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Solar vs Split Charge

Andy Walker

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I have a 1995 landcruiser 80 ., it is fitted with 2 Numax cxv30hmf 113Ah 1000mca batteries.
I want to ensure that when I park up overnight camping and using lighting and fridge that there will be enough battery power left to start the engine the following morning.
Assuming the batteries start with a full charge and the alternator is working correctly, then using a 45l Engel fridge and low wattage lighting(not sure exactly how much) then should the above batteries be enough.?
If not - am I better trying to fit a 3rd battery somewhere in the rear of the vehicle as there doesn't seem to be spare space under the bonnet and a split charge.?
Or a solar panel to the existing batteries ?
Or a solar panel to a 3rd battery ?
How big a solar panel would I need ?

Or is there another better option ????

I don't think I want a 3rd battery fitted permanently in the rear, but if a 3rd battery was put in a plastic box, could I wire a split charge via an anderson connector ?????
 

Crispin

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A solar panel would not run the fridge overnight :)lol:) and depending on the fridge requirements, would not solely run it either.
A 50W panel, measuring about 800x500mm, has a maximum output of around 2.7A. Your fridge, when running would be a lot more than this.
The above is only true in full sunlight, when you have full sunlight you can assume your fridge has the most work to do.

A 3rd battery with a proper split system (even a simple relay) would be best. That way, when the fridge does run the battery down, all you have is some warm beer. Your engine will still crank.
The solar panel will only slow the discharge down as it will substitute some of the power requirements as well as recharge the battery when the fridge is not running. A worthy item if you can have one.

If you don't want the 3rd battery in all the time, get some quick connect clips for it, a nice battery box and only use as you need. (a good trickle charger when in the garage won't hurt)
There's no reason you could not use the Anderson connector - just never accidentally plug anything else into the charger side of it.
 

Crispin

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just had a look at the specs for the 40L Engel fridge. It's current draw @12V is 2.5A so a 50W panel would work to run the fridge by day. It would leave no room though to recharge anything. At full tilt, 200ma residual is little and that is in direct sunlight.

Split charge me thinks would offer more peace of mind...
 

pugwash

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dual 90ah batteries in my truck- have had the truck off for well over 48 hours with the fridge on and its never had any problems starting. you'll be fine for at least 24.
 

tonytone

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We solo travel a lot and in our vehicle we have a split charge going to aux battery located at the rear of the truck in one of the side compartments of the drawer system. Lighting , fridge cb and inverter run from this battery.

However during one of my more paranoid times I was still of the opinion that if the main batteries failed ..that would be it , we'd be stuck . So we nor have a 35l realyusefulbox that contains a honda ex350 generator (9kg 350watts) a 20 amp battery charger and 3 litres of pre mixed 2 stroke petrol. So flat battery, failed alternator , we will be good to go and at least reach a repair point if I don't have the spares to fix in situ.

It will run for over 2 hrs on 1L of fuel.

Tony
 

Gary Stockton

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See this topic for a split charge system to a 3rd battery that has an Anderson Connector going to the alternator:

viewtopic.php?f=19&t=35

Works well for me!

Cheers
 
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Paul_Humphreys

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A numax CXV 27 wil run my Minus40 Fridge/frezzer for about 60 hours without starting the car. I do mean to fit a CVX30 on it aswell (on the list of things to do). But you can fit 3 battires under the bonnet. I also have a small solar panel that keeps the 3rd battery topped up when the LC is parked up and not used.

Paul
 

Chas

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Paul,
Can the solar panel be left connected while the engine is running and the alternator charging?
Chas
 

Paul_Humphreys

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Yes, as there is a oneway resistor/switch/controller/what ever it is :)
 

Andy Walker

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Paul_Humphreys said:
A numax CXV 27 wil run my Minus40 Fridge/frezzer for about 60 hours without starting the car. I do mean to fit a CVX30 on it aswell (on the list of things to do). But you can fit 3 battires under the bonnet. I also have a small solar panel that keeps the 3rd battery topped up when the LC is parked up and not used.

Paul

Can you post a photo of where a 3rd battery of this size will fit under the bonnet.. Or is it a custom made battery tray I would need??
 

Paul_Humphreys

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I think Julian makes a try to fit them I just "made" mine fit. I don't have a picture, but could take a picture tomorrow.

Paul
 

Chas

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Julian V fitted one in my 80, it's a squeeze but possible.
Chas
I'd put a picture on but I've still got to figure out how to do that :(
 

Rob

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I asked Julian about his battery tray and he said that it will only be able to fit optima sized batteries on it. The tray is on one side and accommodates the extra stater battery and the leisure battery but you should change all 3 as using different batteries for your main car batteries shortens their lives quite a bit apparently.

Has anyone managed to fit 3 full size batteries under the bonnet?
 

Paul_Humphreys

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Rob, I have a standard battery on the drivers side. A newmax 27 and Lucaus 655cca on the other side. I will have to take pictures for you.

Paul
 

keith richardson

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The question is:- Solar vs Split charge
Answer is :- use BOTH

In my 105 LC I run the following - controlled by a split charger and a solar regulator
1 x AC Delco 75AH cranking battery
2 x AC Delco 105AH deep cycle batteries (connected in parallel)
1 x Sharp 80W solar panel (regulated at 14.5V, capable of 5.0AH during sunlight)
2 x National Luna 40 ltr freezers (one runs as a freezer the other runs as a fridge)

When installing a split charger, fridge/freezer and or solar panel - to limit the volt drop always use a minimum cable size of 16sq mm (25sq mm preferred) for everything.
Ensure that all connections use properly sized and crimped connectors or are soldered.
Use anything smaller than 16sq mm and you will be p1$$1ng into the wind.

For a deep cycle battery to achieve more than 80-85% SOC (state of charge) it requires 14.5V
If your alternator is only putting out 13.7-13.9V (Land Cruiser standard) the chances of you ever getting maximum efficiency out of your deep cycle batteries is zero.
By using the solar panel and alternator to charge the batteries, when driving I normally achieve an average charge voltage of 14.2-14.3V. However when I park I get 14.5V, depending on sunlight and panel position efficiency.

In our neck of the woods it is very likely that during the day you will get a minimum of 11 hours of sunlight.
I have been able to park off at a camp site for a full 3 nights (4 days), with both fridges running at Max, and never running the engine, using only the solar panel to recharge the batteries, and according to the solar regulator the deep cycle batteries were still at 65% SOC (state of charge)

IMO for travelling in Africa or the desert, the solar panel was by far my best investment and one of the best accessories I ever bought.
 

Rob

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Paul_Humphreys said:
Rob, I have a standard battery on the drivers side. A newmax 27 and Lucaus 655cca on the other side. I will have to take pictures for you.

Paul
Did you get a chance to take some photos yet Paul?
 
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