Tp4056 reverse voltage protection

egam

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I have all of the components now to charge batteries using tp4056 circuits I purchased from ebay. The only problem is they have no reverse voltage protection as stated in the description.

With theopus, I can accidentally put a battery in backwards without harm.

For those who use the tp4056, what is your experience with reverse voltage? What protection if any do you use?
If not, have any of the tp 4056 circuits failed? Do they fail safe? Meaning no burning.
 
i build my board with positiv up, aiming at the tp4056, so all blame would land on me for not installing them correctly, never happened so far though
 
I got the tp4056 with reverse protection, it works
 
Same as Maj. If you "really" wanna add extra protection, you could always put a 3.3V LED in reverse to the TP charge, and add a schottky diode (I think that's the right one) in the right direction for charging. That way when you put the cell in backwards the schottky will keep the charge controller from blowing up, and the LED will light up.

That's the simple explanation, anyways. It might be a bit more than that; I'm not quite that familiar with circuits yet.
 
I think the simplest solution is get tp4056 with protection, they're dirt cheap
 
The item is no longer listed, though Im sure the seller has more

image_hygnme.jpg

That's 15pcs for $5
 
I've been using these:
http://www.ebay.co.uk/itm/162198303412

The listing states "Please do not connect the output reversely, otherwise it may burn the chip."

Today I accidentally connected a battery reversed and released some magic white smoke, so it is true. :(
I switched it off pretty quick and it appears to still work, but just to be on the safe side I'm going to toss it anyway since they're so cheap.
 
watts-on said:
I've been using these:
http://www.ebay.co.uk/itm/162198303412

The listing states "Please do not connect the output reversely, otherwise it may burn the chip."

Today I accidentally connected a battery reversed and released some magic white smoke, so it is true. :(
I switched it off pretty quick and it appears to still work, but just to be on the safe side I'm going to toss it anyway since they're so cheap.

Yeah thats the one without protection, you can compare the 2, the protection circuit is betweenthe battery terminals
 
I already killed 10th of those by not paying attention when putting them in. My solution: Snce they're dirt cheap, buy more and replace the ones you killed :D
 
Why buy more, even though they are cheap, when you can get some schottky's for 100's for a few dollars and put them in place. I know it will take a few extra parts than just the diodes, as the charge controller needs to take readings to know how much voltage is in the cell which requires feedback to the chip.

Or, since the cells have a dimple around the positive end of the cells, make sure that end is "always" pointing to the positive end of the holder.
 
Korishan said:
Why buy more, even though they are cheap, when you can get some schottky's for 100's for a few dollars and put them in place. I know it will take a few extra parts than just the diodes, as the charge controller needs to take readings to know how much voltage is in the cell which requires feedback to the chip.

Or, since the cells have a dimple around the positive end of the cells, make sure that end is "always" pointing to the positive end of the holder.

If you get the reverse polarity protected ones, do you still need the schottky diodes?
 
I've looked at several of those TP's boards, and I haven't seen any that are "reverse polarity protected". There is a protection circuit, but that's not for polarity. That's for under/over voltage. Mostly for under-voltage as that board is designed to have the load go "through" the board. It's a protection to keep the 18650 from being drained below a set amount (not sure what this atm).
In the description of several of those units, it specifically states to not get polarity wrong as it may blow the chip. I take that as there is not polarity protection. If there were, there'd not need to be that warning.

I was thinking and remembering from youtube, you'd kind of need to have a dual diode setup so that no matter how the power came in, it went to the correct ends of the cell. There are several schematics for polarity protection boards. With and without led warning lights. The reason for the schottky diodes is they are better at handling the loads of charging with little power loss. A diode by it's very nature will lose some power to heat. Schottky's are better than standard diodes.
 
Korishan it's reverse polarity protection, all the tp4056 variants have under/over volt protection. I would have a lot of dead tp4056 if it didn't have reverse polarity protection. Protection is limited to 3A though, so if you do it with a deadish cell it should be fine, a cell with a reasonable charge could definitely do more than 3A burst.

Also not sure if people are aware of this but there's a resistor that controls charge current, you can either replace the resistor to lower current or wire a potentiometer to have variable charge current, add a volt/current display and it's quite nice, especially for bringing up low V cells.Resistor settings inthedatasheet

image_ydeutc.jpg
 
RobertBaumer said:
I guess this is it for the US folks

10PCS Micro USB 5V 1A 18650 Lithium Battery Charger Board With Protection Module

http://www.ebay.com/itm/10PCS-Micro...731497?hash=item1eacc6d829:g:1G4AAOSwvg9XdxhI

Thanks for the Link Robert! I ordered some today. I ordered extra so I can test what happens when you hook them up backwards.

I will do a side by side testof an unprotected and protected circuit board. Maybe even a video?

Should take about 3 weeks to get them.
 
Reverse Polarity "Protection" is not the same as "Tolerant"

The TP variant that has the protection modules are NOT "Polarity" protected. The only reason it works at low voltage is because of the VG voltage required to turn on the dual mosfets. However, if you were to leave that weak cell plugged in, it would eventually burn out the chips.

You can get a better view and explanation of this particular module on Julians video on this particular module. He discusses a bit of the datasheet at the beginning of the video. Note, the datasheet does NOT say "Reverse PolarityProtection", but mentions "Over-Charge" or "Over-Discharge" protection.


As you said:
I would have a lot of dead tp4056 if it didn't have reverse polarity protection. Protection is limited to 3A though, so if you do it with a deadish cell it should be fine, a cell with a reasonable charge could definitely do more than 3A burst.

If it was reverse "polarity" protected, it would be able to handle a better amp, and would be able to handle a "reasonable charged" cell. If it can only handle a "deadish" cell, then it's not reverse polarity protected.

Also: If you jump to time index 11min44secs of the video, Julian specifically talks about the protection portion of the board.
"A new board with an unprotected cell is equivalent to the old board with a protected cell because the protected cell has those battery protection components inside it so they don't need to be on the charger board. In the case of the bottom board, the protection components are on the board so they don't have to be in the cell."

I have never heard of a battery protection circuit that is on the cell (aka CID) that is reverse polarity.

If you want to get the most out of your TP4056 charging modules, make sure you do not plug them in backwards. Each time you stress the chips, you weaken their ability to function properly. Sure they are cheap modules, but why waste money on replacement parts from laziness. The 18650's are easily recognizable as which end is positive and which is negative. The positive has a button like raised end just like "any" other common battery. And they even have a crease around the positive end as well. How can you not see that? Even a blind person could put these cells in a charger the correct way.

Ok, that was my rant for the week. Please continue with your regularly scheduled charging/building
 
Korishan said:
Reverse Polarity "Protection" is not the same as "Tolerant"

The TP variant that has the protection modules are NOT "Polarity" protected. The only reason it works at low voltage is because of the VG voltage required to turn on the dual mosfets. However, if you were to leave that weak cell plugged in, it would eventually burn out the chips.

You can get a better view and explanation of this particular module on Julians video on this particular module. He discusses a bit of the datasheet at the beginning of the video. Note, the datasheet does NOT say "Reverse PolarityProtection", but mentions "Over-Charge" or "Over-Discharge" protection.


As you said:
I would have a lot of dead tp4056 if it didn't have reverse polarity protection. Protection is limited to 3A though, so if you do it with a deadish cell it should be fine, a cell with a reasonable charge could definitely do more than 3A burst.

If it was reverse "polarity" protected, it would be able to handle a better amp, and would be able to handle a "reasonable charged" cell. If it can only handle a "deadish" cell, then it's not reverse polarity protected.

Also: If you jump to time index 11min44secs of the video, Julian specifically talks about the protection portion of the board.
"A new board with an unprotected cell is equivalent to the old board with a protected cell because the protected cell has those battery protection components inside it so they don't need to be on the charger board. In the case of the bottom board, the protection components are on the board so they don't have to be in the cell."

I have never heard of a battery protection circuit that is on the cell (aka CID) that is reverse polarity.

If you want to get the most out of your TP4056 charging modules, make sure you do not plug them in backwards. Each time you stress the chips, you weaken their ability to function properly. Sure they are cheap modules, but why waste money on replacement parts from laziness. The 18650's are easily recognizable as which end is positive and which is negative. The positive has a button like raised end just like "any" other common battery. And they even have a crease around the positive end as well. How can you not see that? Even a blind person could put these cells in a charger the correct way.

Ok, that was my rant for the week. Please continue with your regularly scheduled charging/building

Well I need some help from blind people, because I put them in backwards all the time. I want them to be dummy proof.

When I'm loading 20 cells and trying to be quick about it, it happens.


egam said:
Korishan said:
Reverse Polarity "Protection" is not the same as "Tolerant"

The TP variant that has the protection modules are NOT "Polarity" protected. The only reason it works at low voltage is because of the VG voltage required to turn on the dual mosfets. However, if you were to leave that weak cell plugged in, it would eventually burn out the chips.

You can get a better view and explanation of this particular module on Julians video on this particular module. He discusses a bit of the datasheet at the beginning of the video. Note, the datasheet does NOT say "Reverse PolarityProtection", but mentions "Over-Charge" or "Over-Discharge" protection.


As you said:
I would have a lot of dead tp4056 if it didn't have reverse polarity protection. Protection is limited to 3A though, so if you do it with a deadish cell it should be fine, a cell with a reasonable charge could definitely do more than 3A burst.

If it was reverse "polarity" protected, it would be able to handle a better amp, and would be able to handle a "reasonable charged" cell. If it can only handle a "deadish" cell, then it's not reverse polarity protected.

Also: If you jump to time index 11min44secs of the video, Julian specifically talks about the protection portion of the board.
"A new board with an unprotected cell is equivalent to the old board with a protected cell because the protected cell has those battery protection components inside it so they don't need to be on the charger board. In the case of the bottom board, the protection components are on the board so they don't have to be in the cell."

I have never heard of a battery protection circuit that is on the cell (aka CID) that is reverse polarity.

If you want to get the most out of your TP4056 charging modules, make sure you do not plug them in backwards. Each time you stress the chips, you weaken their ability to function properly. Sure they are cheap modules, but why waste money on replacement parts from laziness. The 18650's are easily recognizable as which end is positive and which is negative. The positive has a button like raised end just like "any" other common battery. And they even have a crease around the positive end as well. How can you not see that? Even a blind person could put these cells in a charger the correct way.

Ok, that was my rant for the week. Please continue with your regularly scheduled charging/building

Well I need some help from blind people, because I put them in backwards all the time. I want them to be dummy proof.

When I'm loading 20 cells and trying to be quick about it, it happens.
Korishan,I looked up schottkey diodes. The forward current voltage drop is 0.6V at 1 amp. A lithium ion charging circuit can Not tolerate a .6 volts drop. I'm not sure how you were using it?
 
Schottky Diodes can have many Vf ranges. However, for our application, you can them as low as 600mV

http://www.mouser.com/ProductDetail...=sGAEpiMZZMtQ8nqTKtFS/FT88w1K3SZNslYDAmraaXE=

Product:Schottky Diodes
Mounting Style:Through Hole
Package / Case:DO-35
If - Forward Current:-
Vrrm - Repetitive Reverse Voltage:20 V
Vf - Forward Voltage:600 mV
Ifsm - Forward Surge Current:15 A
Configuration:Single
Technology:Si
Ir - Reverse Current:5 uA
Maximum Operating Temperature:+ 125 C
Brand:Vishay Semiconductors
Height:1.7 mm
Length:3.9 mm
Operating Temperature Range:+ 125 C
Pd - Power Dissipation:400 mW
Termination Style:Through Hole
trr - Reverse Recovery time:10 ns
Type:Small Signal Schottky Diode
Vr - Reverse Voltage:20 V

So, as you can see, a Schotty could be used in our application. That diode also has a 20V reverse protection, and 5uA reverse current. So it's quite capable of handling the job.
 
Korishan said:
Schottky Diodes can have many Vf ranges. However, for our application, you can them as low as 600mV

http://www.mouser.com/ProductDetail...=sGAEpiMZZMtQ8nqTKtFS/FT88w1K3SZNslYDAmraaXE=

Product:Schottky Diodes
Mounting Style:Through Hole
Package / Case:DO-35
If - Forward Current:-
Vrrm - Repetitive Reverse Voltage:20 V
Vf - Forward Voltage:600 mV
Ifsm - Forward Surge Current:15 A
Configuration:Single
Technology:Si
Ir - Reverse Current:5 uA
Maximum Operating Temperature:+ 125 C
Brand:Vishay Semiconductors
Height:1.7 mm
Length:3.9 mm
Operating Temperature Range:+ 125 C
Pd - Power Dissipation:400 mW
Termination Style:Through Hole
trr - Reverse Recovery time:10 ns
Type:Small Signal Schottky Diode
Vr - Reverse Voltage:20 V

So, as you can see, a Schotty could be used in our application. That diode also has a 20V reverse protection, and 5uA reverse current. So it's quite capable of handling the job.
Like I said .6V (600MV) won't work on the output side of a tp4056.
If you hook it in series with the 18650, and your tp4056 is outputing 4.2 volt, the 18650 is only going to see 3.6V. The tp4056 will stop charging long before the 18650 is charged.


Ok, ok, I think I found a website that provides an answer.

A 6 amp capable Schotkey diode across the output terminals of the tp4056.
And then put a ptc self resetting fuse in series with the battery.

So the resistance is very low on the ptc I selected. It's 0.07 ohms. So only .07 volts drop at 1 amp, but only .007 volts drop at 100 mAmps. I think it will do the trick.

https://electronics.stackexchange.c...li-ion-reverse-polarity-protection-when-prote

http://www.mouser.com/Search/m_ProductDetail.aspx?Littelfuse/RUEF250/&qs=hv6pn79dJPQsHwuAgSfH9w==
 
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