I would be interested in why you don't want to connect the batteries in parallel.
Also, is your bike going to be a positive ground system? Will the chassis be connected to the common battery positive? Even if you get this part to work, have you thought through how you will connect everything else to it?
I would be interested in why you don't want to connect the batteries in parallel.
I can hotswap batteries which is not possible in normal parallel since batteries with voltage difference is not recommended to be paralleled. also with this i can add completely different voltage batteries together.
My bike frame is not grounded but everything will be ran from this device's Output ground with capacitors so the switching of the batteries wont make the circuit cut out. i plan to add ads1115 to each battery and a i2c isolator (each ads1115 will get its power from the battery its monitoring so the adc has voltage reference only thing going to the mcu will be the i2c lines) which can give the mcu voltage readings of each battery and can effectively switch the battery how i program it to do. and that will be pretty much it. there are devices that exist online which achieve the same thing but they use relays and cannot switch fast enough/ cant handle my voltages or power demands.
Edit: I guess that would be 34 + 16 = 50V reverse test.
Hmm, i did some research I'm not sure, the batteries that were used when the mosfets exploded are 35v and 51v.
EDIT: il try to add them again and see if they explode again. and if the other pair explodes or first one.
@TomGeorge To answer your question i did run some tests.
when everything switched off (low gpio signal) but mcu still powered. if 36v is connected in P2 circuit turns on, 0v on the outputs. 0v gate-source voltage. if 36v connected to P1 circuit remains turned off and nothing happens. if 51v connected to P2 circuit turns on, 0v gate-source voltage for both sets of MOSFET. however, there's 6v on the output. additionally if 36v connected to P1 and 51v to P2 the same 6v remains.
If Q1 and Q2 are on and i connect 51v to P2 i get 51v on output, nothing gets hot. if i then connect 36v on P1 which is off Q4 and Q3 start to get hot and explode. Gate-Source is 0.5v on Q4 and Q3.
For anyone searching through, the working schematics are these. isolator has to be used to power the microcontroller, other tricks didn't work. INA117p is used to measure voltage from both batteries to go on adc. +15v and -15v are required for the INA to work.
Version 1 is OK for under 84v
Version 2 is OK for under 135v.
Credit goes to crutschow.19451
Ok, well I'm going to un-apologize for my circuit in post #34. It drove the collectors of the optocouplers from the divided down common battery + terminals, which appears to be what you ended up with. But it looks like the isolated 5V was the key to making it work. Anyway, I hope you'll come back and report whether it actually works on the bike or not.
Yes indeed, however, i believe in yours the optocouplers were switching the whole battery voltage and then forming the voltage divider. here its done the same but before the optos. i still really think that isolation for the mcu isn't required since the optos will break the circuit and provide isolation between the mcu and battery 2. (this only works if you don't want ADC to measure the voltage of the batteries.)
Forgot to add to schematic but R10 should be replaced with a 12v zener
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