mrarroyo
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Post by mrarroyo on Feb 23, 2011 11:23:37 GMT
The li-ion batteries require an special charger different from the ones used for metal hydride or cadmium batteries. Just thought I should post so.
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Post by JohnnyBlue on Feb 23, 2011 14:20:59 GMT
The li-ion batteries require an special charger different from the ones used for metal hydride or cadmium batteries. Just thought I should post so. Can you explain why? I'd have thought that as long as the voltage is correct and the amperage is appropriate, any charger will do, no?
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Post by PinkFloyd on Feb 23, 2011 21:53:44 GMT
If charged incorrectly a Li ion battery will literally "explode" (like a mini bomb).... I am going to experiment with these 500mAh batteries and do a bit more "research".....
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Post by PinkFloyd on Feb 23, 2011 22:03:40 GMT
Reading more about these batteries..... "Supplied with protection circuit for short circuit protection, over voltage, over discharge, etc.." so I am going to try a charge time of 4 hours in the Neco.... will let you know what happens
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Post by PinkFloyd on Feb 24, 2011 20:02:30 GMT
I think the little charging circuit onboard the NECO V2 will be fine with the 500 mAh Li ion battery, I am experimenting with charge times and will let you know the ideal charge time by the end of the week.
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Post by PinkFloyd on Feb 24, 2011 21:22:02 GMT
I have been in touch with NECO and his circuit is set at 20mA so IF it will charge the Li-ion 500mAh battery it will take 25 hours. This may not seem practical BUT with almost 3 times more juice the amp will last ages before it requires another charge. I am sending Neco one of the batteries to try, see what he comes up with
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Post by PinkFloyd on Feb 25, 2011 23:40:16 GMT
I have charged the 500mAh battery for 25 hours and can confirm that it is perfectly ok to use in the NECO. It has accepted a full charge and remained as cool as a cucumber throughout the charge process. I am going to monitor the playback time now with a pair of Goldring DR-150, volume control set to 10 o' clock position.
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Post by PinkFloyd on Feb 26, 2011 10:04:47 GMT
I have informed Neco about the battery test and will be sending him one to try.... The existing circuit charges at 20mA which takes 24 hours to achieve a full charge.... I am going to make a small revision (1 resistor) to the charging circuit to up that to 50mA so that a full charge will only take 10 hours to achieve. 24 hours IS a bit long isn't it? Will keep you posted on events.
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Post by PinkFloyd on Feb 27, 2011 14:21:03 GMT
OK folks..... time for a bit of maths (not one of my strongest subjects!) here we go: Right, the Neco circuit charges at 21mA per hour so we know that a 500mAh battery will take 24 hours to charge: 500 / 21 = 23.80 OK... with me so far? Right, we now want to get the Neco to charge faster so how do we do it? I will tell you...... In the Neco charging circuit current = 0.65 / R. At the moment there is a 33 ohm resistor so we calculate thus: 0.65 / 33 = 19mA So the actual charging time will be 500 / 19 = 26 hours. Absolute pants! We don't want to have to wait 26 hours do we? OK.... the transistors on the Neco are good for 100mA so let us do a few more calculations: Let's swap the 33 ohm resistor for a 15 ohm resistor and see what happens..... 0.65 / 15 = 43mA So, 500 / 43 = 11 hours Still too long IMO so let's crank the output up a little bit more using a 10 ohm resistor: 0.65 / 10 = 65mA so, 500 / 65 = 7.6 hours.... MUCH better and we are not straining the transistors as they are good for 100mA. OK.... you want to know what to fit where don't you? Right..... in the blank space there normally resides a 33 ohm resistor: Remove this resistor and fit a 10 ohm resistor in its place: Your little Neco will now charge a 500mAh Li ion battery to full capacity in just under 8 hours! I have fully tested this and it works a treat so don't worry, it is A OK 100% good to do. One happy Neco, fully charged, ready to go!
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Post by dicky on Feb 27, 2011 18:12:30 GMT
That's great news, Mike. Presumably NECO set the charging time for 10 hours for the original battery so it would charge slowly overnight? Oh, and you have PM.
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Post by PinkFloyd on Mar 3, 2011 20:54:33 GMT
I sent Neco one of the batteries and he has confirmed that, YES, it is perfectly good to use the Li-ion with the 10ohm resistor mod and I quote:
"Received the battery yesterday. Thank you.
Today I did a charge testing with a 10 ohms resistor. Current going-in was measured at 64mA. Battery cleverly stopped taking further charge after it was full which was very nice. I dont know why I did not consider this option before and thank you for this.
I can modify the circuit a little so when battery stops taking charge the red LED at the back will turn-off also so the user can actually see that charging is finished which is a quite nice feature."
I have spotted a 600mAh Li-Ion battery and will be trying this too, this will give even MORE playback time!!
Mike.
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Post by PinkFloyd on Mar 3, 2011 21:01:38 GMT
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elysion
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Post by elysion on Mar 3, 2011 21:20:55 GMT
Nice. Really impressive playback time. The 300mA NiMH that could be ordered from Neco as option was already impressive. But 500mA or 600mA? WOW!Where does it end? Li-Polymer technique is already maxed out, but there will be other technical improvement for sure. What about a portable amp that could be charged once before you go into holidays for two weeks (and that still has some reserves when you arrive back home)?
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Post by PinkFloyd on Mar 3, 2011 21:24:43 GMT
Nice. Really impressive playback time. The 300mA NiMH that could be ordered from Neco as option was already impressive. But 500mA or 600mA? WOW!Where does it end? Li-Polymer technique is already maxed out, but there will be other technical improvement for sure. What about a portable amp that could be charged once before you go into holidays for two weeks (and that still has some reserves when you arrive back home)? I don't think the Neco will be far off two weeks playback with a 600mAh battery.... obviously not 14 x 24 hours but should be good for a couple of weeks "normal" usage on one full charge?
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elysion
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Post by elysion on Mar 3, 2011 22:44:04 GMT
I don't use the Neco Portable V2 much at home. But it's a perfect amp if I'm on the road or in the home of friends. But sometimes I'm so attracted by it's sound signature with somes 'phones that it gets my main amp for some time. Even the 300mA NiMH battery is enough for a lot of use and I have only to recharge very seldom. One suggestion: NiMH and Li-Ion-Polymer battery are very different beasts. They have other charateristics and have to be used differently to max out the live and/or capacity of the battery. en.wikipedia.org/wiki/Nickel-metal_hydride_batteryen.wikipedia.org/wiki/Lithium-ion_batteryen.wikipedia.org/wiki/Lithium-ion_polymer_batteryI'm no expert, but AFAIK a Li-Ion-Polymer battery would be perfect for someone that uses the Neco Portable constantly with his iPod. A NiMH battery could be a better choice for someone like me, who uses the Neco Portable not everyday. I guess the NiMH battery would have a greater lifespan for my typical use. But for those who use it almost always, the Li-Ion-Polymer would have great advantages. Li-Ion/Li-Ion-Polymer batteries don't like to be total discharged. That's also a point for the NiMH's which are tougher in this regard (for applications where the amp isn't used over long time). There are more differences between NiMH's and Li-Ion-Polymer's (see wikipedia links above). Is there also a difference in sound quality?
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Post by PinkFloyd on Mar 3, 2011 22:54:19 GMT
Li Ion starts degenerating from day one, whether you use it or not so it is perfect for somebody who uses the amp frequently. The built in circuit protects against overcharge and discharge so you have no real worries there. The benefits? Well........ 600mAh! More benefits / disadvantages here: www.greenbatteries.com/libafa.html
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Post by PinkFloyd on Mar 3, 2011 22:55:48 GMT
Good question! I haven't got a clue is the answer
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xerxes
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Post by xerxes on Mar 4, 2011 1:51:12 GMT
I use a lot of Ni-MH rechargeable batteries, I use them in all my remote controls, torches, bicycle lights etc. and a 9v PP3 in a headphone amp. I had a crummy battery charger that would take 8 to 12 hours to charge AA and AAA and about 16 hours to charge a PP3. As I use so many rechargeables I wanted something better, so got one of these: www.tantronics.co.uk/acatalog/Ansmann_Energy_8_PLUS_Battery_Charger.htmlI've had it for about a month or so and I'm very pleased with it, it charges AA and AAA in an hour or two and PP3s in about 4 or 5 hours, which is significantly quicker than the headphone amp runs them down.
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Deleted
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Post by Deleted on Mar 4, 2011 2:19:33 GMT
I use a lot of Ni-MH rechargeable batteries, I use them in all my remote controls, torches, bicycle lights etc. and a 9v PP3 in a headphone amp. I had a crummy battery charger that would take 8 to 12 hours to charge AA and AAA and about 16 hours to charge a PP3. As I use so many rechargeables I wanted something better, so got one of these: www.tantronics.co.uk/acatalog/Ansmann_Energy_8_PLUS_Battery_Charger.htmlI've had it for about a month or so and I'm very pleased with it, it charges AA and AAA in an hour or two and PP3s in about 4 or 5 hours, which is significantly quicker than the headphone amp runs them down. Owen I often wonder what effect rapid charging has on the life expectancy of these batteries. Even at the lower charge rate, they can get pretty damn warm.I even had a charger burn out and destroy a battery too. Alex
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xerxes
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Post by xerxes on Mar 4, 2011 2:48:18 GMT
I don't think this a rapid charger in the usual sense of the word, I think it's just more intelligent than my old one. When you put the batteries in, it refreshes and pre-charges, according to the flashing lights on the front anyway. In addition, batteries will finish charging at different times, so it's obviosuly monitoring them individually and presumably not overcharging them.
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Post by JohnnyBlue on Mar 4, 2011 17:35:49 GMT
FWIW, I also use lots of re-chargeables (NiMH and NiCd). It is my experience that NiMH have larger capacities and less 'memory' problems (obviously!), BUT that they discharge more quickly when/if they're not used, whereas the NiCds hold their charge better.
I've also ruined whole sets of NiMHs through charging them a few times (5 or 6 times?) in 'rapid' chargers (e.g., about 5 hours for 2500mAh). Mine seem to last longer when charged slowly (say 20 - 24 hours).
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xerxes
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Post by xerxes on Mar 4, 2011 21:31:28 GMT
Yes they do, although they do hold their charge longer if you keep them cool and dry, Ni-Cds as well. So you can put them in a sealed container and store them in the refrigerator if you want them to hold their charge a bit longer while not in use.
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mrarroyo
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Our man in Miami!
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Post by mrarroyo on Mar 4, 2011 23:26:16 GMT
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Deleted
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Post by Deleted on Mar 5, 2011 16:44:32 GMT
I agree with Miquel !!
Eneloop (Sanyo) are the best of all LSD NIMH batteries. I have tested a lot of them (different brands) for a Dutch photo magazine and these came out on top. obviously I couldn't test how well they behave over a long period of time but I still use them in almost all AA and AAA powered devices, except inclocks, these need 1.3V minimum mostly. They still outperform all other LSD batteries I still own.
Best cheapest AA/AAAchargers (-deltaV) : 1: Voltcraft IPC-1 (or IPC-1L) = Lacrosse BC900 2: Maha MH-C401S 3: hape NV70 (also sold under different brands) also does PP (without -dV as this is not really feasable)
In case someone is wondering LSD stands for Low Self Discharge. I do not use LSD against my schizophrenic disorder... ;-)
prefered choice for digital camera's and other stuff one rarely uses but wants to be on 'stand-by' when taken out of the drawer. there is nothing more annoying then grabbing your camera and not even being to make 1 or a few shots while remembering having chaged the batteries not even that long ago.
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Deleted
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Post by Deleted on Mar 15, 2011 16:59:23 GMT
I sent Neco one of the batteries and he has confirmed that, YES, it is perfectly good to use the Li-ion with the 10ohm resistor mod and I quote: "Received the battery yesterday. Thank you.
Today I did a charge testing with a 10 ohms resistor. Current going-in was measured at 64mA. Battery cleverly stopped taking further charge after it was full which was very nice. I dont know why I did not consider this option before and thank you for this.
I can modify the circuit a little so when battery stops taking charge the red LED at the back will turn-off also so the user can actually see that charging is finished which is a quite nice feature."I have spotted a 600mAh Li-Ion battery and will be trying this too, this will give even MORE playback time!! Mike. Hi, Mike I just bought a 600 mAh Li-Ion from eBay. Here is the link: cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=140490732116&ssPageName=STRK:MEWNX:ITI am looking forward to adapting it to my Neco portable. Any suggestions as to the resistor value in the charging circuit? Thanks!
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