Remove the battery. Then remove the screws from the bottom. Beginning at a front corner, use a very small slotted screw driver to pry the dark grey top from the silver base. Go slowly. The most difficult part to pry open are the two sides of the battery compartment. I did not get the whole keyboard top off, but I was able to open it enough to take the square rechargeable backup battery out. I now have a new question: where can I get a replacement backup battery for the mobilepro 880?
Ok, I'll try that. I'd already tried, and found that the sides of the battery compartment seemed to have an extra screw inside, or some interesting internal latching mechanism - so I just backed away until I could hear from someone who's already done it.
Any part number, model number, etc. on the battery? Electrical characteristics printed on it? (voltage, amperes, etc.) I heard from somewhere that it is a NiCad battery.
There are lots of battery shops that as long as you know the electrical characteristics (you'll need exact voltage, but can go to a higher amperage), and size, they can find them for you (or have them in stock).
The internal latches in the battery compartment are the most difficult. The prongs are on ther dark grey top, so when you wedge the thin screw driver there, you need to push a little as well. As for the battery itself, it is a toshiba F6M. It is actually two F6M batteries joined together. Each has 1.2 volts, 600mAh, and are rechargeable nickel metal hydride. Go to this toshiba link to find the specs: http://www.toshiba-corp.com.tw/e3a.htm
In looking for this battery on the internet, I found out that Toshiba sold their battery division to Sanyo in 2001. Sanyo makes the equivalent. The part # is: HF-D4U. You need to get two and solder them together to make a battery pack. I would think silver solder is needed here. I could not find this battery sold through any store in the US. A few can be order from foreign countries. I emailed a US wholesale distributor for a retail outlet, but it think this is a wholesale type item. I will call NEC customer support to see if they can sell me one. But having said all that, I am not sure that replacing the backup battery will help that much. The 790 uses a 3 volt backup battery, and the 880/890 has two 1.2 volt batteries for a total of 2.4 volts. I suspect that the 0.6 volt difference makes the 790 rom think that your battery is just about to die. So, I'm just going to see how long that low backup battery warning lasts. I have three main battery packs. If the backup battery lasts through three main batteries without pulling the unit into an electrical outlet, then I will not change the backup battery. The warning would then be an annoyance rather than the signal of a real problem. I guess it is also possible to try to find and use a 3 volt lithium ion battery, but this might damage the unit and void the warranty :)
The internal latches in the battery compartment are the most difficult. The prongs are on ther dark grey top, so when you wedge the thin screw driver there, you need to push a little as well. As for the battery itself, it is a toshiba F6M. It is actually two F6M batteries joined together. Each has 1.2 volts, 600mAh, and are rechargeable nickel metal hydride. Go to this toshiba link to find the specs: http://www.toshiba-corp.com.tw/e3a.htm
In looking for this battery on the internet, I found out that Toshiba sold their battery division to Sanyo in 2001. Sanyo makes the equivalent. The part # is: HF-D4U. You need to get two and solder them together to make a battery pack. I would think silver solder is needed here. I could not find this battery sold through any store in the US. A few can be order from foreign countries. I emailed a US wholesale distributor for a retail outlet, but it think this is a wholesale type item. I will call NEC customer support to see if they can sell me one. But having said all that, I am not sure that replacing the backup battery will help that much. The 790 uses a 3 volt backup battery, and the 880/890 has two 1.2 volt batteries for a total of 2.4 volts. I suspect that the 0.6 volt difference makes the 790 rom think that your battery is just about to die. So, I'm just going to see how long that low backup battery warning lasts. I have three main battery packs. If the backup battery lasts through three main batteries without pulling the unit into an electrical outlet, then I will not change the backup battery. The warning would then be an annoyance rather than the signal of a real problem. I guess it is also possible to try to find and use a 3 volt lithium ion battery, but this might damage the unit and void the warranty :)
Ok - looked at it. Wonder if there is enough room for a couple of AAA NiMH batteries? Would AAA batteries fit? They are 10mm diameter and 45mm long. They are nominally 1.2V, and provide 600mAh.
If there's enough room, you could solder a couple of those together and tape them together, use a dab of silicone to keep them from moving.
You may be right about the 3V threshold. Although it's odd to have a "battery" of 2.4V. It MIGHT take a 3V lithium, but I don't know that I'll try it on mine. [:D]
I just got an email from NEC that they won't sell me a backup battery. The AAA batteries are too big. The dimension of the backup battery is 35mm by 35mmmm and only 6.6mm high. You can find rechargeable nmh batteries with the proper volts and amps, but it's the size that is difficult to find. The best site to check for rechargeable batteries and that will sell to the public is www.mouser.com. They sell almost everything, but they don't sell the Sanyo HF-D4U. I am looking at a rechargeable lithium ion coin cell battery they have in stock. It is made by Varta, and has solder leads on them, under $2.00. But it is 3 volts and 250mAh. If the additional volts work, then the 250mh should last about 3 days with a dead battery.
Ok, I'm working a couple of sources that I have had good success with getting odd batteries in the past. Keep you posted.
If your 880 is still apart, I'd REALLY appreciate some digital photos of where the latches, etc. are internally. Hopefully keep me from breaking mine when I get it apart.
Might even get Richard to either host the pics and disassembly instructions, or post a link to a site they could be put on.
I already put the mobilepro 880/890 back together. I use it everyday and find myself using my laptop less and less. If I have time, I'll open it again. But it will be hard to take pictures, because I could not disassemble the top off completely. All I could do was open it enough to get the battery out. The battery is located at the front left corner. So I opened it about 2 inches and took it out.
I think a 3 volt battery will work. I would assume the 880 is very similar to the 780/790. Since the 780/790 takes a 3 volt backup lithium ion coin type battery, I would assume the 880 can as well. 0.6 volt difference is not much. I might try the experiment tonight. I have a spare Panasonic rechargeable 780 backup lithium ion coin battery with solder leads, but only 100mAh. If you see me bidding on another 880 on Ebay, you will know that I fried mine :)
quote:Originally posted by red99cat
I think a 3 volt battery will work. I would assume the 880 is very similar to the 780/790. Since the 780/790 takes a 3 volt backup lithium ion coin type battery, I would assume the 880 can as well. 0.6 volt difference is not much. I might try the experiment tonight. I have a spare Panasonic rechargeable 780 backup lithium ion coin battery with solder leads, but only 100mAh. If you see me bidding on another 880 on Ebay, you will know that I fried mine :)
Let me know how it goes. I'd much rather have an easy-to-find replacement battery for the future (if it's ever needed again). When you pop it open tonite, I'd appreciate a few digital photos to see where the latches are. I figured it would only need to be "cracked open" to access the battery.
Found out that there are 2 batteries available (special order):
Sanyo HF-C1U it is 1.2V, 600mAh, 6.1mm x 17mm x 35mm @ $3.95/ea
Sanyo HF-B1UX is 1.2V, 800mAh, 6.1mm x 17mm x 48mm @ $3.49/ea
2 of the HF-C1U, would be a couple of mm wider, and 1mm longer than the original, but a bit thinner.
If you DO fry yours, I did see that b-portable has NIB 880s for $249 on ebay.
Great news! I went for it tonight and put a 3 volt into the 880, and it is working great so far. No more low battery warning. I took the backup battery out of my 780 (the 780 is much easier to take apart), and put it in the 880/890. It has the same adapter fitting. I took pictures. One is of the 880/890 turned on with the 3 volt backup battery hanging out the side. It is running on battery power. The screen, if you look closely indicates that the internal battery is good. The square green battery in the middle is the original 2.4 volt 880 battery. The second picture is a side view from the battery compartment. You can see the prongs. Be sure to push the pcmcia button in when separating the keyboard piece. If the whole thing recharges without blowing up, I will look for a 3 volt rechargeable lithium ion coin battery with the greatest amount of mAh. I'll try to send you the two pictures via email if I can find your address through this message board.
After 4 days of using the 880/890 with the upgraded 3 volt backup battery, everything is still working great. No more low interal battery warnings. Recharges and stops recharging with no problem. Also 790 rom in a 880 is great. The upgraded 4.0 iexplorer allows me to use the 890 to get on the internet and get my email when I travel. My $8 ebay Cisco Aironet 340 wireless pcmcia lan card works fine. And after an installation adjustment that was not found in any documentation, my $15 ebay Apollo Compact Flash Ethernet card works without a glitch. The normal webpages are slows, but when you get on to the many specially designed streamlined text only pocketpc sites, like the ones for yahoo email and NY times, espn, the screen refresh is almost instantaneous. If you upgrade the 880 rom, I highly recommend the backup battery change. I used a Panasonic VL-3032-1f2 from Mouser.com. It cost $9.23.
Thanks to all who have posted in this topic and elsewhere about how to convert an 880 to an "890". About a year ago when the battery was completely discharged on my 790 and I was too busy to reinstall all my apps, I started carrying my laptop "temporarily" and never went back because of the screen size. I considered buying an 880 but did not do so because of the older OS. Now I have ordered one of the NIB 880s on eBay and will convert it as soon as it comes in.
Red99cat, I also would like a copy of any photos you have re disassembling the 880 -- my email address is in my profile. I will make a point to take shots during my conversion and make them available. Thanks.
Although this topic forum has been closed for a while.,I just wanted add that this suggestion of "redcat's' does work.,I just replaced the backkup square battery in my 880 with a coin size 3v Panasonic VL-3032-1f2 from Mouser.com.,not hard to replace at all.,and I've got the upgraded 790 memory chip in mine also with no problems.
The MP800 came standard with the 3v backup battery, same as the 770-790 series. The MP880 is the one with the unusual backup battery. So if you have an old 800 lying around, it is a simple trick to unplug it and put it in your 880.
Using the 3v battery in a stock 880 causes no problems whatsoever, and if you decide to use the 790 rom chip for the 890 hack, then you will be all set.
The only limiting factor is the backup current supply. A stock 880 will retain its memory if the mian battery is unplugged for quite a while whereas the little 3v backup battery if used will only last an hour or two.
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red99cat
Remove the battery. Then remove the screws from the bottom. Beginning at a front corner, use a very small slotted screw driver to pry the dark grey top from the silver base. Go slowly. The most difficult part to pry open are the two sides of the battery compartment. I did not get the whole keyboard top off, but I was able to open it enough to take the square rechargeable backup battery out. I now have a new question: where can I get a replacement backup battery for the mobilepro 880?
tundrwd
Ok, I'll try that. I'd already tried, and found that the sides of the battery compartment seemed to have an extra screw inside, or some interesting internal latching mechanism - so I just backed away until I could hear from someone who's already done it.
Any part number, model number, etc. on the battery? Electrical characteristics printed on it? (voltage, amperes, etc.) I heard from somewhere that it is a NiCad battery.
There are lots of battery shops that as long as you know the electrical characteristics (you'll need exact voltage, but can go to a higher amperage), and size, they can find them for you (or have them in stock).
red99cat
The internal latches in the battery compartment are the most difficult. The prongs are on ther dark grey top, so when you wedge the thin screw driver there, you need to push a little as well. As for the battery itself, it is a toshiba F6M. It is actually two F6M batteries joined together. Each has 1.2 volts, 600mAh, and are rechargeable nickel metal hydride. Go to this toshiba link to find the specs:
http://www.toshiba-corp.com.tw/e3a.htm
In looking for this battery on the internet, I found out that Toshiba sold their battery division to Sanyo in 2001. Sanyo makes the equivalent. The part # is: HF-D4U. You need to get two and solder them together to make a battery pack. I would think silver solder is needed here. I could not find this battery sold through any store in the US. A few can be order from foreign countries. I emailed a US wholesale distributor for a retail outlet, but it think this is a wholesale type item. I will call NEC customer support to see if they can sell me one. But having said all that, I am not sure that replacing the backup battery will help that much. The 790 uses a 3 volt backup battery, and the 880/890 has two 1.2 volt batteries for a total of 2.4 volts. I suspect that the 0.6 volt difference makes the 790 rom think that your battery is just about to die. So, I'm just going to see how long that low backup battery warning lasts. I have three main battery packs. If the backup battery lasts through three main batteries without pulling the unit into an electrical outlet, then I will not change the backup battery. The warning would then be an annoyance rather than the signal of a real problem. I guess it is also possible to try to find and use a 3 volt lithium ion battery, but this might damage the unit and void the warranty :)
tundrwd
Ok - looked at it. Wonder if there is enough room for a couple of AAA NiMH batteries? Would AAA batteries fit? They are 10mm diameter and 45mm long. They are nominally 1.2V, and provide 600mAh.
If there's enough room, you could solder a couple of those together and tape them together, use a dab of silicone to keep them from moving.
You may be right about the 3V threshold. Although it's odd to have a "battery" of 2.4V. It MIGHT take a 3V lithium, but I don't know that I'll try it on mine. [:D]
red99cat
I just got an email from NEC that they won't sell me a backup battery. The AAA batteries are too big. The dimension of the backup battery is 35mm by 35mmmm and only 6.6mm high. You can find rechargeable nmh batteries with the proper volts and amps, but it's the size that is difficult to find. The best site to check for rechargeable batteries and that will sell to the public is www.mouser.com. They sell almost everything, but they don't sell the Sanyo HF-D4U. I am looking at a rechargeable lithium ion coin cell battery they have in stock. It is made by Varta, and has solder leads on them, under $2.00. But it is 3 volts and 250mAh. If the additional volts work, then the 250mh should last about 3 days with a dead battery.
tundrwd
Ok, I'm working a couple of sources that I have had good success with getting odd batteries in the past. Keep you posted.
If your 880 is still apart, I'd REALLY appreciate some digital photos of where the latches, etc. are internally. Hopefully keep me from breaking mine when I get it apart.
Might even get Richard to either host the pics and disassembly instructions, or post a link to a site they could be put on.
red99cat
I already put the mobilepro 880/890 back together. I use it everyday and find myself using my laptop less and less. If I have time, I'll open it again. But it will be hard to take pictures, because I could not disassemble the top off completely. All I could do was open it enough to get the battery out. The battery is located at the front left corner. So I opened it about 2 inches and took it out.
I think a 3 volt battery will work. I would assume the 880 is very similar to the 780/790. Since the 780/790 takes a 3 volt backup lithium ion coin type battery, I would assume the 880 can as well. 0.6 volt difference is not much. I might try the experiment tonight. I have a spare Panasonic rechargeable 780 backup lithium ion coin battery with solder leads, but only 100mAh. If you see me bidding on another 880 on Ebay, you will know that I fried mine :)
tundrwd
Let me know how it goes. I'd much rather have an easy-to-find replacement battery for the future (if it's ever needed again). When you pop it open tonite, I'd appreciate a few digital photos to see where the latches are. I figured it would only need to be "cracked open" to access the battery.
Found out that there are 2 batteries available (special order):
Sanyo HF-C1U it is 1.2V, 600mAh, 6.1mm x 17mm x 35mm @ $3.95/ea
Sanyo HF-B1UX is 1.2V, 800mAh, 6.1mm x 17mm x 48mm @ $3.49/ea
2 of the HF-C1U, would be a couple of mm wider, and 1mm longer than the original, but a bit thinner.
If you DO fry yours, I did see that b-portable has NIB 880s for $249 on ebay.
red99cat
Great news! I went for it tonight and put a 3 volt into the 880, and it is working great so far. No more low battery warning. I took the backup battery out of my 780 (the 780 is much easier to take apart), and put it in the 880/890. It has the same adapter fitting. I took pictures. One is of the 880/890 turned on with the 3 volt backup battery hanging out the side. It is running on battery power. The screen, if you look closely indicates that the internal battery is good. The square green battery in the middle is the original 2.4 volt 880 battery. The second picture is a side view from the battery compartment. You can see the prongs. Be sure to push the pcmcia button in when separating the keyboard piece. If the whole thing recharges without blowing up, I will look for a 3 volt rechargeable lithium ion coin battery with the greatest amount of mAh. I'll try to send you the two pictures via email if I can find your address through this message board.
red99cat
After 4 days of using the 880/890 with the upgraded 3 volt backup battery, everything is still working great. No more low interal battery warnings. Recharges and stops recharging with no problem. Also 790 rom in a 880 is great. The upgraded 4.0 iexplorer allows me to use the 890 to get on the internet and get my email when I travel. My $8 ebay Cisco Aironet 340 wireless pcmcia lan card works fine. And after an installation adjustment that was not found in any documentation, my $15 ebay Apollo Compact Flash Ethernet card works without a glitch. The normal webpages are slows, but when you get on to the many specially designed streamlined text only pocketpc sites, like the ones for yahoo email and NY times, espn, the screen refresh is almost instantaneous. If you upgrade the 880 rom, I highly recommend the backup battery change. I used a Panasonic VL-3032-1f2 from Mouser.com. It cost $9.23.
BruceHungerford
Thanks to all who have posted in this topic and elsewhere about how to convert an 880 to an "890". About a year ago when the battery was completely discharged on my 790 and I was too busy to reinstall all my apps, I started carrying my laptop "temporarily" and never went back because of the screen size. I considered buying an 880 but did not do so because of the older OS. Now I have ordered one of the NIB 880s on eBay and will convert it as soon as it comes in.
Red99cat, I also would like a copy of any photos you have re disassembling the 880 -- my email address is in my profile. I will make a point to take shots during my conversion and make them available. Thanks.
Bruce
Bruce
MP890 Evangelist
tundrwd
I plan to do the same (take pictures) when I get to it. Hopefully, we can wind up with a set of photos to help others disassemble their units.
uc4ictbl
Although this topic forum has been closed for a while.,I just wanted add that this suggestion of "redcat's' does work.,I just replaced the backkup square battery in my 880 with a coin size 3v Panasonic VL-3032-1f2 from Mouser.com.,not hard to replace at all.,and I've got the upgraded 790 memory chip in mine also with no problems.
zippytex
Does anyone have those pictures of the battery replacement for mobilepro 880? Thanks
Rich Hawley
Moderator
I never took pictures of the square battery, but this might help you with the disassembly...
http://hpcnec.com/cgi-bin/hpcnec.cgi?fid=14&topic_id=1204492075
The stock battery is the ivc2025c as shown in the diagram...
Rich
HPCNEC.COM
Rich Hawley - Handheld PC Fanatic
HPCNEC.COM
Rich Hawley
Moderator
Just another note:
The MP800 came standard with the 3v backup battery, same as the 770-790 series. The MP880 is the one with the unusual backup battery. So if you have an old 800 lying around, it is a simple trick to unplug it and put it in your 880.
Using the 3v battery in a stock 880 causes no problems whatsoever, and if you decide to use the 790 rom chip for the 890 hack, then you will be all set.
The only limiting factor is the backup current supply. A stock 880 will retain its memory if the mian battery is unplugged for quite a while whereas the little 3v backup battery if used will only last an hour or two.
Rich Hawley - Handheld PC Fanatic
HPCNEC.COM
Rich Hawley - Handheld PC Fanatic
HPCNEC.COM