Battery care, don’t drive it much question...

[Resin Addict]

So this whole automatic stop start, double battery issue is new to me, and this will be my first winter with the JL having bought it in June.
I live in Michigan, my wife is currently stationed in AZ, so during the winter I work remotely and spend two weeks each month in AZ, so the Jeep will be parked in my cold garage not running or being started for that length of time.
In addition, I work from my home (have been for more than 10 years now), and try to limit the amount of going out anyway, so at the most, when I’m home those two weeks a month in the winter, I probably only put about 100 miles or less a week on my Jeep.
I’ve always kept one of the “Battery Tender” smart chargers on my ‘59 pickup over the winter, and that’s worked great, should I do the same on my JL, especially for those 2 weeks I’m gone every month?

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[Heimkehr]

There were and are periods when my truck, and my daughter's SUV, sit undriven for one to a couple of weeks at a time, for varying reasons.

Battery Tenders (of which I own 3) weren't ever connected to those vehicles' batteries, even when we knew they'd be sitting for a little while. At no time was their cranking power diminished to a degree that could be walked back to said periods of inactivity.

My truck was garage-kept, whereas my daughter's SUV is parked outside as I type this post. Pennsylvania gets just as cold, if not a bit colder, than Michigan in the winter.

As your Jeep is being driven semi-regularly (+/- 100 miles weekly not really being an insignificant number, either), I'd suggest you have the option of not using a battery maintainer, with no anticipated ill effects. Just my thoughts based on similar experience.

 

[631_Islander]

So this whole automatic stop start, double battery issue is new to me, and this will be my first winter with the JL having bought it in June.
I live in Michigan, my wife is currently stationed in AZ, so during the winter I work remotely and spend two weeks each month in AZ, so the Jeep will be parked in my cold garage not running or being started for that length of time.
In addition, I work from my home (have been for more than 10 years now), and try to limit the amount of going out anyway, so at the most, when I’m home those two weeks a month in the winter, I probably only put about 100 miles or less a week on my Jeep.
I’ve always kept one of the “Battery Tender” smart chargers on my ‘59 pickup over the winter, and that’s worked great, should I do the same on my JL, especially for those 2 weeks I’m gone every month?

I think 2 weeks is not bad and you may not discharge your battery significantly given the fact that the Jeep will still be driven for the balance two weeks. But to be safe, you can always disconnect the batteries.

I am kind on the same boat as you. I got my 4 door in Sept 2019 and have only put on 5300 Miles so far. I have never had a battery issue yet. I do however always turn off my ESS every time I enter my Jeep.

 

[jeepoch]

Hi Randy,

Great post, good questions. From my experience, yes a battery tender is a very good idea. But use a good one. Something that will sufficiently charge (with ample current), then be able to trickle charge when required and finally be able to shut off completely when necessary. Also recall that the JL actually has two dissimilar batteries connected in parallel making the tender's job that much more difficult.

I too seemed to be having battery issues. Recently brought my Sport into the dealership to have my charging system checked and batteries 'load' tested because I was getting intermittent "Battery Protection Mode" warnings. I drive my JL quite a lot but only fairly short trips or off-roading near home typically in 4Lo at very low speeds.

The dealership reported that all was well.

Clearly however I was not giving my system enough time to charge the batteries sufficiently even with my EVIC showing the voltage consistently at 14.5v or higher.

My wife and I recently drove from our home north of Denver straight through to Big Bear Lake CA. Drive time 17 hours total. Stopping only for gas three times.

Only near the very end of the trip did my EVIC display eventually drop into the low 13v range. So almost an entire day of constant driving at 70mph did my batteries eventually charge.

So a tender is probably a very good idea. I'll report back on the one I eventually settle on if your interested. Clearly my normal (typical) driving routine is insufficient at charging my batteries. I drive my Jeep every day.

Jay

 

[BrntWS6]

This is what I did. A bit over the top but a clean setup if you are a DIYer. And really not that hard at all.

https://www.jlwranglerforums.com/fo...arger-mount-inlet-install-lots-of-pics.44466/

 

[OldGuyNewJeep]

I’ve always kept one of the “Battery Tender” smart chargers on my ‘59 pickup over the winter, and that’s worked great, should I do the same on my JL, especially for those 2 weeks I’m gone every month?

100% yes. Just search this forum for “battery.” Pair the fact that having two differently sized batteries wired in parallel with the fact that FCA sources the cheapest ones they could get away with and the MTTF is short. That is to say, as soon as one battery will no longer hold its charge it will take the other down with it.

Anyway, yes, a good old Deltran Battery Tender is a wise investment. I use mine 2x a month.

Recently, I implemented Jerry’s fantastic AUX battery bypass:

https://www.jlwranglerforums.com/forum/threads/3-6l-ess-aux-battery-bypass.17293/

With the bypass jumper in place and a cheap battery switch on the AUX negative, I no longer need to worry about the batteries draining each other. (I use a Tazer to automatically disable ESS.) My AUX is now just an on-board emergency backup. I still top them both off with my tender 2x a month.

 

[Gee-pah]

100% yes. Just search this forum for “battery.” Pair the fact that having two differently sized batteries wired in parallel with the fact that FCA sources the cheapest ones they could get away with and the MTTF is short. That is to say, as soon as one battery will no longer hold its charge it will take the other down with it.

Anyway, yes, a good old Deltran Battery Tender is a wise investment. I use mine 2x a month.

Recently, I implemented Jerry’s fantastic AUX battery bypass:

https://www.jlwranglerforums.com/forum/threads/3-6l-ess-aux-battery-bypass.17293/

With the bypass jumper in place and a cheap battery switch on the AUX negative, I no longer need to worry about the batteries draining each other. (I use a Tazer to automatically disable ESS.) My AUX is now just an on-board emergency backup. I still top them both off with my tender 2x a month.

I like this @OldGuyNewJeep even if it's not for me as I still try to use ESS.

How you set this up is clearly a lot about personal taste, but if it were me I might put a shore charger in the engine bay, connected to both batteries, even if the ESS/Aux battery is isolated. I'm sure you've thought out what's best for you.

I like your idea of the ESS/Aux battery being your "backup battery."

Cheers.

 

[Gee-pah]

@Resin Addict Hey Randy:

Yes.

The combination of infrequent use, late model electronics that will pull small amounts of power, the loss of current in infrequently used batteries--particularly in cold weather, and the temperamental nature of the design of the battery system in the 3.6L JL, IMHO, make it a slam dunk that you're best having the vehicle on a trickle charger.

I'm using my 3.6L JL less simple because of COVID and do this. I've had to do this before COVID to keep ESS running (no, the irony is not lost on me that to be green and use ESS I have CO2 emitting utility generators providing me with power to run my trickle charger.)

(Fairness to facts: I also run a 4.5W dash camera in parking mode, but this post applies to all.)

I noticed that you have a 2018. This model year's 3.6L will NOT crank, short of some DIY workarounds, or dealer modifications, or 3rd party solutions (Genesis battery system) if the ESS/Aux battery lacks sufficient power.

Arguably the main battery could have all the power in the world; the 2018 3.6JL won't (even attempt a) crank (short of the fixes described below) if the ESS/Aux battery lacks adequate charge: even though both batteries are connected in parallel if this test of the ESS/Aux battery is passed, and used together to crank the engine.

There are workarounds on this board, one was alluded to above by @OldGuyNewJeep , that either connect both batteries in parallel 100% of the time (they're in parallel 99.9% of the time but for an instant at cold crank and ESS events) or take the ESS/Aux battery out of the picture all together (not suggested if you want to run ESS), and there is a flash by the dealer (PCM update TSB 18-092-19 ) that will switch the 3.6L JL to the main battery at crank time if the ESS/Aux battery fails, rather than strand the motorist....

...none of these by the way being a replacement for trickle charging.

This logic change the flash provides is part of model year 2019 3.6L JLs and newer.

 

[WranglerMan]

Trickle charge when you can, I still do weekly top offs when it’s parked for several days even with my new setup, the best advice I can offer is do your homework on the batteries you plan on running, not all chargers are equal, yes they all charge but they all don’t charge correctly for the batterie(s) you are running.

These batteries all have different charging demands, some like to be charged low and slow others like to be put thru a reconditioned cycle periodically to keeps things flowing as designed.

Batteries are an expendable item on any vehicle and they don’t last forever but we have to take care of them to get the most we can from them, I for one will do my best to keep mine at peak charge as they only have so many cycles so I will following what Full River wants me to do and hope for the best.

 

[Resin Addict]

So...figured I’d give an update...
Since I’m familiar with the “Battery Tender” smart charger that I use on my ‘59 Apache over the winter, I went ahead and bought another one of those.
Ive been driving the JL the normal amount (for me) over the last couple weeks, but when I hooked it up yesterday, the charger indicator lights showed steady red, indicating that the batteries were less than 80% and the tender was charging them. One thing I failed to mention also, was that when I bought the JL last Spring, it had sat on a lot for a couple months over the winter, and eventually after I’d had it for about a month, the batteries failed, (first the auxiliary and then the primary), so both batteries were replaced with new batteries (under warranty) by the Dealer this past summer.
After being connected to the “Battery Tender” for about 2 hours, the green light started flashing while the red light remained steady, indicating that the batteries were now between 80 and 100%, and after another 2 or 3 hours, the red turned off and it’s now solid green indicating that the ”Battery Tender” believes the batteries are at full charge.
I did find it interesting that “my” normal amount of driving does not appear to be enough to keep the batteries charged To what is considered 80%.
I think hooking it up to the tender may become a regular habit for me.
in my case, I hooked the quick connect plug up to the primary battery terminals, so I’ve got a pigtail that’s “permanently attached, and I’m probably going to mount the “Battery Tender“ on a shelf on the garage ceiling with the cable hanging down, and let the JL’s open hood remind me that the cable is connected.

 

[Heimkehr]

The Deltran Battery Tenders have limited charge rates, insomuch that their mission brief is to intelligently monitor and maintain fully charged batteries. Said differently: the Plus's output is a modest 1.25 amps, and the Juniors provide a miniscule 750 or 800 mA, depending on the model.

Connecting any of the foregoing to a full size automotive battery, even one in good health, will require a bit of time to allow the charger's indicator bulb(s) to progress from solid red to red/flashing green to steady green. The amount of time needed for the light progression, sometimes measured in hours, isn't necessarily an indicator of a battery being in marginal health or requiring longer driving time. The same or similar amounts of time are needed when I connect one of my Tenders to my 12V riding mower battery (as it is as I type this post).

Only when I connect a Tender to a comparatively small powersports battery, like in either of my two motorcycles, will the aforementioned red/green light progression occur at a fairly rapid pace. Again, this is a function of battery size.

It's nothing to worry about, absent direct indications of compromised battery health.

 

[Resin Addict]

The Deltran Battery Tenders have limited charge rates, insomuch that their mission brief is to intelligently monitor and maintain fully charged batteries. Said differently: the Plus's output is a modest 1.25 amps, and the Juniors provide a miniscule 750 or 800 mA, depending on the model.

Connecting any of the foregoing to a full size automotive battery, even one in good health, will require a bit of time to allow the charger's indicator bulb(s) to progress from solid red to red/flashing green to steady green. The amount of time needed for the light progression, sometimes measured in hours, isn't necessarily an indicator of a battery being in marginal health or requiring longer driving time. The same or similar amounts of time are needed when I connect one of my Tenders to my 12V riding mower battery (as it is as I type this post).

Only when I connect a Tender to a comparatively small powersports battery, like in either of my two motorcycles, will the aforementioned red/green light progression occur at a fairly rapid pace. Again, this is a function of battery size.

It's nothing to worry about, absent direct indications of compromised battery health.

I should also add that the “Battery Tender” I bought was the “Plus” model, but your explanation is reassuring.

 

[WranglerMan]

@Heimkehr this was a great explanation on the Deltran or similar, @Resin Addict i use a Tender + on my wife’s 2020 Jag as it sits alots and even after it’s solid green for days and we take it our for the afternoon when I get home I put it back on the tender and it’s solid red for several hours before flashing and then a few more hours solid green.

You have to understand maintainers like the 1.25 Deltran are slooooo to charge and also understand that these newer vehicles all have a certain amount of parasitic draw that keep pulling our batteries down and it takes time to bring back up from that drain with a small tender, heck just cranking the engine a few times during the day running errands will suck a lot of juice from the batteries that the alternator will struggle to put back unless it’s a long drive just letting it idle for 5-10 mins does little to put back what you would lose just by starting it a few times.

If you want fast buy more amps in a charger and if you are in no hurry buy something smaller but also do your homework on the types of batteries you are charging as all chargers are not meant for all batteries, yes it will charge them but charging correctly is just as important as keeping them charged.

I contacted the maker of my batteries and told them what I was planning on using and they were super polite and highly recommended I go a different route so then I started looking at charging curves and length of time at a certain voltage and it all got very interesting so back to the makers of my dual battery system and also several more conversations with Full River battery and also numerous calls with Deltran, NOCO and Odyssey and after doing my homework and getting good solid info from several sources I do a weekly top off with a 10 amp NOCO and then a monthly reconditioning with a multistage 20 amp odyssey and my batteries seem to like the extra attention and my JL seems electrically so much happier having two identical batteries that get charged that same way.

 

[thewise1]

The message "battery saver on some systems may have reduced power" came on the dash briefly the other day. (Got 20,000 miles or so on a 2018 JL with the 4 cylinder Turbo - not used much). So went out to the barn and found an old Deltran trickle charger. It worked overnight in the garage and the charger finally came back to green. Next step, tomorrow, look for a new NOCO Genius2d as a dedicated replacement charger. Kind of glad the issue came up - found that the mice have started eating the hood insulation. Going to try some Tomcat Repellents Rodent Spray. Maybe a good time to spray wash the engine and replace the cabin air filter too. Thanks for the charger ideas above.

 

[krel1]

Hi Randy,

Great post, good questions. From my experience, yes a battery tender is a very good idea. But use a good one. Something that will sufficiently charge (with ample current), then be able to trickle charge when required and finally be able to shut off completely when necessary. Also recall that the JL actually has two dissimilar batteries connected in parallel making the tender's job that much more difficult.

I too seemed to be having battery issues. Recently brought my Sport into the dealership to have my charging system checked and batteries 'load' tested because I was getting intermittent "Battery Protection Mode" warnings. I drive my JL quite a lot but only fairly short trips or off-roading near home typically in 4Lo at very low speeds.

The dealership reported that all was well.

Clearly however I was not giving my system enough time to charge the batteries sufficiently even with my EVIC showing the voltage consistently at 14.5v or higher.

My wife and I recently drove from our home north of Denver straight through to Big Bear Lake CA. Drive time 17 hours total. Stopping only for gas three times.

Only near the very end of the trip did my EVIC display eventually drop into the low 13v range. So almost an entire day of constant driving at 70mph did my batteries eventually charge.

So a tender is probably a very good idea. I'll report back on the one I eventually settle on if your interested. Clearly my normal (typical) driving routine is insufficient at charging my play online casino for real money choose trusted online casino here https://sitkicker.com/ batteries. I drive my Jeep every day.

Jay

Good question and a great answer!

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