Jump to content

Vehicle Battery charging


Guest Nick

Recommended Posts

I own a compass castaway Motorhome built on a Peugeot Boxer. I believed that the inbuilt battery charger (cbe switch mode battery charger) charged not only the leisure battery but also the vehicle battery however I am now not so sure as the vehicle battery is flat (vehicle been standing idle for three/four weeks). Does anyone out there know the answer as I cannot find it in any of the paperwork supplied with the Motorhome? If the vehicle battery is not charged by the charger I now need to charge the vehicle battery. Do I have to disconnect both the terminals from the vehicle before connecting the charger as one of them is very hard to reach? Help please.
Link to comment
Share on other sites

Nick, It is not common practice for the switched mode power supply provided to float charge the leisure battery by the vehicle converter to also charge the starter battery. What is common is for the vehicle alarm system and vehicle clock to be run from the starter battery. This combination gives the scenario you describe. Loss of charge due to the alarm system and clock is normal over a period of time. Batteries also have an internal amount of self discharge and this gets worse with age. Both the vehicle and the van batteries have their negative pole connected to the vehicle chassis. Without this the vehicle alternator could not charge both via the split charging relay. I have fitted a pair of blade type fuse holders in a position that I can see every time I enter the vehicle via the driver’s door, in the foot well. One fuse holder has no wires attached. The other fuse holder is connected between the positive terminals of the starter and leisure batteries and is clearly marked with white paint. When the vehicle is laid up during the winter I connect it to a mains hook up overnight once a month and fit the 10 amp fuse in the wired fuse holder. This enables to on-board stabilised charger unit to top up both batteries. During the summer and all other times the fuse is moved to the un-wired “park” position. Should I forget to move the fuse to the “park” position and start the engine, the fuse will blow. So carry a few spares! At least this ensures that you don’t flatten both batteries by leaving your TV running overnight! Don’t forget, the bridging fuse is intended to be used as a bridge ONLY during winter lay-up so that when you connect your van to the mains hookup once a month you can fit the bridge and top up both batteries. Otherwise place the fuse in the unconnected PARK position. If you have a reasonably sized solar panel which charges your leisure battery then you shouldn,t need the mains hookup! Good luck Clive
Link to comment
Share on other sites

Clive thanks for your help todate. Not being the most technical person in the world do you know where I can get a drawing of wiring conections you refer to? For now I need to charge the battery, can I conect a battery charger to the vehicle battery without disconecting the other wires ect from the battery terminals? Nick.
Link to comment
Share on other sites

Hi Clive are you trying to post a reply to my second question? If so your reply is not coming through all I am receiving lots of emails from MMM telling me a reply to my question has been received! Regards Nick
Link to comment
Share on other sites

Guest Derek Uzzell
Nick: My 2005 Hobby has a CBE electrical system with a PC-100HB.T control panel, DS-300HB distribution box and CB 516 switch-mode battery-charger. This is a modular system normally sold as a complete kit and, because it's very straightforward to install, many motorhome converters now use it. The documentation that relates to it says: "Car Battery Recharging: When the battery charger is charging, an electronic device allows a recharging (max 2A) of the car battery. The system gives priority to the leisure battery." So, if your motorhome's electrical system is the same as mine, it seems that, once your leisure battery has reached a fully charged state, a small charge of up to 2A will be sent to the vehicle (car) battery to keep it topped up. If it turns out that your Castaway's system doesn't support vehicle-battery charging via your battery charger, then you can either use Clive's idea or fit a "Battery-Master" unit that does much the same job but is fit-and-forget (but also a whole lot more expensive). It's recommended that a battery be disconnected from the vehicle before a separate battery charger is used. Personally, I've never done this and never had any resulting problems, but perhaps I've been lucky. You are going to have to decide between following best advice and avoiding any risk, or convenience and accepting the (small) possibility there will be an adverse effect.
Link to comment
Share on other sites

Sorry about the hiccups! It was Ameretto! The web address I got out eventually should give a picture of the simple circuit of the bridging fuse. Simple and little to go wrong. I believe the old advice of always disconnecting a battery from the vehicle before connecting to an external charger dates back to the days when cheap of the peg chargers had no regulation, just a transformer and in those days a selenium rectifier. Today most half reasonable chargers do have a maximum current limiting feature and a maximum voltage limiting feature, very much like that of the vehicles alternator. Hence like Derek I haven't disconnected a vehicle battery during charging for years.(as I know what the charger is) My adage is that I prefer things simple enough for ME to sort out on site wherever we may be on holiday. KISS aproach! Good luck C.
Link to comment
Share on other sites

Hi Nick I have had this problem & conatcted our vehicle supplier - in their models much depends on 1 The model of the vehcle 2 The charge controller used, both make and model With some charge controllers there is a facilitu for connecting so that you can charge the main battery via the in built charger As far as solar panels (we are in the process of arranging for one to be fitted) you can get a device that allows chargeing of the vehicle battery (forget what they call it) without this device you can only charge the leisure battery Chargeing the vehicle battery via another charger - It is ADVISEABLE to disconnect the battery terminals before connecting the charger - Many people do not BUT ---------- You can blow some electronic devices Remove the battery cell tops before chargeing and remember Batteries give off Hydrogen gas when chargeing NO NAKED FLAMES or SPARKS Switch off the charger BEFORE disconnecting after chargeing
Link to comment
Share on other sites

I would pose just one question, If one has a regulated charger that applies the same charging regime as the vehicle alternator why is it not necessary to disconnect the vehicle electronics and remove the cell caps when the engine is running? The advice about naked flames is correct. If the charging system is non regulated and pushes the battery voltage above 14 volts then gassing will be much increased as more of the charging current splits the water content of the electrolyts into its two component parts. Hydrogen and Oxygen. What does concern me are motorhomes with modified charging regimes that are normally only used for charging traction duty batteries which are disconnected during charging. These DO push the voltage up above 14 volts or even above 15 volts in order to get the very maximum of energy into the battery. These systems do have the capability of damaging electronic devices that may still be connected. In normal Traction applications facilities are also in place to simply top up the gassed off water with various "Autofill" systems which includes plastic plumbing and float level stop valves. Its is good advice to make sure a stand alone charger is turned OFF when the leads are connected or disconnected. But having said that some modern traction chargers for Fork Lift Trucks are specifically designed to be left turned ON. The charger senses the presense of the battery voltage then automatically "fires up". Its also OK to un-plug the charger from the battery mid charge. It knows that the battery is disconnected automatically and automatically closes down. "Oportunity Charging" is the buzz word for this. Things have progressed a lot over the last 42 years I have been in this business! C.
Link to comment
Share on other sites

Hi all. Thank you to every body that replied. RAC been out fiddled with battery terminals and all is well (it was the positive connection that was the problem and I could not reach it) still do not know if the in-house charger charges the vehicle battery and will be trying to find this out, maybe Compass will be able to help! I will now be able to go away for Christmas and the New Year. Once more thank for all your suggestions. Wishing you all a happy Christmas and a successful New Year. Nick
Link to comment
Share on other sites

Guest Brian Ramsden
One way to find out , if you have got a volt meter, is to connect the meter to the vehicle battery terminals, hook up the 'van to the mains with the leisure battery charger working, then see if the meter reading changes when the mains is switched on and off. If there is any reaction, the charger is connected to the vehicle battery. Brian
Link to comment
Share on other sites

To stop all the "knowlegeable?//" from digging themselves a deepeer hole from which it is impossible to get out of And also from spreading loadsa dangerous rubbish Try this link it tells you everything about batteries and their care Even I learned something from it after working with batteries and elecrical systems for over 40 years www.uuhome.de/williams.dauden
Link to comment
Share on other sites

Glad you found the deliberate mistake - put in to see if you could use the grey matter Like Clive I have over 40 years in the business Well actually if we are counting 50 years And certificates in electrical and electronics - including some from the military qualifying me to work on aircraft electrical systems - including batteries and chargers Just blow up the electronics in your own MH if you wish but dont expect ME to take your advice
Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...