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Apparently not, you need to charge them separately. The charging posts in the engine compartment are for the main battery, located behind the back wall in your trunk (your car is a 2007). To charge the auxilliary battery, the small one in the engine compartment you need a Battery Tender connected to it.
if you connect it the correct way it will charge the rear - if you only go to front battery posts it will not behave
No one should these days connect direct to the posts.... cars burn so much power with the key off - you need to move to an intelligent modern charger and give things a chance by connecting using the correct points under the bonnet which aim to understand the drain - it has a longer unthreaded brass portion for the Positive connector to go on, for either the early or later cars
early cars with both front and rear batteries positive here and negative to battery post
later single battery connection positive as below and it should have a dedicated negative post (early cars don't have) on the inner wing
if you connect it the correct way it will charge the rear - if you only go to front battery posts it will not behave
No one should these days connect direct to the posts.... cars burn so much power with the key off - you need to move to an intelligent modern charger and give things a chance by connecting using the correct points under the bonnet which aim to understand the drain - it has a longer unthreaded brass portion for the Positive connector to go on, for either the early or later cars
early cars with both front and rear batteries positive here and negative to battery post
later single battery connection positive as below and it should have a dedicated negative post (early cars don't have) on the inner wing
pdf is for the early cars
.
I don't have a battery drain, however sometimes the car won't be used for 2-3 weeks so I would like to keep BOTH batteries topped off. Can I do that with one charger/maintainer?
You don't need to.
All the idle power used by the car will be taken from the big battery in the trunk.
The small starter battery is not used at all (except for starting the car)
I don't have a battery drain, however sometimes the car won't be used for 2-3 weeks so I would like to keep BOTH batteries topped off. Can I do that with one charger/maintainer?
everyone has battery drain... for starters the entire car remains awake with key off for 7 minutes, then time and temps sap power - and on modern cars alarms eat power for fun...
Buy two brand new batteries - fully charge and refit, then leave the car locked for 2 months and see if it will go - might just start - now run diagnostics the flat rear one with throw entire car in a tail spin....
Apparently not, you need to charge them separately. The charging posts in the engine compartment are for the main battery, located behind the back wall in your trunk (your car is a 2007). To charge the auxilliary battery, the small one in the engine compartment you need a Battery Tender connected to it.
Originally Posted by BOTUS
if you connect it the correct way it will charge the rear - if you only go to front battery posts it will not behave
No one should these days connect direct to the posts.... cars burn so much power with the key off - you need to move to an intelligent modern charger and give things a chance by connecting using the correct points under the bonnet which aim to understand the drain - it has a longer unthreaded brass portion for the Positive connector to go on, for either the early or later cars
early cars with both front and rear batteries positive here and negative to battery post
later single battery connection positive as below and it should have a dedicated negative post (early cars don't have) on the inner wing
pdf is for the early cars
.
Thank you both for the input, I understand how it works.
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