Hey guys, if anyone knows how this battery saver circuit woks let me know. I'm having trouble with the battery turn on voltage 🙁
I've connected it to a variable power supply and I have installed the appropriate resistors so it will cut off at the desired low voltage (which it does correctly) but when I turn up the voltage on my power supply again it doesn't turn back on as it should. Am I missing something?? I have made it to spec. I'm fairly sure I have made it correctly.
Any help would be extremely appreciated as it's the only thing left to get my project finished.
The link below
Battery Saver Kit for Rechargeable Lithium and SLA Batteries | Jaycar Electronics
I've connected it to a variable power supply and I have installed the appropriate resistors so it will cut off at the desired low voltage (which it does correctly) but when I turn up the voltage on my power supply again it doesn't turn back on as it should. Am I missing something?? I have made it to spec. I'm fairly sure I have made it correctly.
Any help would be extremely appreciated as it's the only thing left to get my project finished.
The link below
Battery Saver Kit for Rechargeable Lithium and SLA Batteries | Jaycar Electronics
An externally hosted image should be here but it was not working when we last tested it.
What hysteresis is achieved? Without a schematic its sounds like the hysteresis gets changed depending on the battery tech that is somehow selected?
The thing is I thought I had made it to specification and when I lower the voltage of the attached power supply it actually cuts off at the correct voltage I had set it up to be BUT when I increase the voltage it doesn’t turn back on as it should, so I mucked around and I couldn’t get it working so I thought I had a faulty kit in some way so I purchased another one and it does the same thing and that kind of tells me I’m missing something either in the tuning of the pot or I have installed the wrong resistors or what ever else. The weird thing is if I put my finger across the Ru resister (4.7m ohms) it turns back on. According to the instructions replacing the Ru resistor value is supposed to be the turn on voltage??
Thankyou so much!!🙂
I’ve attached a circuit diagram
Battery 20180325 152349 — imgbb.com
Battery 20180325 152602 — imgbb.com
Thankyou so much!!🙂
I’ve attached a circuit diagram
Battery 20180325 152349 — imgbb.com
Battery 20180325 152602 — imgbb.com
Are you using the specified opamp ?
RH sets the hysteresis. If you remove that (as a test) then the circuit should be super critical and turn on and off within a few millivolts of the set voltage. You might find RH needs to be much higher in value than you might think.
RH sets the hysteresis. If you remove that (as a test) then the circuit should be super critical and turn on and off within a few millivolts of the set voltage. You might find RH needs to be much higher in value than you might think.
Q1 is a PSMN1R2-30YL
IC1 is an MCP6541
I have changed RH to a 2.7m and also down to 1.5m with no luck in turning back on (both made it more weird)
It cuts off at the desired voltage but won’t turn back on.
So I have removed RH completely and now it cuts off at 11.3v and turns back on at 11.5V and this is the first time it has turned back on haha which may have to do if I can’t get it working correctly, I would like it to cut off at 13.2v and turn on again when the voltage is higher than 13.2v for the 4 cell lithium ion pack.
Cutting off at 11.5V is getting towards the dangerous end of the scale.
HANG ON haha update:
I have it working!! What I did is remove the RH resistor completely then I replaced the RU 4.7m with a 5.6m resister AND now if the voltage is lower than 13.2v is cuts off and if the voltage is higher than 13.2v it turns on which is want I want….. finaly!!!
I think it defies the instructions BUT it is doing what it needs to be so I’ll not touch it anymore haha
IC1 is an MCP6541
I have changed RH to a 2.7m and also down to 1.5m with no luck in turning back on (both made it more weird)
It cuts off at the desired voltage but won’t turn back on.
So I have removed RH completely and now it cuts off at 11.3v and turns back on at 11.5V and this is the first time it has turned back on haha which may have to do if I can’t get it working correctly, I would like it to cut off at 13.2v and turn on again when the voltage is higher than 13.2v for the 4 cell lithium ion pack.
Cutting off at 11.5V is getting towards the dangerous end of the scale.
HANG ON haha update:
I have it working!! What I did is remove the RH resistor completely then I replaced the RU 4.7m with a 5.6m resister AND now if the voltage is lower than 13.2v is cuts off and if the voltage is higher than 13.2v it turns on which is want I want….. finaly!!!
I think it defies the instructions BUT it is doing what it needs to be so I’ll not touch it anymore haha
It is a slightly unusual circuit because it relies on the comparator being able to accept input voltages not just equal to the supply but also above it... which that particular device can do.
for low voltage cutoff i use this: XH M609 new DC voltage protection module Low voltage disconnect protection Output 6 60V D1 009-in Replacement Parts from Consumer Electronics on Aliexpress.com | Alibaba Group
ive tried a few voltage compactors but they didn’t really do what was wanted, so i found this board. which was a lot easier to set voltage thanks to built in display 🙂
oh and its got a built in dc-dc converter to power it 🙂. which is one less thing to sort out 🙂
its so cheap its, why not enjoy easier life 🙂. i wonder how long it will last though... ? caps? well my 2 are still going, not used them much over the last few months, built into batt packs.
ive tried a few voltage compactors but they didn’t really do what was wanted, so i found this board. which was a lot easier to set voltage thanks to built in display 🙂
oh and its got a built in dc-dc converter to power it 🙂. which is one less thing to sort out 🙂
its so cheap its, why not enjoy easier life 🙂. i wonder how long it will last though... ? caps? well my 2 are still going, not used them much over the last few months, built into batt packs.
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A relay and a LED display is going to use a lot of current.
Unless LED isn't on all the time and is just used for set up ?
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