Dual battery setup for 2.8 1GD

[KentyScotchy]

Thanks mate that does sound exactly in line with my needs. Budgets no issue as I'm happy to pay for what's necessary to get a quality setup. That being said I don't like to throw away money on things I don't need.

I only do the rough driving with the boys (wife tends to panic) but I have had a few tales of misadventure getting lost in some pretty ordinary mountain ranges (could be reason why the wife panics) so I'll go for the aftermarket mount as a better to be safe than sorry option. I'd be interested to see photos of your install, especially where you mounted the sockets for the kids if you have any to share?

Also does anyone have a cheat sheet re lifting sills, running cables Etc to make my life a little easier?

I'll put a list of items up in line with this install and seek some feedback on quality/reliability. I've used no name eBay isolator a in the past without incident, but looking at something like the redarc sbi12 this time. I have t started looking at an mppt yet as I may source a panel with one attached. Happy to hear the opinions of others...thick skin, looking to learn from others experiences. I have no locked in preconceived preferences. Thanks again
Kenty

[InnerCityBoy]

Hi KentyScotchy

Your budget, style of camping and amount of off-road may be different to mine but I have similar needs, I went for a deep cycle battery under the bonnet connected to the alternator via a RedArc isolator. This runs to a cig lighter in the back to power my 35l fridge, USB sockets in the rear seats for the kids and it also runs through to an Anderson plug on the rear to send charge through to my camper (which has an onboard battery that is charged through a DC charger).

The second battery under the bonnet easily runs the fridge for a couple of days, I could charge it with my solar panels but have never needed to as I rarely wouldnt drive the car at least a short distance every couple of days when camping and this seems to keep it topped up enough.

In your shoes I would get an under-bonnet battery which would be hassle free for your weekly use. Don’t bother with an after-market mount unless you do a lot of rough driving. Be careful to get a battery that is warranted for under-bonnet use, as some AGM batteries aren’t (mine is an SSB 130Ah AGM which has a 3 yr warranty which covers under-bonnet use). I would not get a DC charger for an under-bonnet second battery, but think they’re a must for remote batteries (such as a battery in a camper trailer) due to the voltage drop over the distance from the alternator. Don’t get a cigarette socket installed for the fridge (as I did), the lead constantly falls out on the road; get a Merit or Anderson plug instead.

Hope this helps ... good luck!

[KentyScotchy]

I've spent many hours over the past couple of weeks reviewing dual battery options. I'm no closer to knowing the best way to go as I have half a dozen variable components that do or don't go well together in different situations. So perhaps out of frustration/confusion/laziness I'm going to ask directly:

What should I get?

Car: 2017 Prado GXL (2.8 Diesel)
Usage:
monthly short overnight trips (no power)
Quarterly long trips 1 - 2wks (predominantly no power)

Accessories: Waeco CFX65 (permanently mounted and gets used weekly)
Led lighting
Other occasional plug and play 12v accessories

Presently, I run from a removable battery box in the boot which I charge via ctek when home or solar when away.

I want to mount in the bonnet, run cable to rear for fridge (dedicated connection), a couple of extra accessory plugs and an anderson plug to tow bar. Considering an Anderson plug somewhere for a solar panel too (will buy a new panel as I'm giving my old one to my son).

So if anyone would be kind enough to dictate terms to me; I'd appreciate it! Don't worry about options, just tell me in your experience what you feel is the best set up. From battery mount, dcdc etc or anything else I need. Brands models...ill take your advice!

I've wired a dual battery before in the past which worked fine, but I care a lot more about the Prado than I did the old car so I want to get as close to best as possible. Thanks in advance!

[dBC]

Half your luck... I'd say I'm down a good 0.2V on yours, and in much cooler conditions.

[120D4D]

For those playing at home, the dash display says its currently 40c here in Adelaide and Weatherzone says 37.7c - after around an hour behind the wheel in city traffic I curiously checked the alternator output at the main battery terminals.

13.62v (fluctuated from 13.60 to 13.65 with a/c cycling).

Potentially, it may be able to drop to 13.5v but I'm still seeing 13.65 - 13.95 in all but the extreme weather days.


Starting to wonder if the 5A / 15A output referred to in the manual may be related to the sensitivity to temperature compensation...

[LeighW]

The 12V would have been an issue, my Lithiums are around 12.9V with 20% SOC.

The other issue is Lithiums don't like being float charged once they are fully charged, float charging them will shorten their life.

The advantage of chargers like the Enerdrive DC2DC units are you can set the charge rate, the maxium charge voltage and the charging current to switch off at. Once the terminal voltage reaches the target voltage and the current drops to the target value the charging stops and it goes into power supply mode. You can set the voltage output in power supply mode between 13.0V-13.8 (0.1V Step) ie you can set it to a voltage slightly below the terminal voltage of your fully charged Lithium battery so that it supplies any accessory loads but doesn't charge the battery. When the battery terminal voltage drops to 13.2V or the charger is turned off and on again it will resume charging.

[LeadWings]

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.

Leighw, out of interest do you know why they didn't recommend them for lithiums?

I'm currently running a Projecta IDC 25 in my camper to my 100 AHr lithium and works fine - It has a simple 3 stage charging algorithm (CC, CV and float) I used the Gel 14.1V setting, and so far has worked a treat.

[drivesafe]

Hi Piggy and sorry mate, I was unaware of any advertising?

[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.

<advertising removed>

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.

[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.

[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]

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?

[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.

[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]

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.