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My friend just bought a a 10.8v battery for her toshiba satellite that previously used a 14v battery I just need to know if there will be any problems if she uses her new battery.

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Very, very bad idea to deliver the wrong voltage to anything, expensively if it's complex and expensive like a laptop. – Callum Rogers Sep 7 '10 at 12:01
@Callum: Wrong can be relative (in electronics at least). If the battery fit and it was in the range of 13.7 - 14.3 I'd probably use it and not think twice about it. But - 10.8 makes me a bit nervous. – hotei Sep 7 '10 at 16:25

Generally it's a "bad" idea to use anything that isn't a perfect match in terms of voltage.

Over-voltage may damage components (permanently) and should be avoided.

Under-voltage may cause components to be unable to function (but is unlikely to cause permanent damage); it might not work at all, it might work unreliably, it might work fine.

In this case, we're looking at under-voltage - which, as said, might work but I'd personally still recommend against it. And don't forget that the amperage and/or power output of the batteries should be compared as well, it's also important.

If your friend insists on using a weaker battery, I'd advice they turn down all the power settings to the lowest options they can stand.

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You'll never get a "perfect" match and you don't need one. Just remember that as the battery drains the voltage it produces is constantly decreasing. What you need is to be in the range which the laptop is capable of "self-regulating" to the values it needs for proper operation. If the starting voltage point is too low the battery might work for only 15 or 20 minutes. You are right about amperage as that needs to be a good match to the original battery in order to obtain reasonable run times. – hotei Sep 7 '10 at 16:33
@hotei True, "perfect" is a bit strong, most devices will work well in a range ± a few %. But the deviation in the values given by the OP concerns me and I felt that, in this case, an over-cautious post was better than an under-cautious one. – DMA57361 Sep 7 '10 at 16:48
@hotei Considering that the battery is probably a lithium battery, then the voltage drop for the first few minutes is about a volt, then barely anything for the next 80% of the battery, and finally a decrease until the laptop shuts down. (see I'm thinking that with such a difference (14 V vs. 10.8 V), that the laptop won't even turn on. – LDC3 Oct 21 '14 at 6:05

Generally a bad idea if they're that much different. I'm surprised that it would fit. Usually the manufacturers go out of their way to make the cases different if the battery is incompatible with another one in their line. If new battery is not from Toshiba I'd be even more wary.

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For all the non-native speakers: "mfgrs" is short for "manufacturers" – agporwfnz29 Sep 7 '10 at 15:06
@openfkg: Thanks, I got lazy. I've fixed in text now. – hotei Sep 7 '10 at 16:20

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