Morning all.

I have a Jurgens Palma. For the last couple of years I have disconnected the 105Amp battery from the built-charger and connected it to a smart charger while the van is not in use. Because of covid this has been about 18 months now. I have however still kept the van connected to the 220v supply to run the charger. Yesterday I read on an English site that if the built-in charger runs without the resistance of the battery it will damage the charger.

Does anyone know if this information is correct?

Please answer in English if you know as my Afrikaans is not good enough to understand technical stuff.

Thanks

Morning. I cannot understand the reason for keeping the charger on the 220V supply. You do charge your battery separately by way of a smart charger (good for you!) but why the rest? Unless you wanted to keep your refrigerator and/or lights on? If that is the case I will hazard a guess in saying that, since you do use the charger (for running the said appliances) there should be no harm. 

It may not be a similar situation, but, in my workshop I use a car radio to keep me company. This is connected to a charger to supply the required 12 Volts (considering it is a car radio). When I am not in the garage - sometimes, due to camping holidays for quite some long periods - the charger cannot "dispose" of the charge (due to the radio not being switched on) but still stays connected. This has been my set-up for the last 40 odd years (!!), and the charger (little as it is) has never failed.

Nico wrote:

Morning. I cannot understand the reason for keeping the charger on the 220V supply. You do charge your battery separately by way of a smart charger (good for you!) but why the rest? Unless you wanted to keep your refrigerator and/or lights on? If that is the case I will hazard a guess in saying that, since you do use the charger (for running the said appliances) there should be no harm. 

It may not be a similar situation, but, in my workshop I use a car radio to keep me company. This is connected to a charger to supply the required 12 Volts (considering it is a car radio). When I am not in the garage - sometimes, due to camping holidays for quite some long periods - the charger cannot "dispose" of the charge (due to the radio not being switched on) but still stays connected. This has been my set-up for the last 40 odd years (!!), and the charger (little as it is) has never failed.

 

the reason is the 105 battery is too big and heavy for me to get out from under the bunk( I am 68 years old) so the smart charger is plugged into one of the caravan's 220v plugs.

I still reckon that the build-in charger will suffer no harm, using my garage charger as above as reference. 

Nico wrote:

I still reckon that the build-in charger will suffer no harm, using my garage charger as above as reference. 

i tend to agree but every comment on the english FB site said the charger would be damaged without the battery resistance.

thanks 

As Nico indicated the power supply type of charger fitted will not be damaged. Do as you do to ensure the battery stays fully charged. Even the standard charger will not over charge unless faulty. 

One lesson here. Social media causes every other guy to be very clever behind a keyboard. Never a loss for those writing comments  if it turns out bad advice. 

In my opinion it won’t be damaged without a load (the battery in this case). I would however (and this what I have done) run a separate extension lead through the window and leave the caravan off 220v. This way the electronics in the caravan are off and this is safer and gives them a longer life.

Also your caravan charger can only float the battery which is ~80% charged from flat. With a smart charger you can fully charge the battery to 14.2-14.8v. A smart charger will automatically boost charge your battery when it needs it.

I have just spoken to my old friend Leon Le Grange. He is also an Electronic Engineer and Masters Diploma Technologist, who use to work for Telkom with me. The return of camping after the COVID-19 ban gave him lots of Apollo & Hercules charger repair work. Campers did not keep their caravan batteries maintained and then simply, after 18 months, switched on the mains and the built in charger. Some batteries had failed (short circuit cells) and burnt out the charger in the process. $$$$$

1) Regarding whether you need to disconnect the battery when parked for a long time, YES!!. There are static/parasitic currents that will drain the battery completely within a month, irreversibly damaging it.

2) Regarding keep the battery on float charge (13.9V), YES!!. Fully charging it (~14.4V) once a month is also a good idea.

3) Regarding whether you must disconnect the battery from the Apollo 10/20 or Hercules when you charge it with an external intelligent charger, NO!!. (if you did (1) above then this is irrelevant.) The Field Effect Transistor in the output of the built in charger can take a reverse voltage of ~110V. It turns off when the external volts exceeds 13.9V.

To simplify the external charging, leave the mains connected to the caravan and therefore the Apollo DB board. Then you can plug your charger into a spare 220V socket on the box. On the Apollo remove the charger 4A screw in glass fuse so that the built in Apollo charger is off. If you want to isolate the 12V caravan battery from the caravan you can remove the 20A blade (car) Battery fuse.

I hope this helps you save lots.

Baie Leersaam

Dankie Swanie.

Sorry, I stated 110V max input voltage (wrong FET), the Vdss (Voltage drain-to-source) Breakdown voltage of the Apollo charger output MOSFET, IRFZ44n is 55 volts. So you can connect up to about 55V to the output of the Apollo 10/20 before there could be any possibility of any damage. Like a switch that is open up to a maximum break down voltage of 55 Volts across it. That is if the gate voltage, Vgs, is kept at zero, which is done by a 6.8V zener diode when the battery voltage is above 13.9V. So, the FET is open (off) above 13.9V (with a voltage divider)..When the battery is being float charged the output FET toggles on/off keeping the battery at 13.9V. The input to the FET is at a constant 13.9V.

Just if you would have liked to know the reasoning behind point three above. :):):)

Net Å„ bietjie terugvoer oor my ondervinding met CTEK. Ek het Å„ CTEK MXS 5. Na 10 jaar pak hy toe tot my verbasing op. Hy wys net “error” en laai nie. Ek koop toe Å„ nuwe een en vat die stukkende een na ODW en hulle stuur hom na CTEK vir reparasie. CTEK stuur vir my Å„ nuwe een.

mulderpm wrote:

Net Å„ bietjie terugvoer oor my ondervinding met CTEK. Ek het Å„ CTEK MXS 5. Na 10 jaar pak hy toe tot my verbasing op. Hy wys net “error” en laai nie. Ek koop toe Å„ nuwe een en vat die stukkende een na ODW en hulle stuur hom na CTEK vir reparasie. CTEK stuur vir my Å„ nuwe een.

Dit is nou 'n gelukkie.

mulderpm wrote:

I have just spoken to my old friend Leon Le Grange. He is also an Electronic Engineer and Masters Diploma Technologist, who use to work for Telkom with me. The return of camping after the COVID-19 ban gave him lots of Apollo & Hercules charger repair work. Campers did not keep their caravan batteries maintained and then simply, after 18 months, switched on the mains and the built in charger. Some batteries had failed (short circuit cells) and burnt out the charger in the process. $$$$$

1) Regarding whether you need to disconnect the battery when parked for a long time, YES!!. There are static/parasitic currents that will drain the battery completely within a month, irreversibly damaging it.

2) Regarding keep the battery on float charge (13.9V), YES!!. Fully charging it (~14.4V) once a month is also a good idea.

3) Regarding whether you must disconnect the battery from the Apollo 10/20 or Hercules when you charge it with an external intelligent charger, NO!!. (if you did (1) above then this is irrelevant.) The Field Effect Transistor in the output of the built in charger can take a reverse voltage of ~110V. It turns off when the external volts exceeds 13.9V.

To simplify the external charging, leave the mains connected to the caravan and therefore the Apollo DB board. Then you can plug your charger into a spare 220V socket on the box. On the Apollo remove the charger 4A screw in glass fuse so that the built in Apollo charger is off. If you want to isolate the 12V caravan battery from the caravan you can remove the 20A blade (car) Battery fuse.

I hope this helps you save lots.

 

Hi Paul,

Many thanks for your explanation of the Apollo 10 functions in your 2 very technical posts on this thread, I think you've helped give me insight into solving an issue I am dealing with at the moment with an Apollo 10 unit in our Jurgens Classique 2006. Could I please pick your brain a bit? (I will try add some pics below to help guide the process)

The caravan has space for a battery in the nose cone and I understand that:

(1) the Apollo 10 receives a 12V line input from the two wires coming off this (external) battery and;

(2) the Apollo 10 charges back into the battery over the same 2 wires.

... question, are these 2 statements correct? Or does the outgoing charger circuit use 2 different wires coming out of the Apollo 10 that connect along the way to the 2 external battery wires?

I have now put movers onto the caravan and decided to go with a new 105 AH deep cycle battery instead of the original 80 AH battery that I found in the nose cone when I bought it. An issue is that the new 105 AH battery is too tall to fit in the nose cone (its width & length fit fine, but the cover for the battery compartment now cannot close due to the height of the new battery) and so the 105 AH battery has been positioned inside the caravan, under the seat, which is over the axle, in the compartment where the Apollo 10 unit sits.

I would rather not have 2 batteries to deal with for reasons of added expense and the hassle of having to insert & remove them before / after each trip, especially as we keep it in storage and I would need to be transporting batteries to & from home each time. Hence I would like to see if I can use the 105 AH battery inside the caravan to also run the caravan 12V line.

To facilitate this I am working with 2 ideas:

(Idea 1) Use the existing battery wires

• Go to the nose cone, remove the connectors off the two battery wires (I'm calling these the 'external' battery wires) and pull the external wires back inside the caravan. Then, inside the caravan, put on battery connectors to these 2 wires and connect the two external wires onto the battery.
• This sounds simplest in concept as I would not need to do anything further with the electrics, it should just work.

(Idea 2) Bypass the existing battery wires and connect the inside battery to the Apollo 10

• Having now crawled under the caravan and inspected the cabling coming into the caravan, my view is that pulling the external battery wires back inside looks like a schlepp and, if I later decide to sell the caravan, I would need to undo the process and I'd like to avoid that.
• Hence I'm thinking to leave the two external battery wires in the nose cone, ensuring that they do not touch each other or short to the chassis in any way. And then intercept those two wires as they come into the 12V connector on the side of the Apollo 10 unit so that the new battery feeds into the Apollo 10 instead of the two external battery wires. Hence, the existing 2 external wires would come inside the caravan and come to a dead stop, not connecting further along into the Apollo 10.
• Regarding the 12V connector on the side of the Apollo 10 unit (pics below hopefully):
  • there is a white, female, plastic connector attached to the sidewall of the Apollo 10 with 8 pins showing and;
  • a white, male, plastic connector which plugs into the female which has 8 wires coming into the back of it, 2 of which are presumably the 2 external battery wires where they come into the caravan.
• To remove the two existing external battery wires from the equation I have bought a new set of male / female connectors and am thinking to use the new connectors with several short lengths of wire (maybe 10 cm long) to form a straight-through "bridging cable" between the original male / female connectors. Hence, if all 8 wires were to go "straight through", nothing changes electrically, I just have the original male/female connectors now separated by 10 cm of extra wire length.
• However, if 6 of the 8 wires go straight through and the 2 wires coming from the external battery do not go straight through but, instead, stop at the male connector, and I then run 2 wires from the inside battery into the Apollo 10's female connector at those 2 pins that do not have a straight-through wire, I am hoping that the Apollo 10 then knows no difference. i.e. it is still getting 12V line-in from a battery on those two pins and would presumably be trying to charge the battery back the way (either along these 2 wires or 2 other wires?).

... question, idea 2 sound feasible electrically?

... question, am I right that the 2 external battery wires receive charging back down these same two wires or is there an additional pin or two that provides the charging voltage and, somewhere along the way, the 2 external battery wires are connected to the outgoing charging voltage wires? I saw a post saying that someone measured voltages on the pins coming out of the Apollo 10 and pins 1, 3 & 4 all had 13.7V on them, so perhaps the incoming 12V line and outgoing charging line are indeed on different wires / pins.

Additionally, regarding charging the new battery

My understanding is that the charger in the Apollo 10 is not a "smart charger" and that deep cycle batteries do better when connected to a smart charger. I have a smart charger and am thinking to use it inside the caravan, plugged into one of the 220V 3-pin outputs of the Apollo 10 while we camp. (From your post I understand that I should disconnect the inside battery when we're not using the caravan, bring it home and charge it with the smart charger.)

From your posts I understand that if the Apollo 10's charger is connected to the battery at the same time as an external smart charger, there will not be any conflict electrically and the 105 AH battery will benefit from the smart charger's capabilities.

... question, is this correct?

As an additional measure, you suggest that this arrangement could better work if the 4A fuse that is inline for the charger circuit on the Apollo 10 is removed, that way there is no charging of the inside battery taking place from the Apollo 10, only from the smart charger.

... question, is this correct?

So, bringing the above 2 sections together, the plan would be to:

• Isolate the existing external battery connectors in the nose cone so that they do not touch each other or short anywhere.
• Build myself a "bridging cable" that allows 6 of the incoming wires to go straight through.
• Connect the new inside battery into the 2 pins on the Apollo 10's female connector to replace the 12V line-in from the external battery with the 12V source of the internal battery.
• Remove the 4A fuse to disable any external charging.
• Charge the inside battery using a smart charger that runs off one of the Apollo 10's 220V output lines.

... question, would this work do you think?

I know this has been a long post, hope you've stayed with it and I have explained the situation correctly and in enough detail to help you understand what I'm thinking about!

Advice appreciated,

Many thanks,

Jeremy.

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Pic 1: 8-pin female connector attached to side of the Apollo 10 unit (on the lower left) and 8-pin male connector (on the upper right) that has 8 cables coming into / out of the caravan.

Pic 2: The 8 cables coming into / out of the caravan and into the back of the male connector