Second battery.

[Sketchy Pete Lurker Find all posts View Profile Close Sketchy Pete]

So what is the general consensus for the second battery what is everyone using please. I'm going to be running a fridge and some LED lights. Looking for options without all the bs from someone trying to make a quid out of me. Thanks in advance...

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

Go for an Allrounder http://www.supercharge.com.au/allrounder.html

Stay away from Optima

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

Go for an Allrounder http://www.supercharge.com.au/allrounder.html

Stay away from Optima

Why's that?

[Piratepete Member Find all posts View Profile Close Piratepete]

Based on all the recommendations in PP, I went with the Optima D34. At least 2 years now. Important reason in 2012 Prado was room against the AC pipe. Have had no problems whatsoever. Ok, it's not the biggest Ah but has had no problems running an ARB 60 litre fridge overnight, uhf connected to it. Seems like whenever volts go down after long use it's back up to charge in no time after a short drive. Fits great in ARB battery tray. Good agm battery but Yep it's pricey, think I paid $320. Btw, original cranking battery still in place after 5 years and 3 months and Toyota said still looking good at last service. Wish I could find more batteries that last that long.

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

Why's that?

I had an Optima in my prado 120, lasted about 18 months. started leaking and would struggle to run the fridge for longer than 1 day. I have read others who have had similar problems since optima started getting the batteries made in mexico. Apparently they used to be great batteries until this happened.

I have had the Allrounder in my Prado 150 and have not had an issue with it.

do a google search for optima batteries now made in mexico and have a read and see what you think.

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

Just replaced a 4 y.o. D34 optima with another one (blue one this time). I know 4 years is not a long life, but went with another due to the small size, relatively light weight and very quick charge. Time will tell
Cheers

[JimmyC Advanced Member Find all posts View Profile Close JimmyC]

I just replaced a optima after less than 2 years. I have a VSR in place and it turns out that's what kills them

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

What do you mean JimmyC?

How does a VSR kill an Optima?

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

Hi Jimmy and I too would like to know how a VSR type isolator kills Optima batteries.

My last Optima D34 was used as a cranking battery in my wife’s Toyota Seca, when her cranking battery died.

The Optima lasted two and a half years, but it had been used in a dual battery system for six year and then sat around the workshop for nearly 18 months, before being used as the cranking battery.

So 10 years out of an Optima and 6 of those were in a VSR type dual battery setup.

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

I don't have a VSR

[JimmyC Advanced Member Find all posts View Profile Close JimmyC]

So the VSR is not the direct killer of the battery, but it's use rather than a smart charger.
The Prado (150 series, not sure about the 90 or 120's) uses a smart alternator which reduces the output of the alternator after approx 20 minutes of driving to the 13.3 to 13.5 volt range. If you have 1 lead acid battery as your starter then this is fine as it will be fully charged and on a float when the alternator reduces its output. If you have a dual battery then if you use some of its capacity then it requires recharging and 20 minutes at 14 volts is not enough.
If you have 1 lead acid as your starter and 1 AGM as your dual (as I did) then the output from the alternator is not enough.
This is directly from the Optima website:
BLUETOP Type: D34M / D31M/ D27M
These batteries are dual-purpose. They are designed for engine starting and deep cycling applications, as well as for use in boats with large accessory loads.
Recommended charging information:
Alternator:
13.65 to 15.0 volts, no amperage limit.
Battery Charger:
13.8 to 15.0 volts, 10 amps maximum, approximately for six to twelve hours.
Cyclic Applications:
14.7 volts, no current limit as long as battery temperature remains below 125°F (51.7°C). When current falls below one amp, finish with two-amp constant current for one hour for D34M and three-amp constant current for one hour for D27M and D31M.
Rapid Recharge:
Maximum voltage 15.6 volts (regulated), no current limit as long as battery temperature remains below 125°F (51.7°C). Charge until current drops below one amp.
Float Charge:
13.2 to 13.8 volts, one amp maximum current, time indefinite (at lower voltage).
Strictly adhere to all limits.

The Prado smart alternator just cannot achieve that. So the use of the VSR that just allows the alternator voltage through rather than a smart charger (or an alternator output compensator) will not allow the battery to properly charge.

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

Hi again Jimmy and sorry mate and while a single 20 minute drive will not fully charge an Optima from a low state to a fully charged state ( anything 95% or higher ) but a number of 20 minute drives will fully charge an Optima.

So if you are only doing a single 20 minute drive and then using your Optima between this drive and the next,yes, your Optima will not be able to be fully charged.

This type of situation would have nothing to do with an alternator’s ability to recharge the Optima, it is the limited drive time that is the problem and that is a user caused problem.

If on the other hand, you did a number of short drive of say just 15 minute each, then these short drives would most certainly allow the alternator to bring the Optima up to a fully charged ( 95+% ) state.

So because Optimas are rapid charge batteries, your ordinary garden variety VSR will have no problem fully charging an Optima, depending on your own driving habits.

[dBC Member Find all posts View Profile Close dBC]

The Prado (150 series, not sure about the 90 or 120's) uses a smart alternator which reduces the output of the alternator after approx 20 minutes of driving to the 13.3 to 13.5 volt range.

At least you get 20 minutes. The alternator voltage output on my 2.8L starts low and stays low. Without occasional external assistance from an AC charger, even my cranking battery ends up resting at 12.2V after typical city driving runs for a few weeks. I think the new alternator is "smart" in the sense that it's controlled by the ECU, but as far as I can tell the algorithm is simply start low and stay low. My camping battery (only ever charged by a 25A DC/DC charger) always rests at 12.6/12.7.

There's a good graph on p14 of this datasheet: http://www.odysseybattery.com/docume...M-002_1214.pdf that shows what low charging voltages can do to the life of that particular make of battery while undergoing deep cycles. I don't know whether Optima have similar data for their batteries, but I think your basic reasoning is sound Jimmy. There's more to this than just how quickly you can recharge a deeply discharged deep cycle battery..... battery longevity matters for most of us too.

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

Hi dBC, you can not use the specs from one type/brand of battery to indicate that this is how another battery will function and your post is a perfect example of what happens when you misunderstand the differences between battery types.

Odessay Batteries require a totally different charging algorithm to an Optima, and if you have a look at the Optima web site you will see they specifically state that their batteries can be fully charged with alternator voltages from 13.65v to 15.0v. And this info has already been posted up by JimmyC

So if JimmyC Optima is very low, and he only partially charges his battery during the first 20 minute drive, successive 20 minute drives will have no problem bringing his battery up to fully charged state.

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

JimmyC, the Prado 150 (1KD and 1GD) alternator is not a 'smart alternator' like you see in other vehicles it is 'temperature compensating' and I note you and dBC are both located in the warmer parts of our great land.

I'm seeing much higher warm voltages that you two and put that down to ambient temps, notwithstanding that even in a hot SA summer I still dont see voltages as low as you.

Not much assistance I know - just an observation.