24v starting system on latest SR3 question

[DarioT]

I was working on one of the new 1340 with 24v starting.

has anybody any idea how they deal with isolating the 12 and 24 volt systems from each other.

i have my own theories but thats all.

Also, if they are not connected (which they can't be) then charging the additional battery is a must or it will always be in a state of discharge.

Cheers

Dario

Edited by DarioT on Thursday 28th October 21:11

[splitpin]

I'd assume there's a switchover device that connects the batteries in series simply for starting then reverts to having them in parallel for everything else.

That's a guess, perhaps RadTech will pop in and tell us.

[BertBert]

I'd love to know how it works too.

From what I can see (and from what Simon T described), the 2nd battery does nothing other than join in the starting. Then it get's bumped in series to provide 24v to the starter. All the 12v electrics are done from the first battery.

The "24v charging ecu" deals with the charging of the two batteries so they stay in sync (as it were). It may also deal with the isolation of the two batteries, but I'm not sure about this.

I don't think the batteries work in parallel to provide the normal 12v power.

As I mentioned in my other thread, how do you jump start a 24v SR3?

Bert

[Simon T]

Put in new batteries...

[splitpin]

From what I've read about 24V electrics (like on most trucks and some 'can deal with the arctic' spec 4x4s) like Simon says or tow start.

[DarioT]

Hmmm, very interesting!

they must have sorted out something quite unique.

if you series the batteries and raise the voltage of the DC starting system to 24v, it follows that the the remainder of the electrical system will be isolated from the starting circuit.

it would be more practical to have 24v permanently connected to one side of the starting relay and then from the either or both of the batteries via zenner diodes or just normal blocking diodes connect the 12v side of each battery to a common point (the control circuit take off point)

if the ECU is used to charge it would not be a problem to keep both batteries charged to the same level.

the only other point would be the connection of a slave battery to start the engine when needed. it will likely only support one battery or you would land up putting a 12V across a 24v system.

Dario