Charging A Battery Located Under The Seat ?

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My 2015 Jeep Grand Cherokee has the battery located under the passenger seat. It also has "jumper posts" located under the hood to jump start the vehicle, should the need arise. Should there be any circumstances that would prevent using a battery charger or maintainer off those same jumper posts?

Common sense would dictate no. If the jumper posts can handle a high output Lithium Ion jump starter, a charger should be no problem. But with so much electronics in these newer cars, it pays to be careful.

I was thinking of hooking up a Battery Tender, or else charge it from time to time using a charger, (15 amp). Reason being is it sits for several days sometimes, and I know it's better for batteries to remain in a fully charged state. It is a AGM battery, and from what I've read here, they like a higher charging rate than standard flooded lead acid batteries.

So..... Assuming hooking the charger up to the jumper posts, instead of directly to the battery terminals won't cause any issues or problems, what would a good charging rate be for a 850 CCA AGM battery. Thanks in advance. (The max my charger puts out is 15 amps).
 
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I know common sense in the last decade is not en vogue, but if a situation ever screamed "common sense" I believe you found it Bill. ;)
 
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My 2015 Jeep Grand Cherokee has the battery located under the passenger seat. It also has "jumper posts" located under the hood to jump start the vehicle, should the need arise. Should there be any circumstances that would prevent using a battery charger or maintainer off those same jumper posts?

Common sense would dictate no. If the jumper posts can handle a high output Lithium Ion jump starter, a charger should be no problem. But with so much electronics in these newer cars, it pays to be careful.

I was thinking of hooking up a Battery Tender, or else charge it from time to time using a charger, (15 amp). Reason being is it sits for several days sometimes, and I know it's better for batteries to remain in a fully charged state. It is a AGM battery, and from what I've read here, they like a higher charging rate than standard flooded lead acid batteries.

So..... Assuming hooking the charger up to the jumper posts, instead of directly to the battery terminals won't cause any issues or problems, what would a good charging rate be for a 850 CCA AGM battery. Thanks in advance. (The max my charger puts out is 15 amps).
Use those posts, you're lucky as there are some cars where the battery is not easily accessible and no posts.
 
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OP said, "... what would a good charging rate be for a 850 CCA AGM battery...."

The PRACTICAL ANSWER to that question is to use a charger / maintainer designed for AGM batteries.

From what I've read AGMs can take the higher charging rate mentioned but in the "home stretch" AGMs need a lower charge rate. Old fashioned chargers were said to kill AGMs as they approach "fully" charged.
 
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I picked up a NOCO Genius 5 as my maintainer for the Mercedes. 800 amp AGM with remote posts, so pretty similar.
Since I was driving so little, the first time I used it it took overnight to bring it up to full charge.
These days, after sitting a week or so, it only takes a couple hours.
 
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My 2015 Jeep Grand Cherokee has the battery located under the passenger seat. It also has "jumper posts" located under the hood to jump start the vehicle, should the need arise. Should there be any circumstances that would prevent using a battery charger or maintainer off those same jumper posts?

Common sense would dictate no. If the jumper posts can handle a high output Lithium Ion jump starter, a charger should be no problem. But with so much electronics in these newer cars, it pays to be careful.

I was thinking of hooking up a Battery Tender, or else charge it from time to time using a charger, (15 amp). Reason being is it sits for several days sometimes, and I know it's better for batteries to remain in a fully charged state. It is a AGM battery, and from what I've read here, they like a higher charging rate than standard flooded lead acid batteries.

So..... Assuming hooking the charger up to the jumper posts, instead of directly to the battery terminals won't cause any issues or problems, what would a good charging rate be for a 850 CCA AGM battery. Thanks in advance. (The max my charger puts out is 15 amps).
I use a battery maintainer on my Mercedes ML because I don't drive it all the time. Works great. Also can charge on those posts.
 

billt460

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OP said, "... what would a good charging rate be for a 850 CCA AGM battery...."

The PRACTICAL ANSWER to that question is to use a charger / maintainer designed for AGM batteries.

From what I've read AGMs can take the higher charging rate mentioned but in the "home stretch" AGMs need a lower charge rate. Old fashioned chargers were said to kill AGMs as they approach "fully" charged.
My charger has a AGM setting. But I can also vary the charging rate from 2 to 8 to 15 amps.
 

billt460

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This morning I hooked up the charger and set it on AGM, at 8 amps. And ran it for 2 hours. I then hooked up the Battery Tender Jr. And it flashed green for about 10 minutes, then went to solid green, (float setting).

So tomorrow I'll test it after it settles down, and see where it's at. It should be at or near 100% charge.
 
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Just this minute I returned from "checking in" on my aged neighbors. I do light maintenance on their 2010 Accord (2.4l).

The AAA man came by to charge up their car which has been sitting. I check the battery (which I installed) occasionally and it's still good. I suppose idle time, short trips and cold weather took it down. Still, the AAA guy said the battery was OK still.

I offered to throw my charger onto the battery as many need it now-a-days. At that point the old man -they're both 87- looked tired and sank into a chair. Hey, he had just had his lungs drained this morning so I figured to get out of his face for a while.

I'll again ask him in an email tomorrow.
 
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My charger has a AGM setting. But I can also vary the charging rate from 2 to 8 to 15 amps.
AGM has lower internal resistance so can take a charge faster, but it is still better for it to slow charge, if you have the time to wait, and once it reaches float charge/maintenance charge level, around 13.0-13.2V with periodic pulses ~14.5V to maintain that, or with an analog charger just keep it at 13.0-13.2V. 2A setting is the best of the three, but too high to keep connected past 100% charge state if the charger is not accurate to terminate charge or switch to a float mode, or very long term, an even lower storage voltage as listed above.
 
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Just this minute I returned from "checking in" on my aged neighbors. I do light maintenance on their 2010 Accord (2.4l).

The AAA man came by to charge up their car which has been sitting. I check the battery (which I installed) occasionally and it's still good. I suppose idle time, short trips and cold weather took it down. Still, the AAA guy said the battery was OK still.

I offered to throw my charger onto the battery as many need it now-a-days. At that point the old man -they're both 87- looked tired and sank into a chair. Hey, he had just had his lungs drained this morning so I figured to get out of his face for a while.

I'll again ask him in an email tomorrow.
Kira, convince your agers to buy the HF 1/2 watt float charger. The one that is always on sale for $4.99. It goes to float V and then appears shut off.
 

Nick1994

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I use the posts under the hood on my 14’ Grand Cherokee. I charge once a month or so, using my Noco 10A charger on the AGM setting.

What’s nice is there’s enough room to still close the hood and the cord sticks out over the headlight. I don’t have a garage so then I don’t worry about someone taking the charger.
 
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It’s not an “ideal” connection but I don’t see why not. Just as long as the Jeep’s engine isn’t running during charging to prevent a power spike taking out any power control/body control modules.

If it was me, I’d consider using the same SAE quick-connect as a motorcycle battery charger connected to the post terminal clamps.
Kira, convince your agers to buy the HF 1/2 watt float charger. The one that is always on sale for $4.99. It goes to float V and then appears shut off.
I bought a Noco Genius 10 during Prime Day for that reason alone - it’s AGM “aware” and can do a float on those. There’s an AGM battery in two cars I care for now.
 

billt460

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I bought 2 Noco Genius 1's, and wired them to my Jeep and my Toyota. They're a nice unit. At first the unit pulsated a red LED which signifies max charge rate. (1 Amp). Then it will go to a pulsating green LED which means it's "topping off" the charge. Then it goes to a solid green LED which means it's in, "Float Mode". These units have a regular lead acid / AGM / and a Lithium Ion setting.

The "topping off" (pulsing green LED), can take up to 24 hours. But it's supposed to install a maximum charge. Which is where my Jeep is now. I just installed the wiring in the Toyota, and plugged it in about an hour ago. So it most likely will take some time. My battery tester called it, "Good Battery Needs Recharge". So now it's getting it. We'll see.
 
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No issues using the charge posts. As an AGM powered beast? Hook her up and blast it with the AGM cycle on your charger. Full beans. A battery will only really take what it needs unless you force an overcharge situation with an unregulated buzz box charger.

In doubt? Check with an ammeter and voltmeter. AGM's truly need a more aggressive charge curve, but unless neglected on charge won't blow up unless there was an egregious error. Look up specific charge cycling for your battery from the manufacturer to be dead on bawlz sure on what you should do.

The fact you simply care to standby charge it at all is more than most folks do. Go forth. Conquer winter and crank hard. 💪
 

JHZR2

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I use the underhood points for my trunk mounted battery in my 135i. My Chevy truck has side terminals, so I connect at a load center with a constant hot. No issues with either for many years.
 

billt460

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The pulsating green light on the Noco Genius 1 can take up to 48 hours to fully "top off" the batteries charge, before it goes solid green. That is because it's doing it on and off, with only milliamps. Back to the whole, "pouring the beer in the glass" analogy.

After that if you drive the vehicle, then plug it back in, the whole process starts over, and it could take another 12 hours or more before it senses an absolute, 100% full charge. Even longer with an older battery.

We're probably actually talking the last 1% or so of the charge. Something higher amperage chargers never really attain. It's not really necessary, or practical for that matter. But this charger will do it. And if the car is sitting for several days on end without being driven, it's not hurting anything having the battery charged to it's absolute full potential. And be kept in that condition.

But if I had a run down battery that needed a good solid charging, it would not be my choice. As you said, no one has the time to babysit a dead battery that won't crank.
 
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