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I am currently repackaging my nvna and would like to include a (much) bigger battery. What is the biggest battery capacity (Amp-Hours) I could use with the IP5303 charging circuit? Looks to me like there is no limit since the IP5303 will limit the charging current so the initial constant current phase of charging will simply take longer. Why does the 450mAh battery supplied with the device include a built in circuit for over drain protection etc? The IP5303 already has "Input over-voltage, over-current, battery over-charge, over-drain, over-current protection" built in. I'm thinking a fat cell phone Lithium Ion battery should be fine as reported by Larry Rothman here... /g/nanovna-users/photo/0/40?p=Created,,,20,1,40,0 (I was at a flea market a couple of months ago and there was a seller who had a lot of new cylindrical LiIon cells about 3Ah as I recall. They were very cheap, but I did not have a nvna then. I wish now that I had bought a few.)
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18650 cells (especially cheap ones ) rarely have the current capacity they are marked with. I bought 20 cheap 3ah cells from amazon and all of them were closer to 1.5.
Cheap batteries can be a false economy.
Alan
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On Nov 14, 2019, at 12:45 PM, Nick <g3vnc@...> wrote:
?I am currently repackaging my nvna and would like to include a (much) bigger battery.
What is the biggest battery capacity (Amp-Hours) I could use with the IP5303 charging circuit? Looks to me like there is no limit since the IP5303 will limit the charging current so the initial constant current phase of charging will simply take longer.
Why does the 450mAh battery supplied with the device include a built in circuit for over drain protection etc? The IP5303 already has "Input over-voltage, over-current, battery over-charge, over-drain, over-current protection" built in.
I'm thinking a fat cell phone Lithium Ion battery should be fine as reported by Larry Rothman here...
/g/nanovna-users/photo/0/40?p=Created,,,20,1,40,0
(I was at a flea market a couple of months ago and there was a seller who had a lot of new cylindrical LiIon cells about 3Ah as I recall. They were very cheap, but I did not have a nvna then. I wish now that I had bought a few.)
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All lithium -cells- need to come with overcharge, overcurrent (ie:shorting its terminals), undervoltage and overtemp protection (and balancing sometimes is also built-in).
And that is just that small board on the cell itself !??
The IP5303's charging circuit knows nothing about the physical condition of the Li cell.If the IP5303 fails catastrophically, you want the battery to protect itself.
I have several two-way radio batteries that have disabled themselves due to a fault somewhere but when I opened them up, the individual cells were fine.
I also have 3.6V cells where the protection module shut off the output voltage. I use those cells in other projects.
Better safe than fire......
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On Thursday, November 14, 2019, 12:45:10 p.m. GMT-5, Nick <g3vnc@...> wrote: I am currently repackaging my nvna and would like to include a (much) bigger battery. What is the biggest battery capacity (Amp-Hours) I could use with the IP5303 charging circuit?? Looks to me like there is no limit since the IP5303 will limit the charging current so the initial constant current phase of charging will simply take longer. Why does the? 450mAh battery supplied with the device include a built in circuit for over drain protection etc?? The IP5303 already has "Input over-voltage, over-current, battery over-charge, over-drain, over-current protection" built in. I'm thinking a fat cell phone Lithium Ion battery should be fine as reported by Larry Rothman here... /g/nanovna-users/photo/0/40?p=Created,,,20,1,40,0 (I was at a flea market a couple of months ago and there was a seller who had a lot of new cylindrical LiIon cells about 3Ah as I recall.? They were very cheap, but I did not have a nvna then.? I wish now that I had bought a few.)
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Oh - and as for the size of a larger battery - several forum members including myself have used larger cellphone batteries up to 1500mAH.
You can just solder the wires directly to the + & - pins of the battery.? The IP5303 essentially charges the battery according to its instantaneous voltage instead of just pushing constant current into it, just like it would be charged in a cellphone - just don't use a really old cell for this.
Any 18650 cell will be way more than enough for the nano's needs.
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On Thursday, November 14, 2019, 1:10:11 p.m. GMT-5, Larry Rothman <nlroth@...> wrote: All lithium -cells- need to come with overcharge, overcurrent (ie:shorting its terminals), undervoltage and overtemp protection (and balancing sometimes is also built-in). And that is just that small board on the cell itself !?? The IP5303's charging circuit knows nothing about the physical condition of the Li cell.If the IP5303 fails catastrophically, you want the battery to protect itself. I have several two-way radio batteries that have disabled themselves due to a fault somewhere but when I opened them up, the individual cells were fine. I also have 3.6V cells where the protection module shut off the output voltage. I use those cells in other projects. Better safe than fire...... ? ? On Thursday, November 14, 2019, 12:45:10 p.m. GMT-5, Nick <g3vnc@...> wrote: I am currently repackaging my nvna and would like to include a (much) bigger battery. What is the biggest battery capacity (Amp-Hours) I could use with the IP5303 charging circuit?? Looks to me like there is no limit since the IP5303 will limit the charging current so the initial constant current phase of charging will simply take longer. Why does the? 450mAh battery supplied with the device include a built in circuit for over drain protection etc?? The IP5303 already has "Input over-voltage, over-current, battery over-charge, over-drain, over-current protection" built in. I'm thinking a fat cell phone Lithium Ion battery should be fine as reported by Larry Rothman here... /g/nanovna-users/photo/0/40?p=Created,,,20,1,40,0 (I was at a flea market a couple of months ago and there was a seller who had a lot of new cylindrical LiIon cells about 3Ah as I recall.? They were very cheap, but I did not have a nvna then.? I wish now that I had bought a few.)
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I think you can use 220 Ah battery (220'000 mAh) and it should works ok
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On Thu, Nov 14, 2019 at 06:18 PM, Larry Rothman wrote: Any 18650 cell will be way more than enough for the nano's needs. Thanks Larry. I'll try and find a "quality" one.
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On Fri, Nov 15, 2019 at 11:44 AM, QRP RX wrote:
I think you can use 220 Ah battery (220'000 mAh) and it should works ok
It's a shame they all appear to be 12V ;)
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450mAh is... Not suitable for NanoVNA
1. Stand-by draw
2. Charge circuit pushes over 1A( over 2C rate )
My battery already swelled( PCB/LCD curved slightly )
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On Mon, Nov 18, 2019 at 01:58 PM, RFy wrote: 450mAh is... Not suitable for NanoVNA
2. Charge circuit pushes over 1A( over 2C rate )
My battery already swelled( PCB/LCD curved slightly ) Yes. This issue has been reported before (posts #3096, #4533, #6288 etc.) Supplied nvna battery spec is here... Maximum Charging Current specified as 450mA. IP5303 Charging current specified as 1.2A typ and 1.4A max. There does not appear to be any way to reduce this without additional circuitry. So worst case the 450mAh battery might be charged at 1.4/0.45 = 3.1C ! Qualifies as ultra fast charging... Charge rate might depend on the source. If the nvna is being charged from a standard downstream USB2 port, such as those fitted to this computer, then the charge current could be limited to 500mA which is ~1.1C. Might explain why my battery was fine until I subjected it to an iPad charger! Looking longways on the nvna I can see that the pcb and rear panel are deflected by the battery swelling. Easily verified by removing one screw in the rear panel where a gap opens up between the panel and the brass spacer. I have now removed the 450mAh battery and temporarily fitted a 1100mAh ex call phone battery stuck on the rear panel. I will fit a "quality" protected 18650 cell when I assemble the repackaged nvna.
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I'm wondering if hugen is able to verify that the replacement battery control chip he is thinking of using will prevent over charging any cells.
I've translated and attached a copy of the FM9688 Mobile Power Management IC spec sheet.
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On Tuesday, November 19, 2019, 11:17:19 a.m. GMT-5, Nick <g3vnc@...> wrote: On Mon, Nov 18, 2019 at 01:58 PM, RFy wrote: 450mAh is... Not suitable for NanoVNA
2. Charge circuit pushes over 1A( over 2C rate )
My battery already swelled( PCB/LCD curved slightly ) Yes.? This issue has been reported before (posts #3096, #4533, #6288 etc.) Supplied nvna battery spec is here... Maximum Charging Current specified as 450mA. IP5303 Charging current specified as 1.2A typ and 1.4A max.? There does not appear to be any way to reduce this without additional circuitry. So worst case the 450mAh battery might be charged at 1.4/0.45 = 3.1C ! Qualifies as ultra fast charging... Charge rate might depend on the source. If the nvna is being charged from a standard downstream USB2 port, such as those fitted to this computer, then the charge current could be limited to 500mA which is ~1.1C. Might explain why my battery was fine until I subjected it to an iPad charger! Looking longways on the nvna I can see that the pcb and rear panel are deflected by the battery swelling.? Easily verified by removing one screw in the rear panel where a gap opens up between the panel and the brass spacer. I have now removed the 450mAh battery and temporarily fitted a 1100mAh ex call phone battery stuck on the rear panel. I will fit a "quality" protected 18650 cell when I assemble the repackaged nvna.
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I thought it was 1.2 amps max pass current, not actual current ?
English data sheet mentions intelligent charge levels.
Not sure if this helps, or the dsta sheet is misleading.
73 de Andy
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Quote from spec sheet - ?Charger ?Adaptive charging current control, Adaptive charging current control. Quote from spec sheet - IP5305 has integrated a voltage based fuel gauge algorithm, acquiring battery¡¯s state of charge precisely. Which in theory should regulate charging current. The world and his dog knows full well that charging a Li-Ion cell needs real care under all circumstances, so I'm puzzled by the claims that it would allow a full 1.2 amps to flow regardless. This does not make sense at all. I guess the 1.2 amp spec is only based upon what the device can handle, since there is no heatsink etc. Trickle charge current is also mentioned on the spec sheet as being 100ma, not enough to kill a 400ma cell. Am I missing something ? I wish I knew everything, but I accept that I don't ;) 73 de Andy
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On Tue, Nov 19, 2019 at 12:56 PM, Andy wrote:
Trickle charge current is also mentioned on the spec sheet as being 100ma, not enough to kill a 400ma cell.
Am I missing something ?
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Andy,
LI-ON batteries, unlike NI-mH and Nicads do not respond well to trickle charging. The LI-ON batteries used with the NanoVNA should have a small battery management board built in to limit the charging current and to cut-off when their voltage limit (~4.2V) is reached.
Most 3.7V cell phone batteries have the management pcb built in and so can be used without worry in the NanoVNA. Other 3.7V LI-ON batteries are "naked" (without a management board) and my guess is that those batteries over time will overheat, start to bulge and in other ways become defective.
- Herb
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LI-ON batteries, unlike NI-mH and Nicads do not respond well to trickle charging Agreed. But I was not saying that it should be the case, or was the case ;-) I believe that Li-Ion prefer a typical 0.5C most of the time, so at the worst case lets assume a NanoVNA charge controller was in error and allowed a full 1.2 amps to flow. That would mean that if we used a typical 2400mah cell then the problem would go away. As it just so happens, it happens to be the most unitary specification cell currently on the market. So the paranoid users should just replace their own cell with a bog standard 2400mah cell and forget about it. At worst case, it just takes a little longer to charge. As for Ni-Mh, fast charging will kill them eventually, just like cigarettes and your lungs. They contain water, and you know what happens to water when it gets hot <big-grin> The negative electrode reaction occurring in a NiMH cell is H2O + M + e? ? OH? + MH On the positive electrode, nickel oxyhydroxide, NiO(OH), is formed: Ni(OH)2 + OH? ? NiO(OH) + H2O + e? I personally suspect that there are other reasons why users have experienced failed cells in NanoVNA's. Undercharging and long periods of NO charging will produce swollen cells. Those supplied cells might have been hanging around in a Peking warehouse for years and already faulty. I left a crappy Android tablet in a drawer for 18 months, battery with no charge swelled and pushed the screen out ;-)) 73 de Andy
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To the question "Trickle charge current is also mentioned on the spec sheet as being 100ma, not enough to kill a 400ma cell."
If you read the datasheet fully, you find this lines:
#Low Battery voltage VBAT When Battery voltage lower than VBAT £¬the Boost will be shutdown 2.78 2.85 2.92 V
So in between 2.78 and 2.92V (tolerances) the device will stop operating)
#Trickle charge current ITRKL VIN=5V£¬BAT=2.7V 100 mA
#Trickle charge stop voltage VTRKL 3 V
In between 2.7V and 3V (i assume +/- tolerances) the device will Trickle Charge with lower current not to stress the battery at low charge.
So it is not charge keeping tricke charge, but stress reduction .
I assume (not written in datasheet) that below 2.7V of the battery no charging will start (under voltage shut off to prevent safety risk). There is the risk of a burning LiPo battery if a undervoltage battery is charged again. So leaving the device for a long time with 50?A discharge will destroy the battery.
#Target charge voltage VTRGT 4.2 V
#Recharge threshold VRCH 4.1 V
Charging is done up to 4.2V (switch off) and charging starts again with 4.1V (restart)
vy73 de Karsten, DD1KT
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Hallo Karsten,
Ja, if I read you correct, I 100% agree.
Vy 73 de Andy
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Hi All,
I used the battery from a Boefeng 888 which was broken down to make an Allstar node. Labelled as 2.2Ah, and includes a protection board.
73
Barry
G4MKT
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The IP5305 can not limit current to a "safe" value for the battery because it doesn't know what the battery's capacity is. It simply limits current to 1.2A or whatever the USB port can supply, whichever is lower. It's up to the design engineer to choose a battery that can handle 1.2A of charging current. Most 18650 cells are specified for at most 0.5C charge rate (some higher capacity laptop cells are even 0.25C). There are pouch cells specified up to 1C (for example in most smartphones). The cell's datasheet will state the maximum charge current. For ebay/aliexpress cells without a datasheet absolutely stay away from anything > 0.5C.
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TL;DR: if unsure, ONLY use cells >= 2400mAh and <= 10000mAh with the Nano. The reason for the upper limit is a bit more subtle; it's due to the fact that the charge cut-off current is fixed (100mA), and on higher capacity cells by the time the current falls to 100mA it is already overcharged.
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Greetings to the Battery Group :)
I have some batteries for Samsung Galaxy S3, 2100mAH, that are a just a bit smaller than the nano and would fit inside with slightly longer standoffs.
But here the question: these phone batteries have 4 connections; I can measure positive voltage on one, negative on the 3 others. Does anyone know if these 4-terminal phone batteries have internal protection, and are they safe to use as a 2-wire battery? What do the other 2 connections do, in the normal phone purpose?
Thanks, --kv5r
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Alan Zimmerman
OwO