Need a diagram for 24v Battery Monitor using LM3914 chip

[Roff]

Hiya Ron,
Eh mate thanks very much for designing that battery circuit I've been looking on the web for ages trying to find a circuit so I can monitor my 24 volt battery bank in my shed. One query as I'm inputting pure DC from a solar array I should be able to simplify the input side thru the lm317 as spikes won't be a problem. Oh if if I may dare I've got a bank of Nife batteries which float around 16.5 volts so how would I modify the circuit to suit. Silly me used my 12 volt lm3914 circuit and ended up seeing the magic smoke :cry:

Cheers Bryan

You can probably eliminate R11 and C5.
What range do you want for the NiFe battery?

 

[bryan1]

What range do you want for the NiFe battery?

Hiya Ron,
I've made up the shunt regulator that Oatleys sell as a kit and I have set the nife's to float around 16 volts so I reckon a range from 16.5 volts down to 12 volts in 0.5 volt increments would be pefect.

Cheers Bryan

 

[sprat]

RON H
I am using those experimental breadboards which just allows me to insert the parts without solder. I started from the day you post diagram. Real task now is to put all this on a circuit board and solder

Thanks

 

[Roff]

What range do you want for the NiFe battery?

Hiya Ron,
I've made up the shunt regulator that Oatleys sell as a kit and I have set the nife's to float around 16 volts so I reckon a range from 16.5 volts down to 12 volts in 0.5 volt increments would be pefect.

Cheers Bryan

Brian, I removed the filtering for the LM317. I hope your NiFe load is not noisy. There is not enough headroom to add it back unless we redesign the whole circuit.

 

[bryan1]

Hiya Ron,
Eh mate thanks for redesigning the circuit for me Now I'll sit down and have a go at making up a circuit board and get the the parts I need mainly the lm3914 which over here is over $6 each :shock: this is why with my limited knowledge I haven't undertaken designing my own as 1 simple mistake would end up being costly. Thanks again

Cheers Bryan

 

[blowouter]

Hello everybody
i wonder if this circuit works for any battery 24v no matter of the ampere this battery can handle

 

[michaelangelo]

hello sir roff, i saw your circuit, and im planning to use it to monitor 24 volts lead acid battery (two 12 volts in series), i wanna ask sir roff, what kind f resistor to use? is it 1/4 watts? or i need bigger resistor? thanks a lot sir

 

[MikeMl]

An LM3914 is nothing but a not-very-accurate voltmeter. Why not just **broken link removed**?

Using a voltmeter to determine the state of charge of a lead acid battery is not a very good way of doing it...