Dual battery setup for 2.8 1GD

[404pug Avid PP Poster! Find all posts View Profile Close 404pug]

oops. Yes 13.5-13.6v charging. By the way I am using a "Kickass"" VSR

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

Thanks guys i'll look into the Traxide. Is the factory battery a throw away item?

Not at all - in fact you may find the factory battery last a good 5 years plus (if looked after and not cycled too much).

[robby4675 Lurker Find all posts View Profile Close robby4675]

Thanks guys, really appreciate the wealth of knowledge on this thread, after reading the whole thing I'm looking at the SC80 VSR. Just need to work out which 2nd battery i'm gonna go. Any recommendations? Checked out the Optimas on the weekend whilst at Autobarn picking up a pioneer platform. The optimas look the biz but low amp hours?? Maybe a marine pro?

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

For those looking at putting in a dual battery system, I was just discussing a problem with someone, he has had a dual battery system installed in his car, the installer fitted an SSB 100Ah battery, and he fitted a booster diode. He found down the track that the SSB capacity was dropping and on examination the battery had swollen.

I looked up the battery and it said heavy duty suitable for starting application etc, when I looked at the specs I was very surprised to see the max charge rate specified as 12.5A and regular charge rate 5A. This battery may be rated for starting purposes etc but I certainly would not be connecting it directly to an alternator as the recharge current of the battery when it is low is most likely going to be well in excess of 12.5 amps. I had a quick look at a couple of other of their AGM batteries and they had similar specs.

I would be only using these batteries with chargers that can limit the current to below the 12.5 amps, preferably 5A max.

Cheers
Leigh

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

As I posted earlier I have been seeing from 12.25 – 12.40v at the cranking battery of a morning. I’ve been testing the Traxide SC80 isolator for a couple weeks now and see 12.50 – 12.60v with the SC80 using it’s ‘shared mode’. Up until now I have been using a Redarc BCDC1220 exclusively.

The alternator on my 1GD seems to put out around 13.80v on average. On a cold morning I saw 14.0v (only tiwce) and a hot morning as low as 13.65v. The state of charge of the batteries seems to have little effect and it’s mainly the ambient temps that effect the output.

If I switch the SC80 over to ‘storage mode’ it isolates like a traditional VSR and will get my Optima up to 12.75 – 12.80v easily enough.

After talking to Drivesafe I did expect the cranking battery resting voltage to come up using the SC80 but was genuinely surprised at how quick I managed to recharge the Optima AUX with the SC80.

One test I (accidentally) started with just under 11 volts in the Optima, I went for 2 x 10 mins runs and left the car off (and fridge on) for 30 mins then read 12.47v at the AUX. It ran down again to 12.28 over a couple of hours and after 1 x 20 min drive it was back up to 12.55v. Not a very precise test I know, but using the BCDC and assuming max 20A output the whole time, I couldn’t have put back in more than approx 15AH.

For those that stop and camp or are heavy power users I would say consider the Traxide dual purpose isolator on their Prado. I’m only a light user and find it works well, the SC80 is pretty handy in being able to switch modes and I don’t know why Drivesafe doesn’t push his product more!

[404pug Avid PP Poster! Find all posts View Profile Close 404pug]

Something to watch. After a recent trip I noticed that the 2nd battery tray in my 2.8 had been in gentle contact with the hose to the intercooler as shown by a slight mark in the dust. It happens as the motor moves slightly on its mounts. The tray is a Supercheap one and obviously is a fraction too long so it will be replaced ASAP!

[GEEEXL Member Find all posts View Profile Close GEEEXL]

For those looking at putting in a dual battery system, I was just discussing a problem with someone, he has had a dual battery system installed in his car, the installer fitted an SSB 100Ah battery, and he fitted a booster diode. He found down the track that the SSB capacity was dropping and on examination the battery had swollen.

I looked up the battery and it said heavy duty suitable for starting application etc, when I looked at the specs I was very surprised to see the max charge rate specified as 12.5A and regular charge rate 5A. This battery may be rated for starting purposes etc but I certainly would not be connecting it directly to an alternator as the recharge current of the battery when it is low is most likely going to be well in excess of 12.5 amps. I had a quick look at a couple of other of their AGM batteries and they had similar specs.

I would be only using these batteries with chargers that can limit the current to below the 12.5 amps, preferably 5A max.

Cheers
Leigh

Leigh W

Leigh

just wondering where you found the specs on that SSB battery???

I have the below battery from what I can find the specs are far different from your numbers?? & cant really understand how a 12v battery would get charged to 100% and only 12.5v???

Part Number HVT-70ZZD
BATTERY TYPE AGM VRLA - Cyclic Use
REGULAR CHARGE 10.0 Amps
MAX CHARGE 29.4 Amps
Maximum recharging voltage is 14.6 Volts.

http://www.superstart.com.au/Product...19/Default.asp

G

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

Their Website.

The specs will vary from battery to battery, even with the specs you have quoted, if the battery is regularly discharged to 50% SOC how are you going to limit the charge current to 10A or even 29.4 amps when charged directly off an alternator?

Even if you could limit it to 10A why would you want a battery that is going to take 7+ hours to charge from 50% SOC, not much use in a touring situation where you may be depending on recharging the battery in a typical days drive?

Cheers

[GEEEXL Member Find all posts View Profile Close GEEEXL]

Their Website.

The specs will vary from battery to battery, even with the specs you have quoted, if the battery is regularly discharged to 50% SOC how are you going to limit the charge current to 10A or even 29.4 amps when charged directly off an alternator?

Even if you could limit it to 10A why would you want a battery that is going to take 7+ hours to charge from 50% SOC, not much use in a touring situation where you may be depending on recharging the battery in a typical days drive?

Cheers

I have had 4 vehicles over my time with duel batteries running standard lead acid deep cycle batteries, some quite large, and in one ute we had 3 across the front of the ute body as a bank. 3 of these cars i have run off VSR's and although i was happy with their performance the battery i quoted above running off a BCDC has outperformed the other installations quite convincingly pound for pound, granted the VSR setups were not aided with solar like the current BCDC unit

I have no agenda to push regarding VSR, diodes or BCDC. I'm not in the industry and cant give a rats about all the hoo harr as long as the beer is cold, but i am very very impressed with the SSB battery I have been running. With a 1 hour return commute my 40l fridge is self sufficient in the car and no issue over the weekend even if that car is not used with no solar asistance.

Do you have the model number of the battery that experienced the swelling and overcharging?

im also wondering how the F you would get a 12v battery charged with a max charge rate of 12.5v?? - i almost thought you made a typo and meant 13.5v

G

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

im also wondering how the F you would get a 12v battery charged with a max charge rate of 12.5v?? - i almost thought you made a typo and meant 13.5v

G

Well in his post it actually says 12.5A as in amps

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

Firstly my point was to alert those installing a dual battery system that some batteries may not be suitable for direct charging off an alternator, or high output DCDC chargers for that matter ie check the suitability of the battery for the intended use.

Secondly where did I write "max charge rate of 12.5v"

Thirdly I'm not pushing anything as you put it as I have already made it quite clear boosters are not an option for the 2.8.

[GEEEXL Member Find all posts View Profile Close GEEEXL]

Firstly my point was to alert those installing a dual battery system that some batteries may not be suitable for direct charging off an alternator, or high output DCDC chargers for that matter ie check the suitability of the battery for the intended use.

Secondly where did I write "max charge rate of 12.5v"

Thirdly I'm not pushing anything as you put it as I have already made it quite clear boosters are not an option for the 2.8.

Sorry Leigh I didn't read the 12.5 A part correctly and hence why i was scratching my head, I appreciate your contribution to the site and was just barking up the wrong tree

must be a Friday

beer o clok me thinks

always fixes the muddled head from a long working week

[GEEEXL Member Find all posts View Profile Close GEEEXL]

still interested in a response to

"Do you have the model number of the battery that experienced the swelling and overcharging?"

G

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

Sorry I can't recall, the guy told me the number over the phone but I didn't wright it down,
he'd changed it for a Century deep cycle battery and had had any issues with that to date.

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

As I posted earlier I have been seeing from 12.25 – 12.40v at the cranking battery of a morning. I’ve been testing the Traxide SC80 isolator for a couple weeks now and see 12.50 – 12.60v with the SC80 using it’s ‘shared mode’. Up until now I have been using a Redarc BCDC1220 exclusively.

The alternator on my 1GD seems to put out around 13.80v on average. On a cold morning I saw 14.0v (only tiwce) and a hot morning as low as 13.65v. The state of charge of the batteries seems to have little effect and it’s mainly the ambient temps that effect the output.

If I switch the SC80 over to ‘storage mode’ it isolates like a traditional VSR and will get my Optima up to 12.75 – 12.80v easily enough.

After talking to Drivesafe I did expect the cranking battery resting voltage to come up using the SC80 but was genuinely surprised at how quick I managed to recharge the Optima AUX with the SC80.

One test I (accidentally) started with just under 11 volts in the Optima, I went for 2 x 10 mins runs and left the car off (and fridge on) for 30 mins then read 12.47v at the AUX. It ran down again to 12.28 over a couple of hours and after 1 x 20 min drive it was back up to 12.55v. Not a very precise test I know, but using the BCDC and assuming max 20A output the whole time, I couldn’t have put back in more than approx 15AH.

For those that stop and camp or are heavy power users I would say consider the Traxide dual purpose isolator on their Prado. I’m only a light user and find it works well, the SC80 is pretty handy in being able to switch modes and I don’t know why Drivesafe doesn’t push his product more!

Hi Michael, thank you for carrying out the testing for me, and you are quite welcome to keep the unit and post up what you find.

While I already have a number of new Prados fitted out with my isolators, and the isolators are doing there job, your feedback is the best info so far, because you have had the experience of already having a DC/DC setup in your new Prado and being able to compare the two types of charging systems.

The real test will come when you do that longer trip you are planning.

Even though you are doing lots of short trips, the SC80 is still charging and more importantly, conditioning your cranking battery.

By the time you go on that trip, because your cranking battery is not only kept in a higher state of charge, because the way the SC80 allows the auxiliary battery to continually condition the cranking battery. Over a period of time, this continual conditioning of the cranking battery increases the cranking battery’s capacity and in most case, increases it back up to the battery’s original capacity when new.

So when you go on that trip, you will now have around twice the usable capacity you had with your DC/DC setup.

Even if you still only use the same amount of battery capacity you use to use with your DC/DC setup, when you go for a drive, you will, as you have areal mentioned, replace used battery capacity much, MUCH faster then any DC/DC setup can do.

As for promoting my gear, most of my work comes from word of mouth referrals, and feedback like yours, and this keeps me flat out.

Again, thank you Michael for the excellent feedback.