Talbot charging question

[Guest M.C]

Hello, doe`s the leisure battery which is housed under the bonnet of my Talbot autosleeper get charged from the alternator when the engine is running? M.C

[Guest Clive]

Connect a digital voltmeter across the leisure battery when the engine is running. The voltage should be above 12.6 volts and aiming towards 14 volts if its been working OK. If the voltage remains near 12 with the engine running or not then the answer is NO.

[Guest Derek Uzzell]

Not sure if a 2nd opinion is really needed after Clive's reply, however here goes... It would be odd for a leisure-battery to be fitted to a motorhome (particularly an Auto-Sleepers motorhome) without an on-board means of charging it, and the simplest way to do this is via the vehicle's alternator. Normal UK practice is to use a split-charge relay that, when the vehicle's engine is running, splits the alternator's output between vehicle-battery and leisure-battery. It should be relatively easy for you to spot such a relay by following the wiring leading from the batteries. Before checking your leisure-battery's basic state of charge, make sure that at least an hour has passed since the vehicle's engine has last been running - otherwise (if the charging system is working properly) you are likely to get a confusingly high reading. Connect a voltmeter across the leisure-battery's terminals (as Clive describes) and expect a voltage reading of around 12.7V (if the battery is in good condition and 100% charged) or below (12.0V or less indicates fully discharged). Then start the engine and you should see a significant rise in voltage towards 14V or above. If this doesn't happen then there is most probably a fault in your 'van's electrical system. I'm a mite uncertain whether you are just asking a technical question or whether you've got a problem with your leisure-battery's state of charge. It's fair to assume your 'van's alternator is charging OK (else you'd soon have a discharged vehicle-battery and the engine would fail to start) and there could be several reasons for a leisure-battery failing to hold charge or not being charged. If you want an easy-to-read overview of motorhome electrical systems (and all the other bits and bobs) I recommend John Wickersham's recently-revised "The Motorcaravan Manual" (Haynes Publishing).