Read the voltage from the meter display. Charge your 24 volt winch or thruster battery with up to 200 amps from a 12 volt supply.
Windynation Trakmax Mppt 12 Volt 24 Volt 40 Amp Solar Charge Controller
How to get 24 volts from a 12 volt system. There will be 24 volts about 28 volts with an alternator if two 12 volt batteries are wired together in series. An alternative to this would be to install a 24 volt system but incorporate a charge controller that reduces the voltage to 12 volts whenever necessary. The one being tapped needs more than the other so it will be undercharged while the other will be overcharged. Have both systems installed if your appliances run on 24 volt systems as well. 12 volts from a 24 volt system bjorn is right. Touch the red probe to the positive terminal of the battery and the black probe to the negative terminal.
Connect the positive terminal of one battery to the negative terminal of the other. A reading around 10 to 14 volts comes from a 12 volt battery. If you cannot find the voltage set the digital multimeter to read 24 volts dc. You cant rely on a 24v alternator to fully re charge the battery that is being tapped since the current is split between the batteries. Get 24 volts by connecting to 12 volt batteries in series. If you connect an alternator that has been designed for charging a 12 volt battery to any 24 volt system in an attempt to charge its batteries that alternator will not work because of either of.
The best system to install for most users would be 12 volt since most home appliances run on this voltage. Click picture for details and ordering. Once the charge is delivered the voltage returns to 12. While you can temporarily increase a 12 volt battery to 24 volts by storing a charge and then releasing it the effect is shortlived. The trollbridge2400 will support 24 volt loads up to 500 amps 16 horsepower.