Acura MDX SUV Forums banner

1 - 7 of 7 Posts

·
Registered
Joined
·
713 Posts
Discussion Starter #1
I've noticed that my 2015 SH-AWD MDX has a new lag when I press the starter button. Last time this happened the battery was bad. This battery in it is less than 3 months old. I've seen threads here where folks say that the alternator does not fully charge the battery but that sounds kinda like a wives' tale to me. That said, is there any evidence that 3rd gen alternators turn off early on charging a battery/ I am puzzled by this new 3 or 4 second delay when starting even though my foot is clearly on the brake pedal. The MDX has 33,000 miles on it.
 

·
Registered
Joined
·
1,952 Posts
I've noticed that my 2015 SH-AWD MDX has a new lag when I press the starter button. Last time this happened the battery was bad. This battery in it is less than 3 months old. I've seen threads here where folks say that the alternator does not fully charge the battery but that sounds kinda like a wives' tale to me. That said, is there any evidence that 3rd gen alternators turn off early on charging a battery/ I am puzzled by this new 3 or 4 second delay when starting even though my foot is clearly on the brake pedal. The MDX has 33,000 miles on it.
It's a fact that Acura programming does not fully charge the battery. The alternator is not always charging... Instead, the ECU monitors several variables and will command the alternator to run at a specific duty cycle, as necessary, to maintain an acceptable charge (not 100%).

That said, the system is designed to leave reserve capacity to start the vehicle, and a 3-4 second delay is not normal. Is this a delay between pushing the button and the starter cranking? Or does the starter engage immediately, and it take 3-4 seconds of cranking for the engine to start and run on it's own?
 

·
Registered
Joined
·
550 Posts
Its always possible you got a bad battery. Take it to a real battery store and have it load tested. That will tell you if you have a battery or something else going on.
 

·
Registered
Joined
·
713 Posts
Discussion Starter #4
It's a fact that Acura programming does not fully charge the battery. The alternator is not always charging... Instead, the ECU monitors several variables and will command the alternator to run at a specific duty cycle, as necessary, to maintain an acceptable charge (not 100%).

That said, the system is designed to leave reserve capacity to start the vehicle, and a 3-4 second delay is not normal. Is this a delay between pushing the button and the starter cranking? Or does the starter engage immediately, and it take 3-4 seconds of cranking for the engine to start and run on it's own?
push button and wait 3 - 4 seconds then it cranks and starts right away.

Would it hurt to put a modern maintenance charger on it over night (CTEK MXS 5.0)? This is one that is designed to properly cycle the battery to a 100% charge then cut off. I have one that has a spare hook up that can be fed up above the battery..
 

·
Registered
Joined
·
157 Posts
push button and wait 3 - 4 seconds then it cranks and starts right away.

Would it hurt to put a modern maintenance charger on it over night (CTEK MXS 5.0)? This is one that is designed to properly cycle the battery to a 100% charge then cut off. I have one that has a spare hook up that can be fed up above the battery..
I use a 5 amp Bettery Tender unit on my 2018 Hybrid whenever it's in the garage and I know that I'm not going to be using it in the next three or four days. These B.T. units not only charge the battery fully, they responsively keep it at full charge, but not with a constant trickle charge. I highly recommend them. I'm not sure that this will correct your problem though. On my car, when I touch the start button, there is usually a one or two second delay, which I've accepted as normal (you know, the computer's thinking about it). Four seconds sounds like a bit much.
 

·
Registered
Joined
·
1,952 Posts
Would it hurt to put a modern maintenance charger on it over night (CTEK MXS 5.0)? This is one that is designed to properly cycle the battery to a 100% charge then cut off. I have one that has a spare hook up that can be fed up above the battery..
I have a battery tender that I use on my MDX. I learned, long ago, that maintenance chargers keep my motorcycle batteries happy and greatly extend their service life, so I’ve adopted the same methodology for my other vehicles.
 
  • Like
Reactions: djlandkpl

·
Registered
Joined
·
157 Posts
I have a battery tender that I use on my MDX. I learned, long ago, that maintenance chargers keep my motorcycle batteries happy and greatly extend their service life, so I’ve adopted the same methodology for my other vehicles.
Yes, the battery life is greatly extended. I have a 2008 BMW 750, and I have used a Battery Tender almost since new. It still has the original factory battery, and the battery still cranks the engine at full speed on a start. I've seen no behavior that suggests on its way out. My favorite independent BMW mechanic tells me that he's seen batteries that are kept on a Battery Tender last 10 or 15 years. On other BMWs, he says, the life is about four years. Here's one:

https://www.amazon.com/Battery-Tender-022-0186G-DL-WH-12V-Charger/dp/B00EDFPN1O/ref=sr_1_1_sspa?ie=UTF8&qid=1533699929&sr=8-1-spons&keywords=battery+tender+5+amp&psc=1
 
1 - 7 of 7 Posts
Top