View Full Version : Charging flat battery
corbijn
24th January 2018, 11:17 AM
Hi All, twice over the last. fortnight we have now had a flat battery whilst camping in our 2008 D3. My guess is opening and closing doors too much! 
Either way I understand that I should properly charge the battery. I have a Project IC1500 for my Camper trailer and it looks like it would do the job.
https://www.projecta.com.au/battery-charger-products/12v-automatic-15a-7-stage-battery-charger (http://archive.boston.com/yourtown/malden/articles/2011/11/20/take_care_when_jump_starting_battery_or_risk_fryin g_cars_computers/)
I am concerned though about frying electrics. There is so much talk out on the internet.
My understanding is - pick the right battery type, connect the cables in the correct order then turn the charger on.
I am also not sure which charge rate I should use, the table on page 10 refers to AH, I assume that would be Amp Hours?
Is that right.
Am I missing something significant?
Uberdisco
24th January 2018, 11:28 AM
Your battery shouldnt being going goat from opening and closing doors at camp. Especially if you adjust internal lights not to turn on. I have had my radio blaring for 3 hrs(aux socket relay jumped) and still not get a flat battery. It might be a old battery? Or a drain somewhere else?
06 Disco 3
corbijn
24th January 2018, 11:47 AM
Thanks UberDisco, The battery is 2.5 years old, and we hadn't set the lights not to turn on. I really should have thought of that! But yes, I do need to investigate the cause. 
I will take the car to a battery shop to get them to check the battery this afternoon. Assuming it still has good I plan to connect it to the charger later tonight. Just want to make sure I follow the steps correctly.
101RRS
24th January 2018, 11:53 AM
There is nothing special about charging a battery in a D3/D4 except where the -ive charging goes - on the body earth post rather than the -ive side of the battery.  Just take the same precautions as charging any car.
When my old battery was dying I had to charge it a few times using my old supercrap smart charger - positive clip to the +lead on the battery and the negative clip to the earth post on the body just in front of the battery - and just left it until the charger said charged - no issues.
Garry
corbijn
24th January 2018, 11:58 AM
Thanks GarryCol, I have read today about the location to put the -Ve lead, not on the battery.
When we jump started the car I did actually connect the -Ve directly to the battery. What risks were I running? Gulp ...
AGRO
24th January 2018, 12:18 PM
Turning internal lights off whilst camping is one method of minimising battery use. However, probably the greater current draw over time is frequent door opening. Every time a door is opened the cars system initialises expecting to be started. Leaving one door ajar while camping allows the vehicle to shut down electronically. This may be significant if you have several passengers accessing the vehicle just to get to their toothpaste, drink bottle or iPad.
A healthy battery also helps.
101RRS
24th January 2018, 01:50 PM
What risks were I running? Gulp ...
Nothing - car systems if on may misread voltages etc while charging  - don't over think things.
Kidbeen
24th January 2018, 03:05 PM
Turning internal lights off whilst camping is one method of minimising battery use. However, probably the greater current draw over time is frequent door opening. Every time a door is opened the cars system initialises expecting to be started. Leaving one door ajar while camping allows the vehicle to shut down electronically. This may be significant if you have several passengers accessing the vehicle just to get to their toothpaste, drink bottle or iPad.
A healthy battery also helps.
What makes and models are you talking about here? I never knew my car expected to be started when I opened a door.
DiscoMick
24th January 2018, 06:41 PM
Hi All, twice over the last. fortnight we have now had a flat battery whilst camping in our 2008 D3. My guess is opening and closing doors too much! 
Either way I understand that I should properly charge the battery. I have a Project IC1500 for my Camper trailer and it looks like it would do the job.
https://www.projecta.com.au/battery-charger-products/12v-automatic-15a-7-stage-battery-charger (http://archive.boston.com/yourtown/malden/articles/2011/11/20/take_care_when_jump_starting_battery_or_risk_fryin g_cars_computers/)
I am concerned though about frying electrics. There is so much talk out on the internet.
My understanding is - pick the right battery type, connect the cables in the correct order then turn the charger on.
I am also not sure which charge rate I should use, the table on page 10 refers to AH, I assume that would be Amp Hours?
Is that right.
Am I missing something significant?
If your Projecta has an auto function on it then just set it to auto and leave it to do the job. A multi-stage charger will test the battery as it charges. When it is almost charged it will step down the charge rate. Eventually it will decide the battery is charged,  stop charging and periodically wake up and test the battery to see if it needs a boost. That's how my Projecta works
BobD
24th January 2018, 07:43 PM
What makes and models are you talking about here? I never knew my car expected to be started when I opened a door.
The cars in this section of the forum, D3's and D4's!
The car wakes up and readies everything for starting if necessary. It doesn't actually have to be started but does take power to do this checking and waking up. When the parking brake symbol goes off, assuming the parking brake is on, the car has gone back to sleep.
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