Rear Dual battery

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Tinus lotz
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Re: Rear Dual battery

Post by Tinus lotz » 19 Jun 2017 19:56

The idea is to connect only critical things to the second battery like fresh meat and cold beer :rolling:

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Re: Rear Dual battery

Post by NoPressure » 07 May 2019 10:13

David M wrote:
19 Feb 2017 17:52
The idea behind the box is that I can leave it in the vehicle or remove and leave at a campsite with the fridge etc.....

If remaining in the vehicle I have a solar input plug and 12V input or output in the back bumper which can plug into the box inside.

Power Station top.jpg

Inside is fairly basic with battery cable input from C Tek and decent wiring to the outputs as well as the C Tek's temperature sensor.

Power station input.jpg

The red is for solar in to the C Tek and the large grey is from the cranking battery with battery cabling.

Power station C Tek.jpg

The C Tek has a marine switch as a bypass for if I want power to the front battery for winching or starting if cranking battery packs up.

Power Station output.jpg

There are 2 grey inputs/outputs, a blue input/output for higher amperages (eg. inverter), double 2.1A USB, Hella and cigarette connections. As mentioned earlier one of the grey connectors connects to the back bumper if required so I can leave the car locked while for example charging the battery from 220V. Each of the inputs/outputs is separately fused and if a fuse blows a LED lights showing which one.
Good day David

Camping with friends this weekend, and they suddenly had their vehicle pouring smoke out as we were relaxing under the shade. It made me re-assess how my 12v setup is fused. (I had done it many years ago - which might be a problem as I know very little about the finer points of 12v systems).

My question is as follows- how do I go about calculating the right amp fuse to use?

If I recall correctly you want the normal constant draw to be ~80% of the fuse rating, but this should obviously be less than the amp rating of the electrical wire?
I see you have a 30 and 16amp blade fuse - for what are those respectively?
What about the trickle charger - it fluctuates in voltage delivery - or do you just use the wattage indicator on the unit to determine what amps would be max?

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Re: Rear Dual battery

Post by Tunja » 07 May 2019 10:53

Tinus lotz wrote:
19 Jun 2017 19:56
The idea is to connect only critical things to the second battery like fresh meat and cold beer :rolling:
:rolling: :rolling: :rolling: :rolling: :rolling: :rolling: :rolling: :rolling: :rolling: :rolling: :rolling:

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I have 2 x loose boxes with on off switched and brad harris connectors, will take and post some pix later.
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Re: Rear Dual battery

Post by Tinus lotz » 07 May 2019 16:54

Jip man why connect things that needs a alternator to run to second battery ? Only critical things must connect to it

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Re: Rear Dual battery

Post by David M » 30 May 2019 17:44

NoPressure wrote:
07 May 2019 10:13
David M wrote:
19 Feb 2017 17:52
The idea behind the box is that I can leave it in the vehicle or remove and leave at a campsite with the fridge etc.....

If remaining in the vehicle I have a solar input plug and 12V input or output in the back bumper which can plug into the box inside.

Power Station top.jpg

Inside is fairly basic with battery cable input from C Tek and decent wiring to the outputs as well as the C Tek's temperature sensor.

Power station input.jpg

The red is for solar in to the C Tek and the large grey is from the cranking battery with battery cabling.

Power station C Tek.jpg

The C Tek has a marine switch as a bypass for if I want power to the front battery for winching or starting if cranking battery packs up.

Power Station output.jpg

There are 2 grey inputs/outputs, a blue input/output for higher amperages (eg. inverter), double 2.1A USB, Hella and cigarette connections. As mentioned earlier one of the grey connectors connects to the back bumper if required so I can leave the car locked while for example charging the battery from 220V. Each of the inputs/outputs is separately fused and if a fuse blows a LED lights showing which one.
Good day David

Camping with friends this weekend, and they suddenly had their vehicle pouring smoke out as we were relaxing under the shade. It made me re-assess how my 12v setup is fused. (I had done it many years ago - which might be a problem as I know very little about the finer points of 12v systems).

My question is as follows- how do I go about calculating the right amp fuse to use?

If I recall correctly you want the normal constant draw to be ~80% of the fuse rating, but this should obviously be less than the amp rating of the electrical wire?
I see you have a 30 and 16amp blade fuse - for what are those respectively?
What about the trickle charger - it fluctuates in voltage delivery - or do you just use the wattage indicator on the unit to determine what amps would be max?
Ruan - I would determine the fuse sizes by "phoning a friend" - ie. Jacques from Bushpower.
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Re: Rear Dual battery

Post by TijmenvdS » 31 May 2019 06:27

Essentially I first check the power draw of what is connected, if it is a fridge: Snomaster 66L is rated at 5 amps so I would put in a fuse of Minimum 7.5A and maybe 10A. Or if you don't know what you are going to connect, put in a fuse rated lower than the wire thickness, you want the fuse to pop before your wires ignite. That can be calculated with https://www.solar-wind.co.uk/info/dc-cable-sizing-tool and adjusting "acceptable losses" between 3-5% But phoning a friend is the best and safest just to check if he concurs.
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Re: Rear Dual battery

Post by biggles » 06 Oct 2019 22:37

biggles wrote:
08 Mar 2017 15:07
biggles wrote:My box from bushpower is clicking away for 30 seconds rapidly. And that happens regularly... almost as though the solenoid doesn't know if it shjould be on or not. Is that normal?

I have also contacted Jaques.
Apparently it is normal :rolleyes:
So I found out 2 years later what that clicking was... I ended up replacing the whole bushpower unit with a ctek... and it never quite worked at expectation. Long trip the battery would not charge and I would have warm beer. I was beginning to get very disillusioned over the whole dual battery story. Then the ctek stopped charging and had all lights flashing... that particular combination was not in the manual, but it clearly indicated something was not quite correct.

I hauled the battery box out and put it on an ac- dc charger. First direct to the battery in recon mode, thinking the battery was faulty. Then after it was charged I connected the ctek dc-dc charger in 12v supply mode and it worked perfectly. So the charger was not the problem. I traced the Wi-Fi g to the main battery and opened the fuse holder.

Somebody had not pinched the But holding the 50A fuse in and it had worked loose. Having done the whole thing myself there was not many people to blame. But the fuse nut had held for about 6 months before coming loose. Vibrating it was always kicking solenoid in and out hence the clicking on the bushpower unit. And it got worse with time and the ctek obviously just got confused and shut down.

Since tightening the fuse I always have a fully charged battery.

The fuse holder was melted on the inside. Obviously the loose connection was arcing the whole time.
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Re: Rear Dual battery

Post by Pieter B » 10 Oct 2019 17:13

Krisis.......6 maande se warm bier :lol:

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