split charging system

[v64paul]

hi everyone, i'm new as a member but have been hanging around for a while as it were... i have a 2000 (new shape) diesel tranny as a works van. it has twin batteries in the back configured to give out 12 and 24 volts at two handy jump start points at the back. some nugget has attempted a split charging system but the wiring is fried so it's obviously wrong. has anyone got a wiring diagram so i can fix this? sorry it's a new shape one as i guess a lot of you are a bit anti... if it helps, my other car is also a ford

[Luke]

We're not anti new shape whatever gave you that idea? fred??
Anyway have a browse of this post!!! from a while ago it might have some info thats of use to you!!!

[FredTransit]

Just wouldn't have one myself..............

[v64paul]

cheers guys! as i was a bit relaxed last night... i will clarify. the original battery is in place and fine. the two extra batteries are there to supply power for jump starts and to test lighting and abs systems on 40' trailers and the like. so having them fully charged is a good thing. rifleman's circuit diagram looks o.k. is just that i'm charging two batterys. maybe its a lot to ask of the alt?

[FredTransit]

Our big un has two batteries, no switchover just linked batts, and a regular heavy duty alt. This is one of the options on the SVO list. It's sometimes called the arctic spec.

[bortaf]

Me mate used to charge 3 batterys in bedford rascal with the standard alt (used em to recharge drill batterys) so yours should be up to it but it will be slow to recharge em if they've been used without the engine running, ok if you drive a fair distance between jobs.
All i did on his when i fitted em was to use a split charge relay (like used on tow cars for charging a caravan battery) cost about £7 and as they where seperate from the main vehical system they where only earthed to the chassis and the relay wire was the only live conection to them.
Make sure the alt belt is new and tight or if the batterys are heavly flat the belt will squeel from the drag on the alt trying to charge 2 flat batterys when the engine is idling.
Ther are heavy duty split chargers for heavy use (IE fast drain and recharge cycles like on ambulances) pop in your local council transport depot or ambulance station they've allways been helpfull to me when i was building campers and the like.

You may want to upgrade the alt ,so when/if it goes get one from a model with more leccy toys like a tourneo/exec mini bus (with leccy windows ect) as it should have a higher output than a standard one.
The usuall trick on an early petrol engined van is to fit one from a Ghia car (like a granada or sierra with all the leccy toys) not sure if your engine is used in any cars though?

[madvanman]

if your 2 batteries are wired for 24 volts you will only be able to charge one at a time from your 12volt alternator or switch them to a 12volt configuration for charging.

if you charge 1 at a time you must make sure that niether negative terminal is directly connected to ground on your van,
then switch the positive terminal of the selected battery to the charging circuit and switch the negative terminal of the selected battery to ground.

if you switch to 12v to charge you must disconnect the link between the 'low 12v battery' positive and 'high 12v battery' negative terminals then connect 'high 12v battery' negative to ground and join both positives together and to the charge circuit.

[v64paul]

lots of info ta guys! nah dont think the 2.4 turbo is fitted anywhere else so i will go down the route of charging one at a time. the set up allows me to use the workshop battery charger set at 24 volts but the idea is that i should never be in the workshop long enough... could put the charger in the back and run it off the 240v side of the welder/generator while i go from job to job.... aint found a use like that for the compressor yet though. given all that, my tools a load of spares, a half set of gas bottles, me, the legal limit is very do able on the m6 although stopping takes a bit of planning. another guy at my work has the same set up in a smiley front lwb with a di which mine leaves for dead eventually. thanks again guys and any help i can give in return will be forthcoming.

[madvanman]

you can use a bunch of relays and a 'change over' switch to charge the batteries one at a time from your alternator:


sorry about the size/quality of the images but you should be able to see them ok if you view them with a paint program (all ive got on this pc is ms paint included with windows)