Club 80-90 Forums

isaune wrote: I must admit I was assuming it was simply a case of joining positive to positive to positive and negative to negative to negative with the battery nearest the heater to connect to that and the existing leisure battery to be connected (as now) to the split charge relay?

But from your warning, I am guessing it is not that simple???

You are correct, and yes it is that simple

It's just that one needs to be a bit cautious when dealing with these sort of battery powers

The advice posted after you wrote the above is all good, though as mentioned, that article may be a bit ott in some respects for a camper van. Just make sure the linking wires are capable of handling say 50 amps and are carefully and neatly installed. Don't forget in line fuses on the charging wires and the output wires. Use those HD blade fuses with thick wire "tails" on them. You can pick them up from any decent motor accessory shop. Install them close to the battery(s). You can't have too many fuses ! Those white terminal connectors (like these = HERE) are fine as long as they are of a suitable size and carefully used. Tip = bare the wire end just enough to go 50% into the connector with none visible outside the connector, then fold the bare bit back over the plastic and then insert the wire into the connector with the plastic side facing the screw. This makes a good strong connection and as long as no bits of bare wire can be seen, is very safe.

Thanks everyone for help with this.

Oldie - here is a photo of the top of the heater.

Does that allow you to deduce what model it is and if it is easy to step up a 12 volt battery to run it?

If so, what do I need to buy and how do I fit it?

Many thanks

Ian

isaune wrote:Oldie - here is a photo of the top of the heater.

Does that allow you to deduce what model it is and if it is easy to step up a 12 volt battery to run it?

Definitely a 24v Eberspacher D1LC

Made before March 1995. I am the bringer of bad news:

20 Amps startup for 12v model, 11.25 Amps for 24v one so unfortunately you have virtually the only model that cannot be run via a cheap step up voltage converter! To get a step up for that power you would have to pay around £70 which isn't worth it.

The easiest way that I can see to charge them from the engine is to use a 10 Amp step up converter to 26v from a split charge relay. The drawbacks of doing this will be that if the batteries are run very flat you will blow its fuse as it will request more than 10A from the alternator. This still would leave you without a charging means for when you are on hookup.

Which brings me to the second alternative - use a normal 24v mains battery charger that is run from a suitably rated 12v to 230v ac inverter connected to a split charge relay with the bonus that you could then unplug the charger from the inverter whilst on hookup to plug into your hookup mains socket.

Over to others to see if they can come up with anything else!

Oldiebut goodie wrote:Made before March 1995. I am the bringer of bad news:

20 Amps startup for 12v model, 11.25 Amps for 24v one so unfortunately you have virtually the only model that cannot be run via a cheap step up voltage converter! To get a step up for that power you would have to pay around £70 which isn't worth it.

The easiest way that I can see to charge them from the engine is to use a 10 Amp step up converter to 26v from a split charge relay. The drawbacks of doing this will be that if the batteries are run very flat you will blow its fuse as it will request more than 10A from the alternator. This still would leave you without a charging means for when you are on hookup.

Which brings me to the second alternative - use a normal 24v mains battery charger that is run from a suitably rated 12v to 230v ac inverter connected to a split charge relay with the bonus that you could then unplug the charger from the inverter whilst on hookup to plug into your hookup mains socket.

Over to others to see if they can come up with anything else!

Oh that's a shame, Oldie. I had finally come round to your way of thinking as well!!

I now think I will revert to plan a which was to:-

1) disconnect the heater batteries from the heater
2) connect them in parallel to the leisure battery (3 x 85AH)

This will mean:-

1) they all get a workout when not hooked up
2) they all get charged simultaneously via the alternator (when mobile) or via my charger when hooked up

And the only downside is the faffing around required to reconnect the heater when needed. However, as stated earlier, this won't happen often. Only on the coldest of non hooked up nights.

Cheers chaps

Ian

Just one final question, chaps.

Once I have my heater disconnected and my 3 batteries fully charged and connected in parallel to the switch relay circuit, I just want to check for sure where to attach my charger cables.

I am assuming I can attach the charger to any of the 3 batteries - whichever is most convenient - and they will all get charged and maintained. Is that right?

BTW, I am going to use the arrangement shown in the earlier linked article - not the complicated "best practice" one - but the simpler one taking the positive feed from the battery at one end and the negative feed from the battery at the other end.

I doubt this affects which terminals to attach the charger to but thought I would mention it just in case.

Thanks Chaps

Ian

isaune wrote:I am assuming I can attach the charger to any of the 3 batteries - whichever is most convenient - and they will all get charged and maintained. Is that right?

Yes that is right

(because they will be connected in parallel, they behave as if they were all just one big battery).