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Need new batteries? Going from 12V to 18V or 6V to 12V? Wiring Questions?
I’ve done quite a bit of reading on this in an informative thread on the old forum, but it stopped just short of what I’m looking for. I haven’t had any luck finding the same info here.

Can anyone help with a schematic for switching between two 12v batteries in parallel and series with a DPDT relay? Also, can a latching switch be used to activate the relay coil or does it have to be the momentary sort? ... OPIC_ID=48

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By wired
Here is a link to a thread with diagrams you could use. It's for an 18v turbo setup. You would just use your 12v batteries to get the 24v you're looking for. you will need to make sure you use a relay rated for the high current draw( I recommend a 60amp or higher but you could start with a 40amp). You will need to use a latching type switch vs a momentary switch unless you want to use the circuit like a turbo function.
To make things more difficult (apparently) I added a master power switch. I think I finally have all the wiring right, but I’m having an issue with one of the SPST relays (the one connected to Battery 1, below) switching off when I flip the switch for the DPDT relay that changes the circuit from parallel to series. Hoping someone can help.
354B1149-056A-4BA4-94FF-8F89DEFCBEAD.jpeg (2.02 MiB) Viewed 259 times
Thanks in advance.
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Maybe I'm missing something but why the regulator? If you're only connected to Battery 2's + and -, you will always have 12V regardless.

Your battery 1 relay is switching off because you're pulling off battery 1 ground. Pull all from battery 2 ground.

Here's my vision of your diagram. All relay grounds pull from battery 2. No regulator.
87a on each relay can be used as a +12 IN if you're planning on charge ports (assuming you use SPDT relays there)
2019-05-02 14_06_28-TinyCad - [tCad1].png
2019-05-02 14_06_28-TinyCad - [tCad1].png (9.97 KiB) Viewed 252 times
THANK YOU. I’m looking forward to making the correction(s) and updating.

I guess with my previous trial and error (sparks and smoke) I had it in my head that the switches were getting 24v and just wanted to be safe... thus, the regulator.

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