EBME Forums Forums Maintenance Spare Parts Battery Blues

For those of you who read my posting about repacking GE DASH monitor Lithium Ion batteries, well it has been a waste of time so far. It would appear that the inbuild battery circuitry can detect and store a decrease in capacity, but not an increase. So I cannot go from 40% back to 100%. At least, not with the rejuvenator I have here in my workshop. I am aware that some circuits can be reset, but the batteries I have here contain Maxim IC's for which I cannot find the relevent data. So its new batteries unfortunately. But not from GE. We have found another source at half their price!

So it's good news and bad news, then.

But ... regarding the Maxim chips:- no clues emanating from the links provided by Tony Royston at the second page of this thread?

Sort of. If the replacement batterys were more expensive I would be tempted to give the PC link circuit thingie a go. But since the difference is not great, I shall stick with replacements rather than getting the old ones repacked.

State of Charge, Coulomb Counting ... and all the rest (who said it wasn't fun)? The web is full of this stuff if anyone has the time to research it! But I must report that my own somewhat brief foray did not unearth any mention of that most important "spec":- that of £ per Ah.

Notice that the first link mentions the Kalman Filter*.

The second link lays out the case for precise battery monitoring in personal hand-held communications devices. Fair enough. But (as I keep saying) why are we being lumbered with such complexity (and resultant expense) in medical equipment such as patient monitors?

The third link discusses some of the finer points to be borne in mind when charging Li-Ion batteries.


* Which addresses the age-old question:- how do you get accurate information out of inaccurate data?

Have just fitted the new battery. Upon inspection of the old one, it may be interesting to note that the monitoring circuitry (which is relatively complex ... including what looks like a Maxim 1414) is contained (in a nice little plastic box) within the battery pack itself. Again, to my mind it all seems so unnecessary ... especially as the manufacturer recommends that these batteries be replaced annually!

Dont know if you have got this confused but the 7100's are not a smart battery and they last for ages.

Which battery, Billy? The 14.8 V 3800 mAh Li-ion? P/N T4UR18650F-2-4644*. Completely dead. The manual says one year, or 300 charge-discharge cycles.

It might not appear to be a "smart" type as you can simply exchange it (without any "cal" procedure, etc.), but the battery pack does contain all the gubbins I've mentioned. Plug 'n' Play?

* Although the manual says ...4664, which is useful. Fukuda Denshi UK use P/N T4UR18650F (which is fair enough).

Do the batteries really need changing after 1 year. It seems to be a very short life for a battery.
Those who use nitric oxide will know of the cell with a built in timer for obsolescence which you must change yearly even though the thing seems to be working correctly.

Has anyone seen the latest thing from Draeger where the consumables on their anaesthetic machines are chipped so they have to be changed at the correct interval and I presume you cannot get copy parts. It ensures patient safety by correct operation of the equipment....oh and sales as well.

Adding intelligence to things does seem to have a down side.
Or an up side depends on whether you are buying or selling.

Yours, as cynical as ever

Robert

Then, next thing you know, they announce that such-and-such bit of kit shall "no longer be supported" from such-and-such a date.

All this only serves to remind us (me, whomever) that we have to keep on, er, fighting!

In reality it has nothing to do with patient safety. That's just the "frightener". But everything to do with revenue streams ... and gouging!

You got there eventually Geoff. It's all about the gouge!!!