Dual battery setup for 2.8 1GD

[LeadWings Member Find all posts View Profile Close LeadWings]

Hey dbc,

No solar panels yet but I did wire up the Anderson plug to the solar input so it's ready to go. my dad is going to give me a good quality solar panel that's surplus to his need but it is an inbuilt regulator. Does this mean it can't be used with the bcdc1225d?

Just put a set of Andersons (or the same connector that you have for the leads to the battery) between the panel and the inbuilt regulator - then you can use it normally (ie to charge other batteries) but when you want to use it on the Redarc bypass the inbuilt regulator and connect the lead to the Redarc straight from the panel outputs.

[rpn Junior Member Find all posts View Profile Close rpn]

Last night I installed a Projecta IDC25 DC-DC charger in our 2.8 GXL. It's quite straightforward to install, although a little fiddly routing the heavy cables around the engine bay. I haven't connected the IGN sense wire as yet, it seems to work without it. Certainly better charge volts on the Aux battery compared with main battery.

Happy with the pricing, the IDC25 kit with 50A fuses for each battery was about $300 delivered, plus a few $$ for cables and terminals. I used a Century deep cycle battery that I had from a previous vehicle and sat it in a modified Piranha tray and used the standard Toyota clamp mounts.

[LeadWings Member Find all posts View Profile Close LeadWings]

Last night I installed a Projecta IDC25 DC-DC charger in our 2.8 GXL. It's quite straightforward to install, although a little fiddly routing the heavy cables around the engine bay. I haven't connected the IGN sense wire as yet, it seems to work without it. Certainly better charge volts on the Aux battery compared with main battery.

I used one of these in our camper trailer, very happy with it. I found even with 6 B&S/AWG cable (about 10m worth from battery to camper battery) I needed the IGN sense wire connected as the voltage in goes down to around 11 V at times.

[120D4D Avid PP Poster! Find all posts View Profile Close 120D4D]

That's a huge voltage drop LeadWings and suggest your alternator is putting out around 12.5v on idle?

[rpn Junior Member Find all posts View Profile Close rpn]

I used one of these in our camper trailer, very happy with it. I found even with 6 B&S/AWG cable (about 10m worth from battery to camper battery) I needed the IGN sense wire connected as the voltage in goes down to around 11 V at times.

I originally allowed for the IGN sense but after measuring main battery volts when the engine is running decided it wasn't needed.

Maybe try measuring the voltage drop across connectors (Anderson etc) and terminals in the cable run, both pos and neg. May have dirty or loose connections.

[drivesafe Senior Member Find all posts View Profile Close drivesafe]

Hi LeadWings, as Michael posted, that is a huge voltage drop.

If your alternator was operating at 13.6v, with a 40 amp current draw over 10m of 6B&S twin ( 2 x 6B&S ) you should still be getting 12.48v at the input of your DC/DC device, so something is seriously wrong with your setup.

Even with an alternator voltage of 13.2v, you should be getting at least 12.1v at the input of the DC/DC device.

[LeadWings Member Find all posts View Profile Close LeadWings]

The issue I had was when I first started the car in the morning at idle, when the DC-DC kicked in and sucked the 30A it needs to make 25A to the battery the voltage would sag till the alternator/engine responded the higher load and pulled the volts back up again, but the voltage sag caused the Dc-Dc to trip. When diagnosing the issue I had my volt meter on the DC-DC in, which is where I saw the voltage drop (briefly) to around the 11V I mentioned.

If I put the idle up button in or held the revs up, this would not happen - ie the voltage would not sag as low.

If it did not drop when the DC-DC first kicked in, then it would be all good from then on and with an alternator output of 13.4V I see around 12.2V at the Dc-DC - so Drivesafe this agrees with the numbers you noted.

So really the issue was a cold engine just idling and the low voltage the system runs at, and the time it takes to respond to the fairly sudden demand of an additional 30A. For other loads (eg turning spotties on) this would not be an issue, but for the DC-Dc that has a low voltage cut-out it can be an issue.

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

The Enerdrive DC2DC units might be more suitable in this situation, they monitor the input voltage and when they see the alternator has started charging they turn on, they continue to monitor the input voltage and if it drops the charging stops and it monitors the input voltage to see if it recvovers if it does it assumes the voltage drop is caused by the wiring and starts charging again. It continues to monitor the input voltage at regular intervals. If the input voltage drops to much and the unit determines the alternator is still charging it reduces its output current to protect the undersize input wiring.

Disadvantages of these units are they are quite big and not waterproof as they have a cooling fan, advantages apart from above are they a fully user programmable have a display to show you what's going on and appear to be very robust.

[Usernamewill Junior Member Find all posts View Profile Close Usernamewill]

What are people's thoughts (and knowledge) on this setup?

https://www.jtsonline.com.au/the-ult...ttery-kit.html

The try looks the part, but without knowing much about the battery it's hard to tell whether it's a good deal or not.

I'd like to have my dual battery done for summer but battery choice is where I'm stuck at!

Will.

[LeadWings Member Find all posts View Profile Close LeadWings]

The Enerdrive DC2DC units might be more suitable in this situation, they monitor the input voltage and when they see the alternator has started charging they turn on, they continue to monitor the input voltage and if it drops the charging stops and it monitors the input voltage to see if it recvovers if it does it assumes the voltage drop is caused by the wiring and starts charging again. It continues to monitor the input voltage at regular intervals. If the input voltage drops to much and the unit determines the alternator is still charging it reduces its output current to protect the undersize input wiring.

Disadvantages of these units are they are quite big and not waterproof as they have a cooling fan, advantages apart from above are they a fully user programmable have a display to show you what's going on and appear to be very robust.

We have just bought a new camper trailer, which means the fridge is moving from the camper into the back of the car so I am looking into how I will do the electrics. I was poking around and was surprised at the products that have recently hit the market - for example the Intervolt one below looks pretty slick also and is IP67. Remote panel is pretty neat and a good idea also.

http://www.intervolt.com/product/in-...ttery-charger/

Anyone any experience with these?

[Usernamewill Junior Member Find all posts View Profile Close Usernamewill]

I asked about the intervolt a few pages ago and didn't get much. Popular with the navara users from what I can tell. Not sure how their alternator output on the np300 compares to the 2.8 prado.
Looks like a solid product that can do it all.

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

Couple of points for the intervolt:

It derates its output if the environment exceeds 50C so might not be the best choice for under bonnet.

From the owners manual:

"Boost: The boost stage, also known as bulk charge (and other pseudonyms) is the stage when the Charging Device is producing the heavy current required in order to re-charge a depleted battery as quickly as possible. The boost voltage is determined by the battery type selected in the initial set-up phase. The boost stage is controlled by an algorithm of time vs voltage vs temperature to ensure that the battery is charged optimally under the given conditions. In boost stage the charger is operating in constant current (CC) mode and will produce up to 25 Amps (maximum) subject to the aforementioned conditions. When the Charging Device is powered up and the auxiliary battery measures 12.0V or below the boost stage is then initialised. At this point the ‘soft start’ function is also enabled (see page 7 for detailed information) and current flows. The boost stage is completed or terminated under the following conditions:"


The "When the Charging Device is powered up and the auxiliary battery measures 12.0V or below the boost stage is then initialized" is interesting, what exactly does that mean, if the battery is above 12V what rate does it charge at? If a reduced rate then might not be for those that want to recharge their batteries quickly when they are above 12V?

[LeadWings Member Find all posts View Profile Close LeadWings]

The "When the Charging Device is powered up and the auxiliary battery measures 12.0V or below the boost stage is then initialized" is interesting, what exactly does that mean, if the battery is above 12V what rate does it charge at? If a reduced rate then might not be for those that want to recharge their batteries quickly when they are above 12V?

Yeah it is unclear what trickery is in the control software - so how it will perform in the real world. This is especially interesting to me as I use lithium batteries - so really I want a simple algorithm of constant current till the set point voltage then constant voltage from then on, and a voltage set point that will suit my batteries.

I like the fact it has a shunt and displays the current on the remote display. It would awesome if they went one step better and had a shunt to the battery, and used it to measure/integrate current (AH) to and from battery so it gives a state of charge of the battery.

[LeighW Avid PP Poster! Find all posts View Profile Close LeighW]

I had discussions with them a few months back, they didn't recommend the charger for use with Lithiums, I went for the Enerdrive for that reason.

[drivesafe Senior Member Find all posts View Profile Close drivesafe]

Dual battery setup for 2.8 1GD

Hi Leigh and if you are charging a single small to mid size lithium battery then any of the above is fine.

But if you are needing to charge a large lithium battery or a number of lithium batteries, then there is a much better setup, but this is more for someone starting from scratch.

You get a Sterling 1,000w inverter with RVD-EI protection, and a Sterling PCU1260, a 60 amp battery charger.

You power the inverter from an ignition controlled power supply running from your cranking battery, to the inverter in a caravan.

The inverter powers the 60 amp battery charger, which is set to one of the 2 Lithium charging algorithms pre-set in these chargers and and you can’t do much better.

When you are on a powered site, just plug the battery charger into mains AC and when you are camping off the grid, the 1,000w inverter can supply you with AC power.

A good feature of these chargers is that they has 3 outputs, so you can run all 3 to the battery bank, or you can run two outputs to the battery bank and the third output can be used to power a 3 way fridge, independently of the batteries.

This setup gets around having to bring two separate power supplies into the caravan. One for the batteries and a separate one for a 3 way fridge. Just run a one twin 25mm2 power supply.

And the above setup works with any lead acid or lead crystal battery banks.

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NOTE to make the inverter safe to operate while on the road, it must be protected by an RVD-EI.

Another really useful feature of the new Sterling battery chargers is that they are UL 1236 SB listed, the highest build standard. California Energy Commission CEC Rated. I&rsquo;ll not go into details here, but this is a big energy saver when you use these battery chargers to maintain house batteries between trips.