Over charging.

[Rodger]

First a few basic facts: I am a complete dummy regarding electrics.
Our 40 series has HJ60 running gear - all 24v.
It retains the original 40 series wiring loom.
The alternator is a standard 40 series with an external regulator with three wires (+one that goes nowhere).

Over the years we have gone through numerous v/regulators but now, when I last checked, Toyota have only 1 left, so I must address the ongoing problem of over charging.

The set up we have now has a 24v truck voltmeter built in and I have tried to adjust the VR and use the headlights to control the charge and attempt to keep it below 28 on the gauge. This means I constantly have my headlights on and the charge rate is controllable because I giving it sufficient discharge(?). Without using the h/lights the voltmeter acts like a rev counter as the revs increase it goes straight into the red.

For years the 12v take off was from one battery but last year we fitted a dropper and took out that 12v feed converting the second fuse box (another original 40 series one) back to 24v. The dropper works from the cig lighter, has a switch and runs the CB and GPS which we only use off road to get L&L positioning as we are both map freaks. That all works fine.

When Blown80 visited the UK in 2013 he brought a modern replacement set up but it needs a 6 wire set up as per the 60 series and obviously my loom wasn't set up for that.

I have no idea how to address the problem and if you can suggest a solution then please put it in simple terms for me. Thank you

Regards,

Rodger

 

[StarCruiser]

My first thought Rodger is to change the alternator for a 24v one. Almost the same thought is that you say you have a wire 'going nowhere' could this be a voltage sense wire to go to battery + via a fuse or fusible link?

Not sure what wiring you have on your truck in terms of connections or the 6 wire setup you describe. Photos would be more use along with connection diagrams and part numbers (photos of). As I mentioned in the other thread, Mike at Robson and Francis will almost certainly be able to help on this, but do post some pics and more info first.

 

[Towpack]

obviously the existing VR is faulty if it can't keep the voltage within spec. I think you have 3 choices here.

1. Convert the whole system to 12v with new alternator (and possibly battery) plus all the bulbs and other 24v ancillaries. Expensive and a bit of a faff.

2. Replace the existing alternator with a new 24v item with built in VR. I'm not familiar with the under bonnet layout of the 40 series so this may mean fabricating new mounting brackets etc plus fitting new connectors to match if you use one designed for another vehicle but not that difficult.

3. As the existing alternator uses an external VR, just replace the 24v VR with a new one, possibly even one designed for a different alternator which would have to be mounted in it's own housing and connected to the existing alternator with short pigtails.

The 'ideal' fix is probably the first if cost isn't an issue, the third will be the cheapest but will require some work mounting the VR and some work making up some leads and connectors and a metal housing. The second option is probably the one I'd look at first to see what alternator mounting issues there are. JMO

 

[moggy1968]

my voltage indicator was doing the same, acting like a rev counter. It went to an Auto electrician who did end up running a wire back to the fuse board and then off somewhere else when they fitted the voltage regulator (which the previous 2 garages hadn't realised was missing!) However, it's still overcharging, anything from 28-30V.

Now, my cousin has recently been having a lot of trouble with his camper van electrics and in the process of researching that he has found that even a small overcharge kills batteries, so 28V on a 24V system is too much. Should be 26v max

My original alternator was the built in reg type and the new one isn't, so I think the 2 are interchangeable as long as you can find one with a built in reg.

 

[moggy1968]

This is what the wiring to my regulator looked like after the drive back from Italy, clearly, something has to be done!!

 

[Rodger]

Thanks guys, that is a lot to think about.
Couple of points: my alternator is 24v and has the vacuum pump on the back for the servo. It was new a few years back as I was running a HD one and we thought that might be causing the problem. The manuals I have been using for adjusting the setting on the VR are for a FJ40 (petrol) as I have never had a BJ manual but have searched and found one this afternoon on I8Mud, so a bit of reading in there might help. A quick look in this download shows the adjustments to the VR for my type of alternator.
Have attached a scan which shows the two types of external VR and mine is the 3 wire ammeter type. The 6 wire is similar to the 60 series but IG & B are reversed.
I'll have a read of the manual and get back but I appreciate your input.

Many thanks
Rodger

 

[StarCruiser]

There has to be a more modern solid state regulator for this surely?

Hmm, battery charging voltages are given in this article for various batteries.
http://www.chargingchargers.com/tutorials/24-volt-charger.html

Bulk charge into a 12v lead acid 'wet' battery is around 14.4v, hence across 2 batteries will be 28.8v. Irrespective of what the voltmeter in the truck reads, a good multimeter should be used across the battery terminals as voltage at other parts of the system could be different due to losses in the cables.
Once the battery is close to being fully charged (85% from memory) a modern charger will cut back the charging voltage to 13.8v for a 'Float' charge. In the first stages of charging it is important to put a high enough voltage into the battery to get it to accept the charge (begin'gassing') otherwise if this voltage is not reached, it will just sit there taking no charge.

 

[Towpack]

An electro-mechanical voltage regulator. Not seen one of those in a long time. At least they're adjustable/serviceable I suppose, unlike the solid state, throw away stuff.

 

[moggy1968]

Thanks guys, that is a lot to think about.
Couple of points: my alternator is 24v and has the vacuum pump on the back for the servo. It was new a few years back as I was running a HD one and we thought that might be causing the problem. The manuals I have been using for adjusting the setting on the VR are for a FJ40 (petrol) as I have never had a BJ manual but have searched and found one this afternoon on I8Mud, so a bit of reading in there might help. A quick look in this download shows the adjustments to the VR for my type of alternator.
Have attached a scan which shows the two types of external VR and mine is the 3 wire ammeter type. The 6 wire is similar to the 60 series but IG & B are reversed.
I'll have a read of the manual and get back but I appreciate your input.View attachment 138734

View attachment 138735

Many thanks
Rodger

now thats interesting because thats exactly what my after market reg looks like, so if you work out how to reduce the voltage that would be well helpful

 

[moggy1968]

There has to be a more modern solid state regulator for this surely?

Hmm, battery charging voltages are given in this article for various batteries.
http://www.chargingchargers.com/tutorials/24-volt-charger.html

Bulk charge into a 12v lead acid 'wet' battery is around 14.4v, hence across 2 batteries will be 28.8v. Irrespective of what the voltmeter in the truck reads, a good multimeter should be used across the battery terminals as voltage at other parts of the system could be different due to losses in the cables.
Once the battery is close to being fully charged (85% from memory) a modern charger will cut back the charging voltage to 13.8v for a 'Float' charge. In the first stages of charging it is important to put a high enough voltage into the battery to get it to accept the charge (begin'gassing') otherwise if this voltage is not reached, it will just sit there taking no charge.

Hmmnn, it did occur to me to wonder if a problem might be that the battery is continuing to be charged after it is full. The voltage tends to start off about OK, 26-28v but then rises to as high as 30v over time

 

[StarCruiser]

Hmmnn, it did occur to me to wonder if a problem might be that the battery is continuing to be charged after it is full. The voltage tends to start off about OK, 26-28v but then rises to as high as 30v over time

When the load drops away the voltage goes up. The regulator should disconnect before this happens. A solid state one would keep the voltage stable so that the battery rises to almost meet it at which point little current flows. With the regulator functioning as it does it still pours charge in and will of left unchecked, boil the batteries, losing water as steam from the electrolyte and potentially buckling plates.

I cannot imagine things would not be improved with a solid state external regulator.

 

[moggy1968]

When the load drops away the voltage goes up. The regulator should disconnect before this happens. A solid state one would keep the voltage stable so that the battery rises to almost meet it at which point little current flows. With the regulator functioning as it does it still pours charge in and will of left unchecked, boil the batteries, losing water as steam from the electrolyte and potentially buckling plates.

I cannot imagine things would not be improved with a solid state external regulator.

So the regulator is not disconnecting properly?

 

[StarCruiser]

It certainly looks that way, unless it is disconnecting but feeding your voltmeter only. Measuring voltage at the battery will show what it is doing. I suspect your voltmeter isn't directly connected to the battery but to a terminal on the regulator.

 

[moggy1968]

All I know for certain is it managed to destroy a new set of batteries in a week

 

[StarCruiser]

I've sent a question to Mike at Robson and Francis. If anyone's going to know a better solution he will, I would think the best solution would be in alternator with built in regulator but I'll report back what he says.

 

[StarCruiser]

Thanks guys, that is a lot to think about.
Couple of points: my alternator is 24v and has the vacuum pump on the back for the servo. It was new a few years back as I was running a HD one and we thought that might be causing the problem. The manuals I have been using for adjusting the setting on the VR are for a FJ40 (petrol) as I have never had a BJ manual but have searched and found one this afternoon on I8Mud, so a bit of reading in there might help. A quick look in this download shows the adjustments to the VR for my type of alternator.
Have attached a scan which shows the two types of external VR and mine is the 3 wire ammeter type. The 6 wire is similar to the 60 series but IG & B are reversed.

I don't suppose there's any difference in setting up a regulator on a petrol to one on a diesel. A quick look on EBay brings up this 6 terminal one from Oz https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.co.uk/ulk/itm/152789046755 It may be worth messaging the seller to ask if it's solid state or mechanical.

 

[Ben Stratford]

All I know for certain is it managed to destroy a new set of batteries in a week

I have done this twice this year Moggy and just found the near side battery discharged again while fitting new battery cables. Also found a broken connector so have 4 new ones now

 

[Rodger]

The wiring diagram in the newly acquired BJ40 manual does not show the extra wire on the VR and so far I haven't found the adjustments for a 3 wire VR but I do have the adjustment info for the 6 wire (HJ60) VR. It may help both Moggy and Ben and is attached.
On mine (3 wire) I have IG, F & E. From these tests shown below I can only test IG-E but that may get me nearer. Or not. What do you guys think?
It strikes me that we over-charging because the 'adjusting arms' are still in contact when they shouldn't be. I'll search I8Mud to find 3 wire VR adjustment tests.
Hope this helps.

Regards,
Rodger

 

[moggy1968]

I have done

I have done this twice this year Moggy and just found the near side battery discharged again while fitting new battery cables. Also found a broken connector so have 4 new ones now

It's always my nearside battery that goes

 

[moggy1968]

The wiring diagram in the newly acquired BJ40 manual does not show the extra wire on the VR and so far I haven't found the adjustments for a 3 wire VR but I do have the adjustment info for the 6 wire (HJ60) VR. It may help both Moggy and Ben and is attached.
On mine (3 wire) I have IG, F & E. From these tests shown below I can only test IG-E but that may get me nearer. Or not. What do you guys think?
It strikes me that we over-charging because the 'adjusting arms' are still in contact when they shouldn't be. I'll search I8Mud to find 3 wire VR adjustment tests.
Hope this helps.

View attachment 138759
View attachment 138760
View attachment 138761

Regards,
Rodger

Thats really helpful thanks, looks like a pretty heath Robinson way to adjust the voltage but worth a bash. So is it the relay that affects if the voltage continues to charge too mush once the battery is recharged?