Second battery.

[[email protected] Junior Member Find all posts View Profile Close [email protected]]

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.

I really don't think where it is made will affect the quality of a product.

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

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.

My mistake on that one, it is a temperature sensing one. However though in the Prings at the moment it is getting 20 during the day and 2-3 overnight, which is faily typical for most of Australia's climate. The alternator (which has a voltage booster) is putting out 14.4-14.5 above idle and 14.2 at idle on cold nights which then drops to 13.9-14.0 after 20 minutes or so. One would argue though that with the minimum 0.3 volt gain that the diode gets that the cold voltages are 14.1-14.2 (or possibly less if I am getting the full 0.5 volt increase that the diode claims to be able to do) and 13.6-13.7 after 20 minutes.
As drivesafe stated successive 20 minute drives will eventually charge the battery much like using a cup to fill a bath will eventually fill it, however the storage of AGM batteries at lower than 100% charge damages them. Further to, after consultation with Optima directly the charging of their Bluetop batteries at a charging voltage of less than 13.85 volts WILL damage them over time. So drivesafe is correct, however it will damage the battery by A: keeping it for long periods at less than full charge, and B: using a charging voltage less than 13.85 volts.
I learned this all the $380 broken battery hard way...

[GEEEXL Member Find all posts View Profile Close GEEEXL]

My mistake on that one, it is a temperature sensing one. However though in the Prings at the moment it is getting 20 during the day and 2-3 overnight, which is faily typical for most of Australia's climate. The alternator (which has a voltage booster) is putting out 14.4-14.5 above idle and 14.2 at idle on cold nights which then drops to 13.9-14.0 after 20 minutes or so. One would argue though that with the minimum 0.3 volt gain that the diode gets that the cold voltages are 14.1-14.2 (or possibly less if I am getting the full 0.5 volt increase that the diode claims to be able to do) and 13.6-13.7 after 20 minutes.
As drivesafe stated successive 20 minute drives will eventually charge the battery much like using a cup to fill a bath will eventually fill it, however the storage of AGM batteries at lower than 100% charge damages them. Further to, after consultation with Optima directly the charging of their Bluetop batteries at a charging voltage of less than 13.85 volts WILL damage them over time. So drivesafe is correct, however it will damage the battery by A: keeping it for long periods at less than full charge, and B: using a charging voltage less than 13.85 volts.
I learned this all the $380 broken battery hard way...

Sounds like the optimas are better off on a DCDC

G

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

Hi Jimmy and based on the operating info you have posted up, your Optima should have been fully charged and the alternator is not the potential cause of your battery’s early demise.

Even though your alternator dropped back to lower voltages, the fact that it was operating at high enough voltages for short periods means your battery should have been fully charged after a few drives.

All lead acid batteries control their own final stage of a charge cycle.

This is usually from around when the battery gets to about 80% State of Charge ( SoC ) and from that point on, regardless of what type of charging device is being used, the battery itself controls the amount of current it will now absorb.

In this final stage of the charge, the higher the applied voltage, the faster the battery will reach a fully charged state.

Now this may sound like a DC/DC device, with it’s higher FINAL STAGE voltage, is the answer, but this is not the case.

With a DC/DC device, you first have to get the battery up to around 80% before the charge current starts to taper off and the DC/DC device’s higher voltage could be an advantage.

Whereas with an alternator, the charge current actually begins to taper off right from the start of the charge cycle.

The difference, particularly with an Optima Battery in a low charged state, is that the starting current can easily be 60+ amps and this type of current is likely even when the alternator’s operating voltage has dropped.

I have read where someone had flattened their Optima Yellowtop over a weekend camp and the starting current when they began their trip home, was 97 amps.

Now while, as posted above, most batteries control the final stage of the charge from around 80% SoC, but Optima state that their batteries can be rapid charged to 90% and so, when using an alternator as the charge device, an Optima is going to reach the Absorption stager sooner than is capable with a DC/DC device.

Even with short drives, because the Optima is brought up to 90% SoC mach sooner, each time you start a drive, the higher initial alternator voltage will eventually get the Optima to a fully charged state.

Once the battery is in a fully charged state, it will not discharge just because the alternator voltage drops back.

For any battery to start discharging while you are driving, your alternator voltage has to drop below 12.7v.

So Jimmy, everything you have posted would indicate your short battery life was caused by something other than short drives and your alternator’s operating voltages.

[dBC Member Find all posts View Profile Close dBC]

after consultation with Optima directly the charging of their Bluetop batteries at a charging voltage of less than 13.85 volts WILL damage them over time.

Interesting datapoint there, and not one that they reveal in their datasheet as far as I can tell, so thanks for sharing. That doesn't bode well for folks with the 2.8L engine where this is no diode solution. If I'm really lucky, mine starts at 13.8V (even on a cold winter's morning) and almost immediately drops down to ~13.6V. On long hot drives I see it get as low as 13.4V. All those measurements are taken from a dedicated feed straight off the cranking battery posts.

That's two manufacturers now (Odyssey and Optima) who have stated that low charging voltages greatly reduce the battery life in deep cycle applications, even if those low voltages are capable of getting it fully charged.

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

Hi dBC and you are reading things the way you think they are, not what is required.

The inference is that if the charge voltage NEVER gets above 13.85v, then over a period of time, the battery may be damaged.

This does not mean the voltage has to be above 13.85v at ALL TIMES.

So once again, with the voltage starting out at a higher level, then you should have no problems getting Optimas to a fully charged state, but with short drive conditions, it will only happen after possibly quite a few drives, but it will still be able to be fully charged.

[GEEEXL Member Find all posts View Profile Close GEEEXL]

Go Mr Alternator Go

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

dBC - do you have a VX/Kakadu with DRL's or just the 'lights always on' of the GX/GXL?

If you have a GX/GXL, do you drive with the light switch OFF or do you like some, drive with the Parkers on? - I'm wondering if the voltages you're seeing are from Lights ON or OFF?

[dBC Member Find all posts View Profile Close dBC]

Mine is a Kakadu with a row of DRL LEDs. It doesn't feel like it's a voltage sag situation... it seems to maintain whatever voltage it's set its mind to, regardless of what loads I throw at it.

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

Hi Jimmy and based on the operating info you have posted up, your Optima should have been fully charged and the alternator is not the potential cause of your battery’s early demise.

I disagree, see my comment about from Optima about how charging below 13.85 volts WILL damage the battery. Voltages between 13.2 and 13.8 are only recommended by Optima for float charging. The recommended charging voltage for the d34M is between 13.85 and 15.0 volts with a recharge time of 35 mins @100A, 75 mins @50A and 140mins @25A. - Source Optima battery Website and Aussiebatteries website

Even though your alternator dropped back to lower voltages, the fact that it was operating at high enough voltages for short periods means your battery should have been fully charged after a few drives.

Yes, just like filling up a bathtub with a cup will eventually fill it. However it is a known fact that storing a battery at a lower state of charge will reduce its lifespan. So the time periods between the short drives where the battery is essentially 'in storage' at less than full charge will damage it. So if I go camping overnight and I discharge it to 50% SOC which is 12.05 volts and then drive home 10 minutes the battery may only reach 12.3 volts (arbitrary figure). Allowing an AGM battery to be 'stored' below 12.4 volts will damage it over time. This damage is caused by sulfation and reduces the capacity. Much in the same thought that 1 cigarette won't shorten your life noticeably, but repeated cigarettes will. Source- Optima website, Aussie batteries.

All lead acid batteries control their own final stage of a charge cycle.

The bluetop is an AGM battery.

In this final stage of the charge, the higher the applied voltage, the faster the battery will reach a fully charged state.

Only to a maximum of 15 volts

The difference, particularly with an Optima Battery in a low charged state, is that the starting current can easily be 60+ amps and this type of current is likely even when the alternator’s operating voltage has dropped.
I have read where someone had flattened their Optima Yellowtop over a weekend camp and the starting current when they began their trip home, was 97 amps.

Still is a 35 minute (minimum) drive to charge it back up.

So Jimmy, everything you have posted would indicate your short battery life was caused by something other than short drives and your alternator’s operating voltages.

I disagree, the battery may also have had some faults, however I feel all the evidence I have provided suggests that the charging system played a major part. There was a mention about how I live in a warmer part of aus, this may play a part, but after 5 minutes the internal temperature of the alternator will be the same regardless as the engine warms up to a higher temperature than ambient so the ambient temp is null. And as I have stated it is currently mid 20's in Alice during the day and I am still getting low voltages (adjusted for the AOC I installed recently) so the temperature sensing can't have a huge amount to do with it.

[dBC Member Find all posts View Profile Close dBC]

(adjusted for the AOC I installed recently)

Jimmy, did your Optima failure pre-date the installation of the AOC?

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

I disagree, see my comment about from Optima about how charging below 13.85 volts WILL damage the battery. Voltages between 13.2 and 13.8 are only recommended by Optima for float charging. The recommended charging voltage for the d34M is between 13.85 and 15.0 volts with a recharge time of 35 mins @100A, 75 mins @50A and 140mins @25A

Hi Jimmy and you can disagree as much as you like but it does not alter the fact that you do not understand even the most fundament requirements for charging and maintaining lead acid batteries.

For a starter, you only need 13.85v for the final stage of the charge, not for the entire charge cycle.

Next if you had read all the info on the Optima site, you would know that those times relate to charging their batteries from 0% SoC to 90% Soc, not 100%, and furthermore, it does not have to be a single drive of 75 minutes while charging at 50 Amps. It could 3 x 25 minute drives while charging at 50 Amps, or 5 x 15 minute drives while charging at 50 Amps.

All the above drive times will give you a total of 75 minutes and in each case, the battery will be at 90% SoC.

Yes, just like filling up a bathtub with a cup will eventually fill it. However it is a known fact that storing a battery at a lower state of charge will reduce its lifespan. So the time periods between the short drives where the battery is essentially 'in storage' at less than full charge will damage it. So if I go camping overnight and I discharge it to 50% SOC which is 12.05 volts and then drive home 10 minutes the battery may only reach 12.3 volts (arbitrary figure). Allowing an AGM battery to be 'stored' below 12.4 volts will damage it over time. This damage is caused by sulfation and reduces the capacity. Much in the same thought that 1 cigarette won't shorten your life noticeably, but repeated cigarettes will.

I have already answer half of this above, but what do you mean by STORED?

If you mean the battery is to be removed when you get home and stored away for a long period, then the responsibility is yours to make sure the battery is fully charged by an alternate charge source BEFORE you store the battery.

If the battery is staying in your vehicle and you mean that the battery is not going to be charging till you next drive your vehicle. Well sulfration requires two factor to be present. As sulfration does not occur in batteries that have an SoC of 75% or higher, and if the battery's SoC is lower than 75%, then the battery must sit in a No-Charge/No-Load state for at lest 24 hours before any sulfration begins. So if you know your vehicle is not going to be used for a while, and you already know that the Optima is in a low state of charge ( SoC ) then again, it would be negligent of you if you did not apply alternate charge source, and this has absolutely to do with whether an alternator can properly charge a battery, it is your driving habits that are causing the potential problems for the battery.

The bluetop is an AGM battery.

Again, this statement demonstrates your lack of knowledge of this field. An AGM is a lead acid battery, a wet cell or flooded battery is a lead acid battery, a Gel cell is a lead acid battery.

Only to a maximum of 15 volts

I have no idea what you are trying to imply here.

Still is a 35 minute (minimum) drive to charge it back up.

SEE ABOVE

I disagree, the battery may also have had some faults, however I feel all the evidence I have provided suggests that the charging system played a major part. There was a mention about how I live in a warmer part of aus, this may play a part, but after 5 minutes the internal temperature of the alternator will be the same regardless as the engine warms up to a higher temperature than ambient so the ambient temp is null. And as I have stated it is currently mid 20's in Alice during the day and I am still getting low voltages (adjusted for the AOC I installed recently) so the temperature sensing can't have a huge amount to do with it.

Once again, this comes back to your own personal driving habits and not some mythical failure on behalf of an alternator to be able to charge a battery.

With all your accusations above, of how you reckon an alternator was your problem, then please suggest how you think you could resolve the problem?

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

Jimmy, did your Optima failure pre-date the installation of the AOC?

Hi, yes it failed prior to AOC installation. Cheers.

Drivesafe; I believe the issue is the low charging voltage of the 150 series Prado. The solution is either to boost the charging voltage by either installing an AOC or DC/DC charger.
Couple of clarifications regarding my post. By storage I mean sitting in the car with no load/no input. ie. sitting overnight. When my VSC is disconnected there is 0 load on the aux battery, essentially it is in the car 'in storage'.

How do you respond to the email directly from optima themselves that charging a bluetop at any less than 13.85 volts will damage it? Yes if the battery is already at 90% SOC or so then the 20 mins of >13.85 volts will be fine before the alternator voltage declines, but if you go camping and run the battery down to 40 or 50% SOC then 20 minutes of above 13.85 will not charge it, then the rest of the drive home with less than 13.85, as you and I agree, will eventually charge it, but WILL damage the battery.
All you have to do is google the issues associated with variable output alternators and dual batteries

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

Hi Jimmy and sorry mate, you are misinterpreting what you are reading.

The people at Optima are trying to tell you your problem is not whether the voltage goes over 13.85v, but the fact that you are not driving long enough to recharge the battery even if the voltage is above 13.85v.

As I have already posted, and Optima’s E-mail confirms what I have been trying to tell you, your issue is not caused by the battery or your alternator, it is solely caused by your driving habits.

Now to your supposed solutions, of which, neither will resolve your issue.

Even if you raised the voltage to 14.7v, because of YOUR SHORT DRIVE TIMES, you are still going to have an undercharged battery at the end of your drive.

As for adding a DC/DC device. As DC/DC devices charge low batteries at a MUCH lower voltage than your alternator does, then your issue will be made even worse if you fit a DC/DC device and still do short trips.

If this is your everyday drive vehicle, then as your battery is not sitting for more than 24 hours in a No-Charge/No-Load state, there is no chance of any sulfration even starting to occur.

The chemical reaction in all lead acid batteries require at least 24 hours in a No-Charge/No-Load state before the chemical reaction ceases.

Until the chemical reaction ceases, sulfration does not occur.

You do not drive long enough so you need to finish the charging of your battery by other means, when you at at home.

[Guest Close Guest]

As for adding a DC/DC device. As DC/DC devices charge low batteries at a MUCH lower voltage than your alternator does, then your issue will be made even worse if you fit a DC/DC device and still do short trips.

I think you mean current.