24/7 Notebook Power?

RobPiano asks: "Help! I am working at a health care facility that may be expanding its network to have eight Fujitsu wireless notebooks. These notebooks would be required to run nearly 24/7 with minimum downtime. Unfortunately, charging and replacing lithium-ion batteries is expensive, and cost is definitely an issue. The notebooks are placed on carts, so an 'on-cart power supply' is an option, but having it plugged in is not. I considered a car battery, but most of the nurses would have trouble pushing both cart and battery. How have you readers kept your systems powered?"

Comments

Motorcycle batteries

[0x20]

How about motorcycle batteries? They're smaller and lighter than car batteries, and many can probably produce the output you need.

Of course you'd need to buy a bunch of trickle chargers (for plugging in an night.) They can be expensive. If you have any electrical knowledge you could probably build them yourself on the cheap.

You could also get really creative and put some little bicycle generators (the friction kind) on the cart wheels to run some extra power into the batteries during the rounds.

Whatever you do, if it involves lead-acid batteries and a health-care facility, make sure to run the plans by someone with some electrical knowhow to make sure you won't overcharge the batteries and risk spilling or spraying acid all over the place. And keep them in sealed containers in case you do!

wtf?

[Anonymous Coward]

ok, let me get this straight. You want an effectively UNLIMITED powersupply (24/7) and you can't ever plug it in, AND "cost is an issue". In otherwords, you want free unlimited energy in portable form. Hmm. Maybe I could interest you in this "cold fusion" device or this perpetual motion machine.

Your best option.

[Neck_of_the_Woods]

Having worked in a hospital setting and knowning what problem you about to have the battery life of you laptop is going to be the smallest problem with what you are about to try to do.

Anyway, problem at hand. I know how hospitals are about money, your not solving a problem you are the problem. Damn money pit that IT group is but you going to have to ask for more money and I will supply why.

#1. You can't do the "recarge" batterys and replace them schtick because laptops are frail little things and you know they will break with repeated switching of batteries within the month. Look who your going to be giving them to and really ask your self this question. Will they break them and how fast. Yep, your going to need backup systems, and at least 3 of them at any given time.

#2. My guess is your best bet is going to be to get some kind of tablet computer "Mira" would be and example. Or a small CE device, something that has low power consumption that will last at least 4 hours. That is a basic shift. What ever software your trying to run get it for Citrix and ICA client them in over a wireless backbone. Remember that HIPPA is coming soon, your going to need to get the specs on your wireless, encyrption, etc..don't get left holding the bag on the HIPPA restrictions. Bring them up now!
We did a wireless CE to citrix solution using arrowpoint switches. These handhelds had light pens to scan the patients to pull med records. Again I stress security, wireless--medical records...you see my point about your battery life not being your only concern.

I wish you the best of luck, Doctors and computers are about the hardest thing in the world to get to work together. If you say it is for the nurse, well then it is for the doctor. Believe it. Anyway, good luck.

Reconsider the car battery

[RackinFrackin]

I considered a car battery, but most of the nurses would have trouble pushing both cart and battery.

Is the weight of a car battery really an issue? Sure they are heavy, but they are a lot lighter than a patient in a wheelchair, or one of those roll-around stretchers - both of which are routinely moved by nurses.

Placing a large battery on the bottom of the cart would also give it a low center of gravity increase its stability.

Re:Oh yeah

[druzicka]

I have to agree... This smacks of a poorly designed solution. We're missing a big piece of the puzzle: What application is being deployed. Instead of presenting the solution and asking how to do something impossible (keep a laptop battery permanently charged and mobile without plugging it into a AC wall socket) it would have been better to explain what application they're trying to use. Here are some questions that I would ask:

1) Are roving notebook PCs really the best option? I don't see why a stationary terminal couldn't accomplish the same task.
2)Does the vendor of this application recommend wireless LAN in a hospital setting? (AFAIK, cell phones and two-way pagers have to be turned off in a hospital because the transmitters in those devices can interfere with medical equipment.)
3) What kind of application requires that the client be permanently available? If data storage or network resources need to be retreived from the client, shouldn't they be stored on a central server rather than a bunch of roving laptops?

I suspect that the roving laptop solution was selected based on cost. The biggest obstacle that I see when designing a IT solution to a particular problem is budgeting. The fact of the matter is that if the money available for a solution will only allow you to implement a half-assed solution, then the project shouldn't be done. If financial contraints prevent the job from being done right, don't waste that money on the project. Instead push back for more funds, and if they aren't available, wait unit the next budget cycle. Truly, if the project is so necessary that it can't wait for another budget, then the project will have to be a priority and funds will have to be allocated from the current resources.

Car/Plane adapters and deep-cycle batteries

[Fencepost]

For a lot of notebooks you can now get DC adapters that let you use them with external power in a car or in business class on many of the US airlines. These are DC-DC converters, which avoids the problem of power loss in an inverter.

For deep-cycle batteries, you should be able to find fairly small ones, but do the math to figure out how much capacity you need to be able to run for multiple days.

Someone else mentioned using CE devices or something similar - that's actually a very good plan depending on what use these will be seeing.

Keep in mind as well that you're entering a world of regulatory hell if these things are going to be anywhere near patients. If it's close to a patient, it's not a computer - it's a piece of medical equipment no matter how much you might think it looks like a computer. You can debate that, but be sure you talk to your legal folks first because you'll lose your shorts when someone dies while there was non-certified medical equipment around.

Side note: I've talked to folks who charge $6-800 for a replacement 2GB hard drive, and can do it because that particular piece of medical equipment is certified only with that no-longer-available-new component and they prepurchased them knowing they'd need them as replacement components. The medical equipment world is a whole different place.

Wrong battery type, missing information

[Spamalamadingdong]

A motorcycle starting battery is almost certainly not suitable for this job. Starting batteries are meant to power a starter motor for a few seconds, discharging them a few percent. Then they are recharged almost immediately. Using them otherwise is a sure bet for rapid capacity loss and early failure.

This application is totally different. The laptop and battery would be in use for at least the duration of a shift, possibly all day. This calls for a deep-cycle battery which can be drained to a large fraction of its capacity on every cycle without taking damage. Something in the form factor of a motorcycle battery might do the trick, but you wouldn't want the real thing.

The article is missing information on the actual power drain of the laptops and the required period of operation before recharges. If we can assume that the laptop draws 30 watts and it needs to run for a 10-hour shift, that's 300 watt-hours. If you could get a 50 amp-hour deep-cycle battery, it would only go to 60% depth of discharge on that cycle. Such a battery would probably weigh about 30-35 pounds; an absorbed glass mat design has no free liquid electrolyte and would probably meet the hospital's safety requirements. If you need more capacity or less weight you are probably talking NiMH batteries and your cost/WH goes way up.

Another thing that's missing is whether the batteries must be mounted to the equipment (is there a risk of them being stolen?) or if they can be made swappable. It would be much easier to have a battery in a little carrier that slips into the cart and plugs in than to have it mounted to the cart; being able to hot-swap batteries would make it very easy to have a set in use and another set charging at all times. This is a lot better than having to park the cart and plug it in for the duration of the charging cycle when the nurse needs to be on the floor.

Finally, you're going to have some issues with regard to tracking of the battery cycling and lifespan. A solution to that involving something like Dallas Semi iButtons could easily cost ten times as much to engineer and roll out as all the batteries in your hospital. If you do it on paper or by ear, you're going to be caught by surprise by flaky units or systematic problems with over-discharged batteries (which can hammer you with costs at very inconvenient times). Tracking batteries, their charging and discharging behavior and other vital stats with paper is just too error-prone and labor-intensive to work well. This guy's going to need all his smarts to make this work, no doubt about it.