Why not engineer inefficiency?, aka "Forget to charge my battery and take me to Jabba now" the iBot said

by Michael S. Kaplan, published on 2010/10/23 06:01 -04:00, original URI: http://blogs.msdn.com/b/michkap/archive/2010/10/23/10079839.aspx

Anyway, I have been going on for a while about our awesome health care plan and how unhappy I was at what I believe to be issues behind pending changes.

I have also leveled specific charges at what I believe are mostly administrative sloppiness issues that cost Microsoft money and which if they were doing right they'd have fewer problems now.

The scooters I used to use all the time made use of batteries. And so does the iBot I use now.

You may know or possibly have heard the expression "it's not the initial investment, it's the upkeep."

This rather amazing chair uses Nickel-Cadmium (a.k.a. Ni-Cd, a.k.a. Ni-Cad) batteries. This is nit entirely unusual in wheelchairs.

On the whole I wouldn't care about whether they were Ni-Cad or the Lithium Ion batteries I use in my laptops, except for the known memory effects that Ni-Cad batteries can suffer from.

It is more complicated than I'll present here, but this is not a Battery Blog so I feel comfortable with the simplification.

In essence, if you set the battery up to recharge every day and it never gets below a certain percentage, then it will tend to forget its own lower limit and start thinking the lowest level it has reached is the lower limit.

The imagine it conjures in my mind is that weak-minded assistant to Jabba the Hutt who Luke Skywalker was able to adle so easily. Luke confused Bib Fortuna and filled the vacuum created with new instructions.

And NiCad batteries seem to be just as easy to confuse, though it does take a bit longer.

1) You can fully use up the charge every day park it at virtually 0% and charge it up fresh, so it will always think the full charge is nothing short of the full charge. There are way too many reasons why this is impractical, not the least of which the notion of every day using the same amount of the battery is more or less impossible to orchestrate.

2) You can periodically do a "deep discharge" by draining the battery all the way down and letting it charge back up.

The official recommendation for #2 is monthly, but I have found this to be less than ideal, and tend to do it at least weekly (and more often any time the battery ends it's day under 15%.

Officially they rate the battery as lasting for a year, though through a practice of doing it once a month for the first half of the battery's life and with my new schedule for the second half, I have made it last two years.

This next time I will use my way from the start an I hope to make it last longer. I'm off to as good start so far, we'll see what happens.

When it was time to get the battery replaced, I had to put up the money myself and tehy billed the insurance (check to me afterward since I paid upfront).

Eventually I got the Explanation of Benefits (EOB). It was attached to a check for $24.09.

Of course, I call the insurance company. They inform me that this the "reasonable and customary amount" given the code it was billed with. "Perhaps they mis-coded it?" was the question presented to me.

The woman working for Blue Cross explained the procedure for them to change the claim.

They are frustrated, not with me but with the fact that they do not feel there is a better code.

"What is the code?" I ask. Though she doesn't tell me. She suggests it is the insurance company's issue.

I call the insurance company again, and after a bit of time re-iterating that this is the usual amount, I am given the code being sent to them.

The text description for this code is "Wheelchair component or accessory, not otherwise specified"

Well crap, no wonder they paid so little. This looks like the code you would use for replacing the cup holder (if it had a cup holder, which it doesn't). Clearly this does look wrong.

I resolve to call the iBot reimbursement folks again, but first I prepare myself. It looks like perhaps another code would be more appropriate, but I should try to figure out which one.

The description for that one is "Power wheelchair accessory, 12 to 24 amp hour sealed lead acid battery, each (e.g., gel cell, absorbed glassmat)".

Not much better, but a friend of mine in the industry tells me that the intent of the "e.g., gel cell" which is not about lead acid batteries, indicates it is more general purpose than it sounds.

I have looked through all the other "2008 HCPCS K-codes" and none of them come any closer.

I agree, but at least it hints at it being a battery, instead of the code more suited for the cigarette lighter (if the iBot had a cigarette lighter, which it does not).

Though the "reasonable and customary amount" for 2008 HCPCS K0733 is about the same as for the 2008 HCPCS K0108 anyway, so the insurance answer will likely be the same.

Other codes, like 2008 HCPCS E2397 ("Power wheelchair accessory, lithium-based battery, each") are closer to the mark, but the wrong battery type. In theory that could be considered fraud, and I do not question their unwillingness to go down that road. Even nearby codes like 2008 HCPCS E2399 ("Power wheelchair accessory, not otherwise classified interface, including all related electronics and any type mounting hardware") seem fraught with that sort of peril.

Companies that do not deal with insurance are often loathe to test the limits, and at no point did either they oir the insurance company deign to speak directly, as that would have made entirely too much sense.

She suggests that short of her hearing otherwise from her superiors, the only way to handle this, especially when Blue Cross originally claimed to expect that the battery to be covered, was to appeal the decision.

Of course I am on my own doing the appeal, though I am forwarded the iBot battery stats to help me do it.

I am reminded of something I was told by several people in response to my previous insurance posts: that the principal cost for the typical person is the administrative overhead. And I can't help feeling like this is engineered overhead:

This problem of mine would ordinarily be expected to occur at least five times and perhaps 10 times or more. Yet the insurance has no methodology by which to bill for such a situation that does not rely on the time consuming for me and more expensive for the insurance company (under the "time is money" theory of resource costs) process of the appeal?

I guess maybe if I were too dumb or too busy to or whatever to appeal than the insurance company saves some money. Or Microsoft saves some money.

But Microsoft will never see this one (people reading my blog notwithstanding), as Blue Cross will pay the amount on first appeal anyway.

This is hardly unique to my iBot -- a casual survey of just about every powered wheelchair and scooter will show that irregardless of battery type batteries will usually and customarily cost way more than the "reasonable and customary amount" and that the effective life of batteries is pretty much universally less than the devices they power.

So in other words this whole situation is engineered wrong, and someone should fix it, to minimize the additional costs, costs that while not the biggest part of the expense in my case can well be in other cases. More common cases.

I plan to make this battery last as long as I can. The fewer the number of times I have to deal with this crap the better. Maybe that is everyone's intent here in making it such a pain in the ass?

1) The expected charge/discharge cycle if NiCad batteries is supposedly about 800 - 1000 as claimed by vendors. You've had your iBot for two years and regularly discharge the batteries to 15%. So I'd say you're near the end of the life cycle of those batteries.

2) The memory effect in NiCad batteries may be an urban myth and may have started with some satellites who were in the earths shadow a fixed period of time almost all the time.

3) NiCad batteries are much better suited for outdoor use as they don't lose as much capacity when it gets colder outside compared to other technologies such as lithium ion. And they're cheaper which I'm sure is a factor.

The NiCad memory effect is documented at batteryuniversity.com/.../memory_myth_or_fact. Basically the surface of the electrodes grows larger crystals than usual, and those crystals prevent the electrolyte from making best contact with the active electrode material, hence lower capacity.

I drive a Prius, which has a NiMH battery. To get best life out of it, the car doesn't use the full range of charge, charging only to about 80% and discharging to 40%. (These are the limits of the displayed state of charge meter: the car actually tries to stay at 75% of the displayed range - 70% real SoC - and will aggressively use charge over that, and won't let you stay in forced-EV mode with less than 25% displayed - 50% real SoC.) Many shallow cycles are actually better for the battery than a smaller number of deep cycles. First-generation cars are starting to need new batteries, but only after 7-8 years and usually over 100,000 miles.

Most laptops and other consumer electronic gear use the full range of the battery and typically have poor charge algorithms that kill the battery within a short period. (For example, most 'desktop replacement' laptops are nearly always on mains power, the laptop applies a constant trickle charge, and this constant trickle damages the cells.) I'd hope your IBOT doesn't do the same.

I'm surprised that, given the known poisonous effects of cadmium and various jurisdictions' efforts to remove it from manufacturing entirely, they didn't instead choose NiMH, which are generally lighter than NiCad for the same capacity and don't suffer so heavily from memory effects. They may have fallen foul of Chevron's ownership of patents on large-format NiMH batteries, with a capacity of 7.2Ah and nominal 67.2V. Developed partly by GM, for the EV1 electric car, sold to Texaco when the EV1s were crushed. It's a common theme on Prius user groups that 'Chevron prevents NiMH-based electric cars', though it's not totally clear exactly which patents are involved and why they can't be circumvented. Chevron have sold Cobasys to SB LiMotive (Samsung and Bosch joint venture for automotive lithium-ion batteries) but didn't re-assign all their battery patents.

Different chemistries are better for different situations. NiCads are considered to be more rugged and last for more cycles than NiMH, and have lower self-discharge rates. However, your IBOT is in daily use, and no doubt you recharge it at whatever opportunities are available. The shallower-cycle would likely have compensated for the NiMH drawbacks, in my view.