Ford Transit Forum

by **garycooper** » Thu Feb 18, 2010 11:00 am

Hi guys

Just got my 2000 v reg transit for Karting

What i like to do is connect another battery this will charge from original altanater

but be only used for powering an inverter in the rear of the van for laptops and other small devices for the day

and when i come to start the van at the days end it will still start from the original battery(no more flat battery)

anyone help or now of a guide to do this

thanks

Gary

http://www.GazTecKarting.co.uk

by **KH_Towbars** » Thu Feb 18, 2010 12:08 pm

Hi, you need one of thesehttp://cgi.ebay.co.uk/Smart-12s-Switchi ... 35a5cd3feb
it only charges the aux battery when engine is running.
can help you if required

by **GBBiker** » Thu Feb 18, 2010 2:28 pm

Won't need the relay if the second battery is running independantly.

All he needs to do is connect the earth to the block and the + to the alternator (the same terminal the main battery is connected to). This will charge the second battery and it will be independant of the vehicles main circuits (ie; starter and ancilliaries). It will be charged while the engine is running and will not affect the other battery.

by **bazw** » Thu Feb 18, 2010 2:58 pm

GBBiker wrote:Won't need the relay if the second battery is running independantly.

All he needs to do is connect the earth to the block and the + to the alternator (the same terminal the main battery is connected to). This will charge the second battery and it will be independant of the vehicles main circuits (ie; starter and ancilliaries). It will be charged while the engine is running and will not affect the other battery.

this is how i did mine , works a treat

by **AlanN** » Thu Feb 18, 2010 3:17 pm

GBBiker wrote:Won't need the relay if the second battery is running independantly.
All he needs to do is connect the earth to the block and the + to the alternator (the same terminal the main battery is connected to). This will charge the second battery and it will be independant of the vehicles main circuits (ie; starter and ancilliaries). It will be charged while the engine is running and will not affect the other battery.

Yes both batteries will charge, but what stops power-flow back to the other battery then, if both are earthed and both have the same source, they are connected!!! What disconnects the battery from the alternator then? One of the common faults with alternators is that they drain the battery when the diode pack fails. It would also mean the battery would be assisting in cranking the starter motor :shock:

by **KH_Towbars** » Thu Feb 18, 2010 4:47 pm

GBBiker wrote:Won't need the relay if the second battery is running independantly.

All he needs to do is connect the earth to the block and the + to the alternator (the same terminal the main battery is connected to). This will charge the second battery and it will be independant of the vehicles main circuits (ie; starter and ancilliaries). It will be charged while the engine is running and will not affect the other battery.

yes can be done that way but would make it easier if the aux battery is in the rear of the van to use the relay and just pick a constant live up from fuse box but like alan says wouldn't it still be connected to the other battery if you wired to alternator?

by **AlanN** » Thu Feb 18, 2010 5:20 pm

I wouldn't normally recommend halfrauds, but they do a nice quality charging kit, with all the heavy cable, fuses etc. to do the job in the caravan/camping section. I fitted one to Nada's van recently, much better quality than mine, but if I remember rightly, it cost about £14 - 16. Has the auxcillery output too.
But you being a towbar fitter would have in the back anyway :lol: