Ya out there Red?

Yes, I would, because then I would research it. That answer is just a non-answer because YOU DON'T KNOW. If you show me, I will even publically admit that I am wrong, right here.

Jim

Which ones? What charging algorithim do they use? I would LOVE to use a better way.

Jim

It is really easy to check my claims. Just google "Lithium Polymer Charging Cycle". You will find nothing about any other type of charging method. With the pulse system, it is just basic math, (like the commas?)

1 amp for 100 ms is that same amount of power delivered as 100mA for the full second. It has been used by SLA chargers for years claiming some sort of cleansing of the plates. It is, however, an easy way to put energy into a battery and then let it sit while you measure the voltage of the cell instead of the voltage you are using to jam electrons into it. I wouldn't doubt that is exactly what the charger he keeps harping on is doing. Send a charge pulse, rest for XmS, read the pack voltage, average the value, repeat for as many cycles as needed. It is just CC/CV when the values are integrated.

Jim

| 1. Doug: cites specific evidence of non-constant current and | non-constant voltage regimes in at least one charger. Tends to bait | the person he's arguing with.

Just for the case of accuracy here, I've only posted once in this thread (well, this is post #2) so you don't really have enough information to come up with any sort of tendency, at least not in regards to this thread.

Perhaps you're attributing somebody else's posts to me?

I'm really more of a spectator in this thread, but since James Beck has pointed out that his designs are used in millions of chargers (?) out there, I think that's worth expanding on. If you think that's baiting him (or arguing with him), then so be it.

| Anyhow, carry on. I'll keep rubbernecking and feeling slightly | queasy from it...

Oh, it's too late for that now. You're now a part of the train wreck (as I would also appear to be) ...

NEVER said millions of charger. Better work on that reading comprehension. I said millions of PRODUCTS, big difference. Besides, that's still not the point. Let's assume that I know NOTHING about battery charges and you are going to enlighten me. Show me the datasheets that would substantiate your claims. My claims are easily googled. Jim

no he did not he said and I quote " "The funny thing is, he has probably been flying my products for years and doesn't even know it." how is that "millions of chargers" I for one have never flown a charger

If you think that's

Why? obviously at the end of the charge it puts out zero current! how else do you define 'end of charge'

I think you need a few lessons in logic first.

for the last.

You can argue all you like, but you assertion that that is the ONLY way things CAN happen according to thwe laws of physics, is the problem.

Its not the only way. You can have any V/i/t curve you want provided it doesn't violate the max current/max voltage limits of the cells by enough to damage them. There are an *infinite* number of curves that fit those boundary conditions.

In essence the problem resolves to fitting a piece of string in a box. As long as it doesn't go outside the box and goes from one corner to the other, it can take any path it wants.

Yes, I looked at the link and their charging pulses. It is CC/CV. It is PWM at the end. Once again, the pulses integrated over time make a CC/CV cycle. All you have to do is look at page 5 ov the manual and see.

Jim

crap statement as all charges do that that proves nothing

so you have failed where on the site does it state its a CC only charger then?????? and its not a pulsed cc start and pulsed cv finish as I said you cannot back up your claim one bit I can find hundreds of hits for CC/CV but not one for a CC only liPo charger as they don't exist as you cannot hit a charged cell at full current and it not go over voltage

and physics are different for you and Astro then

and thats bollocks you cannot have any curve you want and if you think you can you are utterly and totally, wrong the battery determines the curve not the charger show me any LiPo charge curve that does not have the voltage climbing and the current decreasing, or the current increasing and the voltage decreasing

another crap statement that has nothing to do with the thread I can walk three ways to my local shop so what?

but page 5 does not have any scales so it could be a pulsed voltage or a pulsed current which nether backs up his claim or disproves it

That's true. No X or Y legend. I just assumed......

I read the datasheet. I see no claim of a revolutionary new way to charge LiPo's or anything. The charge cycle is the same 'ol, same 'ol. Phase 1 (That somehow changes name to Mode 1 in the next paragraph) is just the standard preconditioning/cell guessing we talked about earlier in the thread. Mode 2 is just plain 'ol CC with a pause to more accurately measure the cell/pack voltage. Mode 3 is just a PWM taper to full charge. Which is just CV in pulsed form.

Nothing new and revolutionary here. I like how this is being heralded as the one big example of how we are wrong, and yet it is just the same 'ol crap as everyone else.

Jim

he cannot back up his claim but there are hundreds of sites to back up the CC/CV charge cycle, mind you do a google for "Astro 109" fires and see what this charger is capable of :-)

Not to deliberately throw my detracters a bone or anything, but there is one advantage to the pulsed charging method. You get more useable power from the battery. I know of some tests done with an ECar that had to use a PWM charger because a linear one would dissipate enough heat/power to damn near offset any savings from not burning gasoline. When they switched to a PWM charger the efficiency of the charger went WAYYYY up and one noted side effect was more useable power from the battery. I don't know why, I never followed up on it.

Jim

| > I'm really more of a spectator in this thread, but since James Beck | > has pointed out that his designs are used in millions of chargers (?) | > out there, I think that's worth expanding on. If you think that's | > baiting him (or arguing with him), then so be it. | | NEVER said millions of charger.

OK, you said millions of products. I did follow chargers with a (?) to indicate that I wasn't sure that they were chargers. I assume you're familiar with the convention of following something with a (?) to indicate that you're not certain of it?

| Better work on that reading comprehension.

Uh-huh.

| I said millions of PRODUCTS, big difference.

OK, then tell us about the products. Since they're apparantly relevant to the discussion, let's be specific about what they are.

| Besides, that's still not the point.

If you don't want to tell what your products are, that's fine too.

| Let's assume that I know NOTHING about battery charges and you are | going to enlighten me. Show me the datasheets that would | substantiate your claims.

I really haven't made any claims in this thread, except that chargers do exist that don't do CC/CV for LiPos. Perhaps you're thinking of somebody else's posts?

However, if you're looking for an example, you only need to look at any of the adapters that are put on a NiCd/NiMH charger to allow it to charge LiPo batteries.

Generally they just cut the circuit when it hits 4.2 volts/cell -- so the current is constant (during the entire charge period, anyways -- of course the current is zero before and after.) There is no CV phase at all.

Personally, I wouldn't bother with any of those adapters, but they do exist. Here's an example for you --

.

Of course, the downside is that your battery will not be completely charged. How close you get depends on your charge rate -- if it's high, your battery may be far from fully charged, and if it's low it will be close. But it's certainly possible to design a charger that gets your battery up to 99% charged using only a CC charge regime (you just charge at a low rate.)

Or you could design a charger that does multiple CC regimes (i.e. do

1C until voltage hits 4.2 volts, then 0.5C until voltage hits 4.2 volts, then 0.25C until voltage hits 4.2 volts, then 0.1C until it hits 4.2 volts again) then you could charge your battery almost completely and yet never have a true CV regime at all.

Or with a little smarts, your charger could calculate the internal resistance of the cell and actually charge up to higher than 4.2 volts (because the voltage would drop back to 4.2 volts once the current was off) but you'd better not make any mistakes or you'll damage the pack!

Or you could take your basic cell phone charger -- a 4.2 voltage source, run through a resistor to limit the current, into the battery. The only time the current or voltage (at the battery) is constant is at the end -- when current = 0 and voltage = 4.2 volts. (Though you might want to label that as a CV charger, as the input voltage (input to the resistor+battery, anyways) is a constant.)

Either way, I think CC/CV is so popular because 1) it works, and 2) it's easy to implement, especially to companies who have already made NiCd/NiMH chargers. But it's hardly the *only* possibility.

Why does it matter. That still doesn't change the thread.

Oh, I see you got a Popeil Pocket Hair Splitter for Christmas this year. Just because an adapter cuts out one portion of the charge cycle (the CV part) doesn't mean it isn't using the classic charge cycle, it is just deleting one part of it. Not much of a "charger" if the battery isn't charged.

Still, if you do the integration, you are just doing the CV portion by pulse width or cycle timing.

That's what is usually done in the deadtime. Still, old tech.

Still nothing new, see FLOAT CHARGER.

What other possibility? You said "hardly", so that must mean there are a myriad of choices. Throw a few at me. I read all the trade magazines, I see no big changes on the horizon. Battery Power Magazine, Electronic Products, Electronic Times, Electronics Component News (ECN), and the list goes on. Part of my job is to keep abreast of the situation. You going to be at the Battery Power Expo (Actually called Battery Power 2007) in Denver this spring? I am. See ya' there.

Jim

and they dont actually finish the charge big deal

how novel a "non constant" constant current charger if you measure a small enough time all cc/cv chargers fall into this as the current will be a constant for n milliseconds

thats one of the most daftest ideas and the way to kill a cell

DOH which is a current limited constant voltage charger which is perfectly normal cc/cv charge cycle

Will you people please change the Subject on these posts. The original was for an e-mail address.

Red S.

er pot kettle black

| DOH which is a current limited constant voltage charger which is | perfectly normal cc/cv charge cycle

You two have convinced me of the error of my ways! I see it now! It's so simple ... { spoilers follow }  All chargers of all sorts are CC/CV chargers!

(Since a CC charger is just a CC/CV charger that spends no time in CV mode, and a CV charger is just a CC/CV charger that spends no time in CC mode. And you don't really need a constant voltage output to be a CV charger, and a CC charger is still a CC charger, even if the current changes.)

Why didn't I see it before? It's so simple in retrospect!

(Really, I should have just known better than to get involved in the first place. `Don't feed them', they say. I'll try to do better next time.)