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There are aftermarket batteries for vintage models that do not copy apples logo, such as the Rayovac ones for the original MacBook. The statement about batteries from demo machines running in stories is incredulous. Seriously suggesting that customers want repairs with batteries that have been trickle charged while continuously running, as would be the case for batteries from demo units, just fails Occam's razor. Story sounds like someone that is complaining after they got caught or at least should have done more research into their supplier.

It's good to perform a test load on them once in a while, but even if you don't, 5 years and they'll need to be replaced; if not to address a potential hazard. They're lead acid cells. They dry out, bloat, and in some cases vent violently!.

Some consumer grade UPS units are so cheap that it makes no sense to replace just the battery. With those, you're better off replacing the whole thing as all the internal components wear out with age to. But, if you wish to go with a generic replacement battery assuming you know the cell type, Batteries Plus is a good place to start.

Now only if there were service offerings where you could have someone replace the battery on your iPad. Some of which can do it while you wait for 5 - 10 minutes.

If only.

But that still won't stop people from bitching I suppose.

I'm rarely one to shill a store or product, but I've used Batteries Plus stores for customers who are in the same exact situation you are in. I believe they are owned by Rayovac.

Typically their generic laptop/cell phone batteries end up being cheaper than the name brand units (although this isn't always the case). For people in your case, though, this is really the only option for a fresh battery for an older laptop, cell phone, etc.

They're a franchise much like Radio Shack so you should be able to find one somewhere near you.

How many people recycle their alkaline batteries I ask?

I spent the last two years saving my used alkaline batteries. When i took them into the local Batteries Plus, the guy behind the counter tossed them into the trash can.

If you are near one - http://www.batteriesplus.com/ recycles ALL battery chemistries for free. And I mean, you can recycle a couple boxes. A pallet - well, that will have usually a $50 - $75 surcharge for driving a truck out to pick them up.

If the typical current draw of a system is known, discerning the required battery is pretty straight forward. Sealed lead acid batteries are the least expensive and best performing way to go when it comes to relative performance. I cannot recommend any specifically efficient hardware, but I suspect that 'new' and 'mobile' will be the operative words in portable all-day systems, and those two usually indicate 'pricey' as well.

The largest sealed lead acid standard out there is 80 amp-hour. 80AH batteries are ginormous and probably excessive. Something like a 33AH SLA battery (pdf spec sheet) will probably hold up all day and is portable by nature. The battery usually has a handle as part of the case and weighs about 25 pounds. It is typically found powering a wheelchair. Sealed lead acid batteries like to deliver current, absorbed glass mat (AGM) varieties handle abuse, and they are designed to have regular discharge-charge cycles while handling overcharging. As far as power density goes, they are the most cost effective. Replacements will be readily available. Their size and shape lend the battery to being mounted to things (like desks). SLA 33AH AGM batteries are almost exactly automotive group U1 size, which are used in small tractors, so ABS plastic casings and brackets are widely available.

If your systems have a known average power consumption, all you need to do is multiply current at 12V (amps) by desired run time (hours), and add 20% to allow for battery aging or heavy use. Round up to the next highest battery capacity in amp hours. Simple stuff, I know. The next step will be your charging procedures. While batteries can be chained in parallel and charged, the best way is for each to be charged independently. You will have to consider the time allowed for each battery to charge against its capacity to discern the correct charging solution. For a 33AH battery, a charger that can achieve 6 or 7 amps per battery is ideal but it needs to be automatic. If a second set of batteries is added per system, a 3/4 amp non-automatic charger could be employed as other batteries are in use; battery "tenders" are commonly used for motorcycles and such and are inexpensive. The charging systems would be a near-one-time cost and the main expense would be the biannual replacement of derelict batteries.

IANA battery engineer, just a tech, but I hope this sheds some light. as an aside, NICD and NIMH cells are rated to 1.2 volts per cell, and Li-Ion/Li-Poly are 3.6 volts per cell. I sincerely doubt that a lithium based powered solution could be cost effective, because nobody can service them and they are not widely available in non-proprietary formats. Cool idea!

I've used Batteries Plus to replace the batteries in my UPSs. They have the correct batteries for different types of UPSs and have been pretty reasonable on prices. They're a franchise so they're all over the US.

These guys are pretty cool. If there's one near you, they'll assemble battery packs for you. -DJ

Have you looked into any of the battery retailers? You should checkout BatteriesPlus If they don't have what you need in stock, they can usually find it for you.