Negative to negative and positive to positive. You can parallel these batteries but there will be some mismatch and they wont share the load equally.
9v Battery The Nine Volt Battery For Fetal Doppler Babysonic
9v battery in parallel. So if my calcs are right the resistor for each of the il604s parallel with each other should be 50. Two 6 volt 45 ah batteries wired in parallel are capable of providing 6 volt 9 amp hours 45 ah 45 ah. But these arent rechargables so it would partly work but mostly be a waste. Connecting multiple 9v batteries in parallel is fine for the most part but you would need to replace them all at the same time. Begingroup btw my ultimate goal is to have the 9v battery power three leds. You can connect your load to one of the batteries and it will drain both equally.
One 9v battery will give you somewhere between 120 and 200 hours of illumination with the simplest circuit a series resistor. With a good switching voltage converter circuit you should be able to get more than 600 hours. If you have one that is partly drained connected to a new one then the new one will drain trying to charge the old one. Paralleling batteries can be done if they are both new and equal type. The 2nd config is 4 parallel connections at each battery end also 2 rows of 4 batteries each row connected in series and of course the 3rd image is 3 parallel connections with 3 batteries connected across their and terminals and a single row of serial connected batteries to make 48v. As it is now your power supply is only 56 efficient.
Forward voltage is 30 36 volts to be wired in parallel the third will be a blue led 34 38v 20ma in series with the parallel circuit of the il604s. You should be able to get that to about 90. Two are microtivity il604 5mm rgb slow rotating led. To join batteries in parallel use a jumper wire to connect both the positive terminals and another jumper wire to connect both the negative terminals of both batteries to each other. A much better solution is to use a buck switcher instead of the 7805. The basic concept is that when connecting in parallel you add the amp hour ratings of the batteries together but the voltage remains the same.
Paralleling is a way to get more currentby paralleling them you are making. But as a rule paralleling batteries is not good because you cannot control the above requirement. Unlike wiring batteries in series when batteries are wired in parallel the voltage does not increase the output voltage is the average voltage of all batteries in the circuit. For example if a 3v and a 9v battery were wired in parallel the output voltage would be 6v 93 divided by 2 however the current will be total amperage of all batteries in the circuit minus any losses.