Location: Brentwood, Essex, UK.
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Re: Looking for d and c rechargeable batteries 1,5 volts
My Sony ICF -SW35 which uses three AA cells, stops working at about 4V. At home, I use it with an external battery pack, three alkaline D cells in a Maplin three cell holder and a short flying lead, so only using the internal cells when I take it out.
The manual of a 1970 flash gun I used to have that took four AA cells warned you not to use NiCads. I did wonder if this was because the flash gun relied on the internal resistance of contemporary disposable batteries to limit the surge current at the start of charging, because it still worked, but more slowly, with partly run-down batteries giving less than 1.2V/cell. |
3rd Mar 2019, 2:03 pm | #13 | |
Dekatron
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Location: Leominster, Herefordshire, UK.
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Re: Looking for d and c rechargeable batteries 1,5 volts
Quote:
That article does suggest that Eneloop voltage is higher than a typical NiMH cell, but the discharge graph on load only suggests that about 1.3V is the on load voltage for most of the time. That is well above the "comparable" alkaline cell voltage except for about the first 10-20% of the alkaline's discharge. The load chosen (500mA) is quite heavy for an AA alkaline, though, presumably to show the Eneloops in the most favourable light.
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3rd Mar 2019, 2:26 pm | #14 |
Dekatron
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Location: Worksop, Nottinghamshire, UK.
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Re: Looking for d and c rechargeable batteries 1,5 volts
I have found that those "matchbox" SD card MP3 players only work for a short time on HiMh batteries but are fine on disposables.
They must cut off at 1.2 or 1.3 volts. |
4th Mar 2019, 1:45 pm | #15 | |
Nonode
Join Date: Jan 2010
Location: North Somerset, UK.
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Re: Looking for d and c rechargeable batteries 1,5 volts
Quote:
Alternatively, many consumer grade appliances that work fine on rechargeables, still carry a warning "do not use rechargeable cells" This is for product liability reasons. If the appliance suffers a gross fault that causes a short circuit, then a rechargeable battery can supply enough current to start a fire. Disposable batteries wont normally supply enough current to start a fire, though there is some slight risk with multiple large cells. In the extreme case of equipment approved for use in flammable atmospheres, the instructions may state "zinc carbon cells only" due to the greater current available from alkaline cells. |
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4th Mar 2019, 2:04 pm | #16 |
Dekatron
Join Date: Feb 2007
Location: Leominster, Herefordshire, UK.
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Re: Looking for C and D rechargeable batteries 1.5 Volts
Sounds like a sneaky wired in picofuse or similar would take care of that problem.
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5th Mar 2019, 12:37 am | #17 |
Nonode
Join Date: Jan 2010
Location: North Somerset, UK.
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Re: Looking for C and D rechargeable batteries 1.5 Volts
Yes, but at a cost of several pence !
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5th Mar 2019, 11:33 am | #18 |
Dekatron
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Location: Leominster, Herefordshire, UK.
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Re: Looking for C and D rechargeable batteries 1.5 Volts
I was thinking more of aftermarket mods than original build......
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