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If you want to use your Bongo as a camper van then it's a good idea to fit a second battery to run your interior lights, radio and camping junk from. Using a simple split charging system you can insure that you don't run you main starter battery down whilst being able to charge your leisure battery whilst on the go.
If you're fairly competent then the the job should take about 2 hours to complete.
If you're interested in Mazda Bongos check out the U.K. owners club here Bongo Fury
If you're fairly competent then the the job should take about 2 hours to complete.
If you're interested in Mazda Bongos check out the U.K. owners club here Bongo Fury
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Signing UpStep 1What exactly are we doing here
First things first. We need to clarify exactly what we are trying to achieve.
I am not going to describe how to wire up your goodies or how to rewire the internal lights etc to run from the leisure battery (that's another howto). I am going to explain how to wire up a split charging circuit so that your leisure battery gets charged up as you drive along.
Your starter battery is connected to the alternator of the van so when you drive along it gets charged. If we connect our leisure battery in parallel to the starter battery it will also get charged as we drive along.
Unfortunately it's not quite that simple. There are a couple instances when we don't want the two batteries connected.
1) Since the starter battery is the most important battery we need to insure that it gets fully charged before we even think about charging the leisure battery.
2) If we are stationary and using the onboard electrics we don't want to risk a flat starter battery so we must ensure it's disconnected from the leisure battery.
To do this we use a special relay that connects / disconnects the two batteries according to the above criteria.
The special relay is a variously called a voltage sensing relay (VSR), smart relay, battery isolator and several other names I can't remember.
It works by only making its switched connection when the input volatge reaches a preset level and unmaking its switched connection below that preset level.
To make sure we only charge the leisure battery when the engine is running and the starter battery is fully charged we need the VSR to make at about 14 volts. When the engine is not running or the starter battery is not fully charged the VSR will see less than 14v and so won't make. This matches the criteria set out earlier.
So our simple parallel circuit now has a smart switch added.
I am not going to describe how to wire up your goodies or how to rewire the internal lights etc to run from the leisure battery (that's another howto). I am going to explain how to wire up a split charging circuit so that your leisure battery gets charged up as you drive along.
Your starter battery is connected to the alternator of the van so when you drive along it gets charged. If we connect our leisure battery in parallel to the starter battery it will also get charged as we drive along.
Unfortunately it's not quite that simple. There are a couple instances when we don't want the two batteries connected.
1) Since the starter battery is the most important battery we need to insure that it gets fully charged before we even think about charging the leisure battery.
2) If we are stationary and using the onboard electrics we don't want to risk a flat starter battery so we must ensure it's disconnected from the leisure battery.
To do this we use a special relay that connects / disconnects the two batteries according to the above criteria.
The special relay is a variously called a voltage sensing relay (VSR), smart relay, battery isolator and several other names I can't remember.
It works by only making its switched connection when the input volatge reaches a preset level and unmaking its switched connection below that preset level.
To make sure we only charge the leisure battery when the engine is running and the starter battery is fully charged we need the VSR to make at about 14 volts. When the engine is not running or the starter battery is not fully charged the VSR will see less than 14v and so won't make. This matches the criteria set out earlier.
So our simple parallel circuit now has a smart switch added.
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That's a very condensed way of putting it but, in essence, to answer your question, yes, a true deep cycle battery is best but a leisure battery is fine and a fair bit cheaper.
If you are interested the difference is in the way the battery is made. Deep cycle batteries have much more heavy duty plates and some are chemically different (as well as there being specialist gel batteries).
Well done.
Take care.
Kevan
the isolator is $20 USD on ebay and the distribution block is around $7 - $20 USD (anything over $20 USD is over priced!) on ebay.