21 replies to this topic

[Mark@IR]

ive got a 90amphour battery and a 50amp battery and a 70amp alternater, is there a way of having both charging at the same time as with it being a show car i cant afford to not have enough power for the amps but then like you say i need to be able to start it!

Firstly, starting issue.. This is why i suggest 2 volt metres. If your main 'starting' battery seems a bit low, before you turn your engine off, turn your sterio off and let her charge up a bit. Secondly, your audio is sucking up loads of juice, so the volt metre on the 'audio' battery will let you know if your eating through the full battery.

As it stands now, you watch the power cap figures, whats it start at when audio isn't on, then what figure does it drop to under full crank?

As for your betteries, Defo need bigger and deep cycle. The battery i mentioned before is Yellow top battery, click me

If your wanting more from your system, don't skimp on the important bits.

[insamoufonyx]

ok cheers for all the input, currently considering just making the battery box bigger and putting a heffer of a battery in it, alot less hassel it seams, and i dont have to try and shide a second battery then.

but on the split harge front, if i was to turn of the things drawing from the "lesure battery" would the no draw make the relay charge the other battery yes?

and what sort of voltage should my batterys be sitting at?

cheer

[Bungle]

the biggest draw on your starting battery is the starter motor

so you start your mini the engine starts and the alternator charges up the starting battery

after a minute or 2 thats charged and the leisure battery gets the spare juice

can't really see its a problem unless the show you are driving to is less than a minute away

you can always charge up your leisure battery before you go to a show so that you know its 100%

[Bungle]

here [/url]

only problem with this way is you run your leisure battery low at a show

you then turn the key for the journey home motor spins the charge light go off and relay kicks in

both battery's are now connected together

but the engine isn't started yet and the leisure battery wants power (might only be for a few seconds) you end up blowing the 30 amp fuse

at least thats what happened to me and many other camper van owners and why we use voltage sensing relays

[Guess-Works.com]

I seem to remeber that may off road (4x4) drivers run a split charge system, and there's probably kits out there to do the whole lot for you in one box.

[Mark@IR]

I seem to remeber that may off road (4x4) drivers run a split charge system, and there's probably kits out there to do the whole lot for you in one box.

There is indeed kits, this ones a cheapy..

Click Me

Gives you a better idea of whats involved then.

[SpaceframeGT]

We use this vsr a lot on split charge systems see link http://www.power-sto...i...amp;id=197 the other alternative for charge rates below 35A is a blocking diode system . I like the VSR method because its simple to connect .
To control alternator output there are also special voltage regulators and battery management systems available see http://www.adverc.co.uk/
and if you need battery cable and connectors try http://www.autoelect...t/products.html
Hope this helps.