Hi, Did you find this actual battery on Mouser? I could only find other non-stocked Panasonic batteries. As for the clock idea to be honest at that point I can just pick up the Chinese generic brand. -Ali -----Original Message----- From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Rich Cini Sent: Tuesday, September 09, 2014 10:25 AM To: General Discussion: On-Topic and Off-Topic Posts Subject: Re: Replacement NiCd Rechargeable Batteries for SemiDisk Card Digi-Key and Mouser show it as non-stock. What I did on my QT Clock board was find a cordless phone battery pack on eBay with similar specs and hack it apart. Works fine. Rich Cini Sent from my iPhone Googlefu did not turn up anything. batteries:

On Tue, 9 Sep 2014, Rich Cini wrote: I've had a hard time finding a lot of replacement NiCd types that were once very common. I was told a lot of it is due to RoHS because manufacturers have stopped using them and have switched to "less toxic" (sure...) NiMH and Li-ion for new manufacture. I've replaced some NiCd batteries with NiMH, but I wouldn't recommend it in a backup application because of the high rate of self-discharge that most NiMH batteries suffer plant was sold to FDK in 2009 when Panasonic bought out the rest of Sanyo. Try searching for FDK Twicell. https://encrypted.google.com/search?hl=en&q=FDK+Twicell

Chuck, No it is nothing that sophisticated. It is just a standard RAM board with circuitry and BIOS to emulate a HDD. Here is the only blurb I could find on it online: "Solid-state disk emulator The Blue Flame III solid-state, nonvolatile disk emulator boosts access speed by up to 20 times. The DOS compatible card is an I/O mapped device built from 14 SIMMs. It features a 16bit data path and transfers data up to 4 Mbytes/s. Capacities range from 2 to 56 Mbytes. Each card fits in a full length, I6-bit ISA bus slot. Semi Disk Systems; from $595." Based on this info it seems to max out at 4MB 30 pin SIMMs. I am guessing this was initially because of a lack or expense of 16MB SIMMs. I wonder if the BIOS would support a board full of 16MB SIMMs? In any case it is a pretty neat card although simple. I think the NiCd batteries, which are soldered on BTW, are for when you need to move the card attach an external battery (included) with a charger. I am sure that battery is dead as well but that is another story. The Supercapacitor is an interesting idea. I wonder if cost is what is keeping people from using it on mother boards to replace coin batteries. Worse comes to worst I will use the generic Chinese battery. I just worry about no name batteries in a device where I don't have direct visualization. -----Original Message----- From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Chuck Guzis Sent: Tuesday, September 09, 2014 11:00 AM To: General Discussion: On-Topic and Off-Topic Posts Subject: Re: Replacement NiCd Rechargeable Batteries for SemiDisk Card On 09/09/2014 09:28 AM, Ali wrote: Googlefu did not turn up anything. batteries: If it's SRAM and a rechargeable battery, I might be tempted to substitute a "keeper" supercap. Here's a paper from Cooper-Bussman: http://www.digikey.com/Web%20Export/Supplier%20Content/CooperBussmann_283/PD F/CooperBussmann_PowerStor_KSeries.pdf?redirected=1 Some of the pinball folks are using Panasonic supercaps for SRAM backup supplies and report retention times on the order of 45 days between power cycles. If that's enough for you, then you may want to consider using a component that doesn't have the liability of leaking. Another alternative is to simply use a primary battery, such as a couple of AA alkaline cells and a Shottky diode or MOSFET to block the reverse (charge) current. An AA in this application should last its shelf life. I've got a couple of old systems set up with AAs that are still going strong after 10 years. The added advantage is that you can separate the battery from the device to avoid damage should the battery leak. I've wondered about the use of a solar cell operating off of normal room lighting and a supercap for memory/RTC retention. If you stash your equipment in a dark closet, that's maybe not a good idea, however. --Chuck

Tony, It actually uses five of these batteries. I am guessing they are in series to produce 5V (okay 6V) needed for the SIMMs at 250mAh. If the point of the battery is just for use during system swap/maintenance 1-2 hours is plenty of time. Especially considering that once it is out of the system you can connect it again to the big battery. As Tothwolf said it may just be that they are not manufacturing them any more for use. Or that the 250mAh batteries just don't last long enough for newer applications. I think what I may end up doing is trying to see how well the batteries charge up as it stands. If I can get a few minutes out of them I am good. If not I am considering swapping them out for either 300 mAh or 400 mAh batteries and just having a longer charge time (but also longer "backup time"). -Ali -----Original Message----- From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Tony Duell Sent: Tuesday, September 09, 2014 2:25 PM To: cctalk at classiccmp.org Subject: Re: Replacement NiCd Rechargeable Batteries for SemiDisk Card If it uses SIMMs, which are DRAM, thgen not only msut the SIMMs be powered to retain the data, but there mus also be some logic -- running -- to refresh them. That could take considerable current. A 250mA battery is not going to keep that running for vrey long (I would guess 1-2 hours at most). So I think you're right. The batterty is just there topreserve the memory contents when other suppleis (PC power supply, external battery pack) are not. -tony

Yes, leakage is a big concern. One of the batteries has a little something coming out on closer inspection so it may be time for them to go even if they work well. Thanks for the tip on BYD. My concern in using a different type of battery is the charger circuitry. I have read that a NiCd charger can ruin NiMh batteries very quickly (and explode Li Ion ones). So I'd like to stay with the NiCd for as long as possible. -Ali -----Original Message----- From: cctalk-bounces at classiccmp.org [mailto:cctalk-bounces at classiccmp.org] On Behalf Of Tothwolf Sent: Wednesday, September 10, 2014 8:56 AM To: General Discussion: On-Topic and Off-Topic Posts Subject: RE: Replacement NiCd Rechargeable Batteries for SemiDisk Card If they are as old as you mentioned in your initial post, I wouldn't keep them around. Nicds that old tend to leak at random and corrode pc boards. Try searching for a 2/3AA. I think that is the size you are looking for. You might also try searching for BYD brand batteries. They are one of the major manufacturers for nickle based batteries and may very well have what you are looking for. If the batteries are only being used for short term backup, a NiMH would probably work ok.