New instrument won't start.
 

My 3.5 month old Akai wind synth refused to start yesterday. The symptoms seem to be related to battery charging. I have emailed the vendor for advice. :sad:

My low-cost kindle keeps showing the "charge me" logo but the logo is still thre after many hours of recharrge... And the orange light becomes greeen for only 3 seconds befor turning out.

Did I lose it?

[QUOTE=ET_;406950]My low-cost kindle keeps showing the "charge me" logo but the logo is still thre after many hours of recharrge... And the orange light becomes greeen for only 3 seconds befor turning out.

Did I lose it?[/QUOTE]
They can get into a state where they won't charge. Which kindle is it. Did you try a reset yet?[url]http://m.wikihow.com/Reset-a-Kindle[/url]

I your case with a deeply discharged battery, I worry about the battery might not take a charge now but I would still plug it in and try to do a reset while it is plugged in. If it successfully boots up and goes through a visible software resetting process, leave it plugged in an see if it then charges.

Also, I have returned two kindles to Amazon. Their customer service was pretty good at least for me.

[QUOTE=only_human;406951]They can get into a state where they won't charge. Which kindle is it. Did you try a reset yet?[url]http://m.wikihow.com/Reset-a-Kindle[/url]

I your case with a deeply discharged battery, I worry about the battery might not take a charge now but I would still plug it in and try to do a reset while it is plugged in. If it successfully boots up and goes through a visible software resetting process, leave it plugged in an see if it then charges.

Also, I have returned two kindles to Amazon. Their customer service was pretty good at least for me.[/QUOTE]

It worked like a charm! :-D Thank you! :smile: :tu:

[QUOTE=kladner;406641]My 3.5 month old Akai wind synth refused to start yesterday. The symptoms seem to be related to battery charging. I have emailed the vendor for advice. :sad:[/QUOTE]

Between the vendor's forum and Akai's I found my situation described pretty clearly. The problem seems to be that in some circumstances the instrument lets the battery go into deep discharge. Lithium ion batteries don't like this and stop taking a charge. The cure turns out to be "zapping" the battery with jolts of higher voltage. A DVM said it was only at 3.2 v, instead of the rated 3.7 v. Using a "dumb" power supply, (ancient Radio Shack multi-voltage wall wart), I started giving it shots of a nominal 4.5 v. I started with 10 seconds, and worked up to 30 seconds, taking readings on the battery in between. When I got it up to the recommended 3.5 v, I put it back in the instrument, plugged it in, and it started charging.

It will take some use to see if it holds a charge. It only goes to about 96% charge, while I think it used to go to 99%. If it lacks endurance, I will try a couple more "zaps" and see if that brings it up. It has been a rather nervous procedure, but Akai has yet to answer my email, and I did not really want to send the whole instrument away for who-knows-how-long, on account of a balky battery. Also, if the procedure had not worked, I would still have warrantee to fall back on as there is no obvious evidence that I had been mucking around with it.

EDIT: I was familiar with this approach as a means of reviving NiCd batteries which had gotten stuck in a shallow charge cycle. Also, there were reports of success in the forum. Still, it was a great relief to see signs of charging.

[QUOTE=kladner;406972]A DVM said it was only at 3.2 v, instead of the rated 3.7 v.[/QUOTE]3.2v is not deep discharge for Li-ion chemistries. I always take my bike batteries down to 2.8v/cell without any issues. I suspect the real problem is the badly performing charger in the device. And your "zapping" was really just bringing in some charge to raise the voltage to a level the inbuilt charger could work from.

TL;DR - Use a better charger.

[QUOTE=retina;406974]3.2v is not deep discharge for Li-ion chemistries. I always take by bike batteries down to 2.8v/cell without any issues. I suspect the real problem is the badly performing charger in the device. And your "zapping" was really just bringing in some charge to raise the voltage to a level the inbuilt charger could work from.

TL;DR - [B]Use a better charger.[/B][/QUOTE]

I wish it were that simple. Charging is via USB, either from a computer or a power supply. I think the problem is with some internal circuitry, possibly the tiny circuit board which others have shown to be strapped onto the battery. Only guessing here, but perhaps the charge sensing has too limited a range.

For all of the equipment I've ever seen the charge circuit is never strapped to the battery. There may be a small over-voltage/over-current/over-discharge/over-temperature protector board on the battery, that is normal. Usually the charger is a separate board. In theory you could remove that and replace it with a better charger. Perhaps the manufacturer has an upgrade kit or something?

[QUOTE=retina;406974]3.2v is not deep discharge for Li-ion chemistries. I always take my bike batteries down to 2.8v/cell without any issues. I suspect the real problem is the badly performing charger in the device. And your "zapping" was really just bringing in some charge to raise the voltage to a level the inbuilt charger could work from.

TL;DR - Use a better charger.[/QUOTE]

I may have misreported the low-end voltage. In any case, pushing a little current into the battery got it to start taking a charge again. (Remember that a USB connector is the only route for charging this thing.) Starting from a reported 96% charge level, I played it for an hour or so today, wireless, which cuts the charge life about in half, and it still said 96%. That is encouraging.

Someone else took the wrappings off one of these units. Photo attached.

[QUOTE=kladner;407521]Someone else took the wrappings off one of these units. Photo attached.[/QUOTE]To me that looks like a basic protector board. Temp/voltage/current trips. The charger board (which I suspect is not shown in the picture) would be where your problem lays.

Yes, that looks like a thermal+ fuse only. These batteries can give a very high current (like 20-30 amps!) for a short period of time, therefore an accidental short-circuit of the terminals will make the wires so hot, they can melt the plastic case (and physically go out through it) of flashlight/laptop/whatever casing you enclose them into. That little board will avoid giving ANY current if more than nominal (plus some percents) current is required from the battery, and it will avoid charging the battery with a wrong voltage; if you short the terminal wires, for example, nothing happens; also, when the temperature of it goes high, it works as a temporary switch, turning everything off for a time (or till cooled down). They are quite common, and we now require all our battery manufacturers to use them on all batteries we buy (we do not produce batteries in house). Especially after we had some "melting" accidents and even smoke, and our operators (worried for their health) refused to work with them anymore, the management went ballistic on this issue, and no battery is accepted in the factory if it does not have that small PCB attached. You know, when you tighten the screws in production you can clip a wire which is not perfectly aligned in the case and suddenly everything melts and starts smoking... Of course, nobody wants his own factory burned down.