D4 2nd battery charging

Hi GD-4, first cab off the rank. Can you post up your driving habits. Like how often do you drive and when you drive, what is the rough average time for each drive.

As far as the Optima goes, try putting a small load on it, like a compressor fridge and see how long the fridge runs before the voltage gets down around 12.0v.

The cranking battery voltages will depend on your drive times, so I'll wait for you reply.

GD 4,

I have same vehicle as yours,same dual battery system,although my vehicle is MY 12.
My vehicle also often does short trips or only gets used for a few days a week.Main battery was replaced about a year ago under warranty,optima is around 3 yrs old.

I charge mine regularly,with the same Ctek charger as you use.Often every weekend or every second weekend.I try and leave it on for at least 36 hours.

I have checked the battery voltage every now and then,and similar to you seems to sit around 12.8V.Both batteries will always read the same voltage until the Sc80 isolates the batteries which is at 12.0 V,main battery voltage.

I remember the Sc80 would flash its green LED after two days of the vehicle sitting idle after giving the batteries a good charge,when the main battery was on its way out.

Now i never see the green LED flashing.

There may not be anything wrong with your batteries,or if there is mine has the same issue.
I charge both batteries together,and use the AGM auto setting on the charger.

Hi Tim

I drive it for 1 week (6 days - daily return trip of 40 minutes each way, 80 mins altogether. This is in city traffic) and the car sits in the car porch for 1 to 2 weeks and then I'll drive it for another week and the same cycle repeats itself. So the car gets driven every 1 in 2 to 3 weeks. Unless I am going outback or on a trip. Have not done a long trip since a 2 week Vic high country trip in March this year.

I know that is bad for the battery!

However, I charge it for at least one day every weekend for 10 -12 hours at a stretch. Sometimes both days of the weekend. The Ctek always go to the float mode when I disconnect. I do not charge overnight.

AS for connecting the Fridge to the aux battery, I will need to find a weekend that I am home all weekend.

Thanks

GD -4

Hi GD-4, and unfortunately, you are your own worst enemy.

The daily 40 minute drives are more than ideal ( when done in regular continuos use ) and the traffic situation is not a problem because of the huge alternator capacity in these vehicle.

BUT!!!

Your charging routine is next to useless because it is not the CHARGE cycle that will benefit your batteries, it is the FLOAT cycle that is needed to condition the batteries after they have been sitting unused for so long.

To get the best benefit from any charging of batteries, you need to leave the batteries on a FLOAT cycle for 8 to 10 hours.

The first part of the charging cycle, the BULK charge, will do just that, it will charge the batteries, but it is only charging the battery capacity that can still be charged.

This chargeable capacity diminishes the longer you leave batteries in an unused state, and your 40 minute drives are doing the same thing, you are only recharging the usable capacity.

By leaving the batteries in FLOAT mode for 8 to 10 hours, you will very slowly recondition the batteries and will most likely recover lost battery capacity.

This is a long process but it will be worth the effort as it will help to extend the operating life span of your batteries.

Best procedure, if you can do it, is to put the charger on the batteries and leave the charger on, in float mode for 8 to 10 hour. Leaving them on in float mode for more than 10 hours offers not additional gain.

Then turn the charge off for at least 10 to 12 hours and repeat.

By turning the charger off for 10+ hours, you let the battery's electrolyte settle.

Then when you turn the charger on again, even when the batteries are fully charged, all battery chargers will start in the BULK charge cycle, even for a short time.

The initial BULK charge cycle will stir up the electrolyte, then the float mode will have fairly evenly mixed electrolyte and this helps to recondition the battery.

Thanks Tim. This is exactly what we have found recently with the battery in the young bloke's RX7 which doesn't get driven very often these days.

He came home from work recently to find the battery virtually dead in it. After an initial bulk charge to allow him to start and drive the car, he used his CTek charger as you have described above over a period of three or four days, leaving it on "float" charge overnight for three nights I think, and the battery now seems to be as good as new.

The mechanic who services SWMBO's Camry told her last week when it was serviced that she needs to take it on a long drive to Coolgardie or similar to bring the battery charge back to where it should be. I charged it with my CTek, and then left on "float" cycle overnight for a couple of nights (with her using the car during the day) - and this also seems to have done the trick. Battery is now showing a higher charge in the mornings than it was before it went in for service.

I plug the CTek into the Anderson plug from your kit on the back of my Disco overnight about once every couple of months or so - it keeps all three batteries in the vehicle in a pretty healthy condition.

Thanks Tim,
I will do that and report back

GD-4

Tim for the sake of the cause and because I am interested in your views I just checked ours, MY15 TDV6 with 19,000 km just rolled over in 10 months. The vehicle usage may be different from average in that the car does a lot of country travel and subsequently long distances at cruising speed as well as towing our Ultimate camper if we are either 4wd training and/or running a tagalong. For example our recent five day testing session in the North Flinders ranges meant >6 hours engine on from Adelaide to Blinman and towing and on one track >4 hours in low range. This is just to give you an idea of our duty cycle

We had a 160 system with the Orbital fitted in January. That battery just read 12.38V and the cranking battery read 12.32V. Engine has been off since around 1500 yesterday

Regards

Rob

Hi Rob, are you at home now and if so, how much driving have you done in the last week

If you are still out travelling, do you have a fridge running?

The voltages indicate your batteries are around the 75% SoC mark.

While not any problem, but this is a little bit lower than I would expect to see, if you are driving your D4 regularly.

Tim we got back from a week in the Flinders on Tuesday so the car has had plenty of work over that period. They are conditioned every couple of months using a RedArc Smart Charger as the D4 is the touring car so when back in town it doesn't get a lot of use so I just put the charger on and leave it. I tend to condition the Orbital and then the starting battery.

There is no current draw once back in town but we have a 50l Waeco in the back when touring

I have been watching my SOC with interest since the start of ownership and the only time I see 100% is immediately post charging. From there they drop to 12.70-12.5 quickly

Rob

Rob, something is not quite right with your system as those measurement are actually closer to 70% SoC.

You have lost about 40+ Ampere Hours of battery capacity in a very short time.

How much driving have you done since you got back and how long was your last drive before you took the latest measurements?

Also see if you can take a measurement with the motor running.

If you have not had this low voltage before, it may be because the BMS is carrying out a battery condition test and if this is so, don't be to surprised if you get down to 12.2v with the motor running.