Hobby 750 Charging problems

[Anonymous]

<span style=”color: #000000; font-family: Calibri;”>I have been reading with interest about charging issues with the Toptron charger.</span>

<span style=”color: #000000; font-family: Calibri;”>I have a 2001 with said unit and need some help. The Toptron unit failed about 3 years ago and I sent it to Leisure Electronics who repaired it at a very reasonable price.</span>

<span style=”color: #000000; font-family: Calibri;”>For the last 2 years it has behaved and worked properly but has now failed again. When I connect to the mains the unit starts to charge and the LED above the door is RED, it may go to Orange but within half an hour a relay in the Toptron unit will start to chatter and the LED goes to Flashing RED and the ammeter shoots up to 15+ amps.</span>

<span style=”color: #000000; font-family: Calibri;”>I have taken advice on this and told it could be the batteries so I have checked the two 105 amp hour batteries individually and put them on a separate charger to recondition them. At rest they sit at 13 volts which is enough (12.7v) to make the Totron unit work.</span>

<span style=”color: #000000; font-family: Calibri;”>If I switch the Toptron unit off I can still use the 12v lighting, pump, toilet etc. and have to rely on the Solar panel to keep the batteries charged. If I remove the Toptron unit to send it away the Motorhome is just a glorified van and I can’t use it.</span>

<span style=”color: #000000; font-family: Calibri;”>I would really like a proper wiring diagram for the Hobby 750 and not just the one in the Operating Instruction Book. Can any one help?</span>

<span style=”color: #000000; font-family: Calibri;”>Also has anyone replaced the Toptron unit for something else to work with the Control panel above the door or the Toptron Unit and Control Panel together.</span>

<span style=”color: #000000; font-family: Calibri;”>I love the motorhome but this issue is starting to get me down. Advice on any of the issues mentioned above would be much appreciated.</span>

<span style=”color: #000000; font-family: Calibri;”>Thanks Martin.</span>

Topic

[David Lawson]

Hello again Martin,
Yes an (your) alarm / immobiliser will flatten the vehicle / engine battery over a few weeks if not ‘float’ charged.
I am surprised that your solar system is not compensating for this expected drain whilst your assumed faulty battery charger is not.
There are ‘add on’ modules available such as Battery Master or Battery Mate which will transfer any excess solar charge to an engine battery once a leisure battery(s) is considered saturated (charged). Trust me, no such ‘add on’ module is necessary in any type / year Hobby if the installed solar system is wired and connected correctly.
To save any unnecessary time and expense, do remove both batteries (expect to drop the contents of the boiler on doing so) and attempt to recondition them individually.
I repeat, it is impossible to read (achieve) any more than 12.7 volts terminal voltage, 24 hours after a period of rest from a charged a lead acid battery.
As explained in my previous reply, the vehicle engine battery only receives a trickle charge once the leisure battery(s) are satisfied (saturated), when the green light is on at the control panel. This is a one time (one shot) process. If the power supply, normally via the hook up is interrupted, only for a second, the process starts again from scratch. Albeit, after a few seconds interruption, it would be shown as a short period of initial red, followed by another longer period of amber, then back to green on the control panel LED once the charger realises where it is at in the process. Only then does the engine battery receive a trickle charge.
In your case, ignoring any problem with the Toptron charger, your solar panel should be keeping your engine battery charged.
Your type of Toptron charger needs to see a healthy leisure battery(s) before it can get to the end of that process.

[Anonymous]

Thank you for that information David.

I did take the batteries off one at a time and recondition them in the garage. I checked the voyages on the batteries once I had conditioned/charged them and they were about 13.6v I then left them over night and they had dropped to 13v.

So yes they could have had it and I now need to replace them.

One other thing is I thought that the charge should also keep the Vehicle battery charged whilst on mains but this is not the case with my van. I have fitted/replaced with a brand new one and after about 3 weeks the battery is totally flat. The only current draw is the alarm/immobiliser.

Martin.

[David Lawson]

Hello Martin,
I would be tempted to agree with the diagnosis that the two batteries are the problem.
I suspect that the 13 volts that you are seeing at the batteries is from the solar panel.
Best advice is to recondition the batteries again OFF THE VEHICLE but do remember to disconnect the solar panel input to the regulator before disconnecting the batteries. It is possible to damage the solar regulator with the solar panel only connected and no battery as a load. Reconnect the solar panel input to the regulator last.
Having reconditioned the batteries OFF THE VEHICLE leave them at least 24 hours at rest.
It is impossible to read 13 volts at rest after 24 hours.
If the batteries are good you should read 12.7 volts at rest after 24 hours.
Slightly less, but no less than 12.6 (12.5 minimum) volts should be OK.
Do bear in mind that 11.7 volts is considered totally flat for a lead acid battery.
If you need to replace the batteries, do try to purchase ‘maintenance possible’ batteries.
There is no such thing as a maintenance free lead acid battery. If a lead acid battery is charged correctly, it will at some stage in the charging process ‘gas’ which will evaporate some of the fluid. This fluid loss needs to be replenished about twice per year, more often in a hotter climate.
Maintenance possible batteries tend to be cheaper and if looked after and topped up as required will give a much longer service life.
Why not substitue the engine battery for a couple of days. The charger can not harm the engine battery, it is charged by the same charger all the time the green light is on at the control panel.

[Author]

Replies