Does a 100 series require 2 batteries to start it?

The T/D 100 series had two starting batteries from the factory. You can use only one if you have the right size (huge) battery. They aren't isolated from each other either.
Cheers
Dave

Boo,i also Believe the two batteries are to start the motor
The F250's are the same, 2 700's & you need to replace both when they Or one fails.


Bob.

Forgot to mention that they are a combination cranking and deep cycle.

It is very common to isolate the batteries on the HDJ100, and crank off a single battery - same setup as this motor has in the 78/79series. Most will increase the size to N70 to cover the cold starts.

The engine preheat comes off the drivers side battery and everything else off the passenger side battery so most people keep the passengers side battery as the cranking battery, and use the drivers side for the auxillary.

The absolute truth is that Toyota put two batteries in for cold climate starting.'

And before you all start I know that doesnt apply here.

However it is probably easier and cheaper to do them all the same.

They are connected pos to pos to give 12 volts so there is no isolation switch.

The original two if you care to look are only around 400CCA even though they are about the same size a an N70.

I split mine and replaced thim with two Yaeusu hybrids of eqiv size to N70.

To do this you have to alter a few things but is quite easy

One is absolutely adequate to start it on all but perhaps sub zero temps.

However I put in a relay that hooks them together as original just to start it.

If you also look at their wiring looms they are identical in almost all models as for the reasons above.
Some other country models differ as I got two heated seat switches out of an NZ Sahara and the wiring was different under the console.

simply put in a smart solenoid extend the positive battery leads to suit. you wont have to touch the alt wiring. or put a cole hersee(m750) switch in

If this truck is an import it could well be a two battery installation with the truck all running at 12 volt but uses a special relay for 24 volt start
Most L/Cs in NZ are like this
Ray

The state of the art Sterling ProSplitR 12V 120A 3 outlet zero volt drop manager will eliminate most problems.
The alternator power goes to it and then feeds each battery under the bonnet independently and with safety and you still have a third outlet to run to the rear for a camper which is also independently supplied and monitored.

Distributes the most power to the battery that needs it.

Isolates a battery bank when there is an attempt to backfeed the power from the full battery to a more demanding battery.

Isolates all full battery bank outputs except the main load battery in the event of a massive load on any other battery bank.

Isolates the alternator from all batteries in the event of a failure of the alternators own regulator.This prevents the batteries from boiling.

Isolates any battery that tries to feed back a high voltage from a different source.IE: if there was a defective battery charger on one battery bank trying to feed into another battery bank then the unit would disconnect the battery bank to save the others.

LED display shows which channels are in use and which are not.

Overload design EG the model rated at 180A is actually continuos rated at 240A with overload in excess of 2000Amps

Fail-safe , in the event of unit failure the engine start battery and the alternater remain connected ensuring the safe running of the boat or vehicle. Prioritizes the engine start battery over all other battery bank outputs.

Ian