24/7 Notebook Power? 60
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?"
Oh yeah (Score:1, Funny)
And here we see the state of health care. You've got enough cash to buy eight laptops, wireless cards, wireless infrastructure, and server software for whatever meaningless task you're doing with them (quake), but you're too cheap to buy batteries.
Tell us what hospital, so I can make sure if I get sick I don't go there. Do you re-use needles too?
Re:Oh yeah (Score:4, Insightful)
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.
Re:Oh yeah (Score:1)
Re:Oh yeah (Score:2)
Second, most links are placed on the roof. Most people wanting to take a phone call do so inside the hopital, close to machines which can be affected by it.
And when it comes to hospitals I'd rather you don't take any chances as far as interference is concerned.
Wireless Electricity (Score:1)
However, with the present efficiency of the technology, you'd have to beam kilowatts of microwaves down the hallway in order to get enough power for laptops in the hallway. (For comparison: a microwave oven uses about a kilowatt)
Or you could use Tesla's electromagnetic pulse system, but you'll have to make a building without a metal frame...and have clients park miles away or the parking lot will be full of sparks.
Re:Oh yeah (Score:1)
I agree, just buy 6 laptops and a bunch of spare batteries.
Some ideas (Score:2)
Having a bank of spare batteries charging off of a solar array would also be an interesting alternative.
Some reality (Score:2)
On top of that, the laptop is already set up to accept DC input. Carrying an inverter on the cart to run the AC power supply just adds two redundant conversion steps and their losses, plus the capital cost of the inverter and its wiring plus the downtime from the inevitable failures. You must have some critical thinking skills somewhere; try using them.
The author said: Your reading skills need a tune-up also.Re:Some reality (Score:2, Interesting)
Re:Some ideas (Score:1)
Re:Some ideas (Score:1)
Motorcycle batteries (Score:5, Informative)
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!
Wrong battery type, missing information (Score:5, Informative)
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.
Re:Wrong battery type, missing information (Score:2, Interesting)
What this guy should really be doing is not considering laptops in the first place, but using something like simple, liquid-proof, touchscreen "webpad" terminals (wireless if the hospital allows.) Like the ones used by waiters.
You don't need all the extra junk in a laptop to perform data entry. Not to mention the maintenance headaches, and the practical impossibility of what he wants to do, short of cold fusion. Wouldn't everybody like to have our laptops running 24/7 without ever needing to recharge the batteries?
Laptops are almost ridiculously not suited to this application. To me it sounds like the guy just got his hands on a technology budget for the first time and is itching to spend it. If he's budgeted enough money for a bunch of wireless laptops but not enough to keep the batteries charged (is that really such a huge expense?) something is wrong with the whole picture.
Or maybe the original post was a joke and I didn't get it.
Re:Wrong battery type, missing information (Score:2)
As others have stated... (Score:2, Informative)
Don't go for a standard automotive battery, as they're not designed to be drained right down and charged up, a Deep Cell is.
I can't think of any other solutions that would provide power for a lengthy time without being attached to a cord, beyond a generator of some sort... and I don't know of any that would produce enough power to run a lap top while at the same time provide disadvantages that one could not have in a setting that you're talking about.
A car batter in't that heavey, particuarly on a cart... problem is of course, changeing them when they're dischrged
Re:As others have stated... (Score:2)
Scrap the inverter and go with a straight deep cycle and something to possibly step down or up the voltage to whatever level it needs. The laptop should take striahgt DC, and it would allow you better usage of your batteries juice.
Re:As others have stated... (Score:2)
Now comes the "difficult" outside-the-box thinking; It's all about logistics right? So, why not junk any carts that would be difficult for the nurses to wheel around (assuming a load of 30-40 pounds) and get carts that are easy for them to wheel around.
I've wheeled tons of equipment on carts, and I can say that without a doubt it is the quality of the cart and its appropriateness for the task that is more important than the weight. Shitty carts make wheeling around a 20 pound projector and VCR a pain in the ass, and a good cart makes wheeling around 100+ pound loads much easier than you would think!
Factors to consider when buying carts:
Re:As others have stated... (Score:2)
If you prefer simplicity and hardware hacking doesn't bother you, run may laptop directly from a 12 volt battery.
Every laptop I have seen have fully functional built in inverters that regulate the voltage, while asking for 15 - 19 volts. If the input voltage drops, it will draw more current. It seems like this supply would make an external regulated supply redundant and just another point of failure. I have been running my laptops on the go this way for years.
A fuse is necessary. If the input supply is reversed, a diode will clamp the supply expecting a fuse to release the circuit. Most supplies are designed correctly and have a SCR crowbar circuit that will clamp the entire supply to ground if an overvoltage condition exists. These circuits protect the laptop when things go wrong and the fuse is necessary for them to operate, else you might have a fire.
Re:As others have stated... (Score:1)
I love this - do you work in PR?
Re:As others have stated... (Score:2)
Re:As others have stated... (Score:1)
I agree, except oftentimes the input voltage on laptops exceeds 12VDC. I think my Sony is 19.5V or something. Other laptop brands have dedicated "Car" adapters that can be purchased separately. I couldn't find on for my piece of shite. Actually, it isn't that bad, the screen is nice.
Buy laptops that have available 12V adapters, then use gel-cell or other deep cycle battery solution that meets the amp hour needs.
PS - 50 amp hours will give you 50 amps in an hour, essentially. Actually, the AH rating is averaged over a 20 hour cycle I think.
Chris
wtf? (Score:4, Funny)
Your best option. (Score:5, Insightful)
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.
Re:Your best option. (Score:1)
Re:Your best option. (Score:2)
It is only here in parts, hell they have not even figured it all out yet.
Have you seen the documentation on HIPPA? No you have only seen what has been given to you.
Trust in that HIPPA is no where near done with your, me, or everyone else.
I don't even think HIPPA knows when they will be done declaring what are really going to do.
Microwave (Score:3, Funny)
Re:Microwave (Score:3, Funny)
Re:Microwave (Score:1)
Reconsider the car battery (Score:4, Informative)
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.
What is this for? (Score:2, Insightful)
You might want to reconsider the type of hardware you're going to be using if you can fit it in. A few Palm handhelds, bluetooth addons, and creative programming could get you the uptime and functionality you need from these things.
heat? (Score:1)
- the portable runs out of power
- it melts (or sets something on fire)
Car/Plane adapters and deep-cycle batteries (Score:5, Informative)
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 $6-800 for a replacement 2GB hard drive, and can do it because that particular piece of medical equipment is certified only with that no-longer-available-new component and they prepurchased them knowing they'd need them as replacement components. The medical equipment world is a whole different place.
get external chargers (Score:3, Insightful)
A simple choice would be Mac iBooks: they are reasonably cheap, allow on-the-fly battery changes, and have decent battery life.
With the dual battery option, you could have a custom desktop accessory to warn you when one battery is empty, giving you still a few more hours of usage out of the other.
Re:get external chargers (Score:1)
The same would apply to Dell laptop such as the Inspiron series with a modular bay
and a battery bay in the front. The modular bay can also hold a battery. With a 4-hour
recharge cycle, you could maintain a single laptop with only two batteries. On long flights,
I get about 10 hours up-time on my Inspiron 8000 with batteries in both slots. Mind you,
this is with the energy-saving mode turned on and little DVD-R drive use. I don't know
how the batteries would hold up using a wireless card.
Dell claims that the Inspiron 8200 has a battery life of 2-3 hours and a recharge time of
one hour with the battery off. That has not been my experience with the 8000 model.
Maybe it lives longer under Linux...
The whole proposal, on the other hand, seems to involve quite a bit of work and breakage
risk. Plus, things get stolen in hospitals. It seems like a handheld wireless solution might
be better (as suggested in other posts).
ElectroVaya Powerpad may help (Score:3, Informative)
But at 500$ for it, it may be out of your budget.
Re:ElectroVaya Powerpad may help (Score:1)
Extra AC Adapters? (Score:2, Informative)
Then, in each patient room, there was an AC adapter that was always plugged into the wall. Whenever a doctor/nurse/etc would be in the room for anything longer than 'please wait here', they would sit down to talk with the patient and plug the subnotebook into the AC adapter. Something like this, in addition to some of the other suggestions given (like hot-swappable batteries), might work for you.
Do what malls do with golf carts (Score:3, Insightful)
Do the same thing malls have done for years with security golf carts: buy twice as many laptops as you need, and rotate them out of duty every 12 hours (or less). That way, the equipment isn't under constant wear, plus you have spares for emergency repairs, and you can do maintenance. (How else do you plan on applying patches and upgrades when you only have exactly enough to keep in constant use?) Unfortunately, charging and replacing lithium-ion batteries is expensive, and cost is definitely an issue.
Ask your supervisors if they would only keep on hand exactly the number of scalpels they think they would need - or if they would have enough to clean them and repair them, and not have to worry about surgeons running from OR to OR looking for a spare scalpel.
You can't use a car battery (Score:1)
The next problem is that having an inverter plugged to a car battery to power a notebook will work...but for a few hours until the car battery is drained anyway. Ever leave your headlights on overnight and forgot to turn them off in the morning...result?...a car that won't start because the battery is dead. Your lowbeams use ~55 watts each...110 watts total...your notebooks prolly use around 80 watts or so...so after several hours it will drain the car battery.
If you decide to use car batteries...I don't think that is safe. What happens if it falls off the car t and cracks open and leaks? The Acid in the battery will eat through just about anything.
Car batteries weigh alot. Like 50 pounds...Yeah they will be on carts, but 50 lbs on a cart is still heavy to push when you have a 25 year old 100 lb nurse or a 65 year old grandma nurse pushing it.
Car battiers are expensive...$60 a pop to replace them every several hours.
Good luck with your project!
Battery Leakage (Score:1)
These guys [optimabatteries.com] make batteries that don't leak gas.
But, the idea of car batteries flying around a hospital doesn't sit quite well with me.
There's no way to save money here (Score:3, Informative)
resources (Score:2, Interesting)
http://www.uuhome.de/william.darden/dcfaq.htm [uuhome.de]
also one almost identical for car/motorcycle batteries
http://www.uuhome.de/william.darden/carfaq.htm [uuhome.de]
these references will be all you will ever need to know about charging/discharging times, how many cycles to expect and to what extent you can discharge the batteries and still retain a viable performance.
pay specific attention to
#12 (in the DC or 16 in the car faq) HOW CAN I REVIVE A SULFATED BATTERY?
for help in keeping costs down, it contains specific information to revive the battery by "cleansing it" and replacing electrolyte.
Good luck!
--Meat
What? No fuel cell posts? (Score:2)
As a health care facilty, I would expect you'd have easier access to suppliers of compressed gas (i.e. hydrogen) than others.
Have the people in charge (Score:2, Informative)
Re:Have the people in charge (Score:2)
Medical devices are tested under such rigid standards that low power radio waves are not much of a risk. I was at a emergency recently and they used cordless phones and other radio devices.
batteries (Score:2, Interesting)
;^)
Put a sealed glassmat agm battery on the bottom level of the cart. cheaper just use a gelcel. A cheap sealed 12 volt gelcell will cost about what a tiny new laptop battery goes for, hold like 50 times the amp hours in it, something like that anyway, a lot. Use carts with larger wheels if pushing is a problem. Stuff rolls easy if the wheels are cool, don't be cheap there. Any normal human can roll around several hundred lbs no sweat if the casters are decent. Small wheels ="bad", larger diameter wheels ="good", easier to roll. Even a 4 foot 6 nurse can still push the cart. Don't let thembuffalo you with "they can't do it". That is BS. Even a 50 lb batt on a cart is doable. Even with all their other gear. One of those batts will run a laptop for a LONG time, I know I can run one of my old powerbooks for more than 24 hours without completely discharging a normal 12volt semi deep discharge battery. Piece of cake really. Look at laptop batteries, weigh zip, look at an industrial deep discharge battery-massive. Plenty-o-juice. In fact, when you go to work, take a peek at the batteries the maintenance guys use in their electric floor scrubbers (if they are cordless) I bet you use in the hospital. Those will be industrial "traction" batteries designed for heavy extended use, and chances are they will be either crown brand or rolls/surrette. You'll be getting something very similar, in fact, the exact identical (if 12 volt) batteries in those floor polishers will probably work for you exactly as you need, simplifing supply and inventory and re-charging. Go ahead, go look at them.
Want to go a few more bucks, use two 6 volt agm batts wired in series for 12 volt, then use that input for the laptops.
BTW, use laptops that will TAKE 12 volts natively, or suffer a small loss with the car adapter/inverters. Not much, but some.
At your recharge station use a solar/alternate energy industry controlled 3 stage charger adjusted for the type of batt you get, don't use a one stage car battery charger, they are the worst way to charge batteries you can buy, and most of them don't even charge glass mat or gelled sealed batteries without 'sploding them. they are "adequate'for recharging your starter battery, and that's about it. Mostly they suck. heh.
Good rule of thumb for batt longevity is try not to deep discharge them, the closer to "full" you can keep them the better. Me, personally try to never drop below 80% or so charged, even though I have gone lower very occassionally. for your uses even 60% full is still quite doable and the batts should last for years. You should have zip problems with your batts running one laptop for an an entire shift. You will need extra carts and batts though, as recharge time can be long, just depends is all.
There also exists a device called a "desulphator", several brands out there now, they hook to the batteries and oscillate the sulphates from the acid electrolyte right back off the plates, and work VERY well. I recommend them to anyone who wants mileage out of their batteries.
There are other more exotic batteries on the market now, and even some fuel cells coming, but geez loeez they are 'spensive.
The batteries themselves can fit into nice neat plastic vented battery boxes from walmart, like 10$ apiece. Cabling for adding a female receptacle for the laptops male DC 12 volt plug you can do yourself, you're a tech, right? Female 12 volt (car-type) receptacles are on the counter at any auto parts store, 4$, 8$ for dual or triple.
I think you need a PDA? (Score:2)
I think you need a PDA, not a laptop. Not knowing your application I can't really say more, butif they can't push a big battery (not to mention the health risks of having one in a hospital) then they need something lighter. A PDA with an application to hold whatever data, and hot sycn it to the terminal at the nurse's station. PDAs can go weeks on a set of cheap batteries, and they are small enough that the nurse won't want to go back to a lighter clipboard.
Hmmm.... (Score:2)
Given enough $$$'s anything is possible... (Score:1)