What Can Cause Flat Batteries?
Flat batteries can happen any time - usually at the most inconvenient and in completely inappropriate locations.
Question: I have a 2018 Concept Innovation 600 which I have parked up under a carport so solar panel doesn’t work. It is fitted with a BMPRO monitor and a BMPRO BatteryPlus35SR control box. The problem I’m having is that the battery goes flat within 2 to 3 weeks while parked up. The only things that I am aware of that is consuming power is the monitor, controller, radio clock and a small LED ring around the mirror switch. If I turn off the battery on the monitor then all seem to go off except the controller, but battery only lasts for approximately another week. Do you have any idea what could be consuming so much power? (from John Burges)
Answer (David Bayliss): Hi John. Thanks for your question. What you have identified certainly could be a problem if not addressed as it could ruin your next trip when camping away off-grid. Regardless of whether you have your van parked under shaded area or not it sounds like you most likely have an issue with you battery and not the setup. You’re probably not be seeing this issue if the van is parked in the sun as the solar panel will keep a level of charge pushing through to power the small number of loads you mention. However, it is likely that there is not a lot of charge going into the battery anyway as it is either damaged or too old.
Three things to check before heading off to source a replacement battery. Firstly, is it is best to check if there is what is called a ‘parasitic load’ which could be consuming power that you are unaware of. Whilst not a calibrated device — check the screen in your van and turn off the system via the ECO switch — check your manual depending upon which screen version you have installed. Go to the energy management section and as this switch will have disabled all loads – except the monitor (output 1), the power consumption should be less than 1A. If it is greater than this then there is an additional load connected to terminal 1 on the BMPRO BP35SR. Check the output section of the system to ensure only one cable is connected. If not, you have identified what could be part of the problem in that another load is draining power through terminal 1 which is supposed to be dedicated to screen only and preserve your battery.
Second check is to ensure that there are no loads connected directly to the battery that don’t go through the BMPRO system. For example, if you have installed an inverter or some other appliance directly to the battery, the power management system can not see this current drain and as such can not include it in the calculations required to effectively manage your battery charging requirements. Nor can the system turn this load off when you activate the battery isolation button on the screen. If something is connected directly to the terminals, remove it, recharge the battery and see how long it lasts now.
The third check to perform is to disconnect all loads from your battery and to charge the battery with a 12V smart charger separate from the power management system. Once the battery is fully charged leave it for 2–3 weeks and I would expect that from what you have described that the voltage will have dropped back to 12.2V or under then you have a battery that needs to be replaced. If upon checking the battery it has not swelled (vented) than it means that the lead plates inside are damaged in some form. There are several issues that could have caused this. Of course, if your van is relatively new it could just be that you were supplied a below average battery on delivery.
In the event that your battery wiring meets the requirements in the first two tests and holds up on a voltage test than you will need to take it into a caravan repair centre to check out your wiring for further assessment on why the battery is being drained. Most likely your battery is at the end of its life due to age or damage and unable to produce and store the energy due to the lead plates inside being diminished in capacity. For a final sanity check, remove battery safely and a simple impedance test at your local battery store will ratify the above.