Battery maintainer question

[OldGuyNewJeep]

@johnbyron - A 5 amp smart-sense maintainer will work but the jury is still out on if it can preserve battery capacity. The 10 amp does better and *should* net longer battery life. Anything higher than 10 amp is fine but the extra capacity is pretty unused in most cases.

Lastly, there is no need to separate/isolate or do anything fancy when attaching the maintainer. Positive as close to the B+ post you can, Negative as close to the B- post. Just like you’d jumpstart something.

To add to this, if ever a person plans to replace the stock battery with something bigger and better (Odyssey, Full River, etc.) then > 10a will not be wasted.

Enersys recommended their OBC-20a for my group 98 Odyssey battery. No regrets, it’s very thorough (6 stages).

I am also a Noco fan. Very versatile and handles lithium (which I have on my generator).

I bought both.

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[SteadyC]

I got curious about which I am using, my Noco is 3.5 amp G3500, been using it for years with no issues. My experience would say a 5 amp is fine.

 

[mdaitcjl]

Late to the party - I mounted a magnetic coupler to the front bumper. I went the magentic route, since it will disconnect if we forget to unplug it...

I use a Tecmate Optimate 7 Select. The connector is wired the main terminals.

 

[BRuby]

Separate the batteries and smart charge each one to prevent parasitic drain and get the proper smart charge profile. Both oem 2018 batteries still going strong and have been load tested by the dealer. Works a charm. Daily use 6 smart charges. 4 noco 2 ctek. 24/7.

https://www.jlwranglerforums.com/fo...y-battery-charging.33802/page-21#post-1718501

 

[VKSheridan]

You can isolate them. You can remove them. You can pull a ton of cables but why? None of that is needed by the alternator to keep them charged, it isn’t needed by a maintainer.

Ponder what you’re doing to the rest of your system when you frequently remove and restore their voltage source……

 

[OldGuyNewJeep]

You can isolate them. You can remove them. You can pull a ton of cables but why? None of that is needed by the alternator to keep them charged, it isn’t needed by a maintainer.

Ponder what you’re doing to the rest of your system when you frequently remove and restore their voltage source……

You mean to say we should trust the geniuses who thought wiring two differently sized batteries in parallel was OK? They charge them together via the alternator, so we should too?

That’s a no from me, dog.

They needed a cheap way to adhere to CAFE and couldn’t give two shits for how long these batteries last. Most folks end up in Jeep service departments for everything, whether that’s six quarts of oil or a crappy battery.

To each his own, but I bypassed that silly power sport battery and charge it separately. (I didn’t physically remove it because it could serve as a built-in jump pack in a pinch.) Even with a stock setup I’d be disconnecting that AUX negative and charging each battery separately.

 

[VKSheridan]

You mean to say we should trust the geniuses who thought wiring two differently sized batteries in parallel was OK? They charge them together via the alternator, so we should too?

That’s a no from me, dog.

They needed a cheap way to adhere to CAFE and couldn’t give two shits for how long these batteries last. Most folks end up in Jeep service departments for everything, whether that’s six quarts of oil or a crappy battery.

To each his own, but I bypassed that silly power sport battery and charge it separately. (I didn’t physically remove it because it could serve as a built-in jump pack in a pinch.) Even with a stock setup I’d be disconnecting that AUX negative and charging each battery separately.

Nah. Not saying you should trust anything/anyone. Just saying a D-Cell battery looks the same as AAA battery in the eyes of a charger. Both are 1.5 volts but one is taller and fatter but as we have learned from physics, electrons don’t discriminate. ?

 

[BRuby]

Just Google “charging dissimilar batteries in parallel”. Let us know which battery manufacturer recommends this.

Is pretty universal and clear that one should always smart charge dissimilar batteries separately. Otherwise you run the risk of killing your batteries prematurely. Stellantis in their design protocol simply cheaped out by putting in the lower cost lower amp-hr aux. Tons of reports here about dead aux and or dead main batteries.

Yes it is way easier to plop on and charge them both together. But not really ever recommended by any manufacturer. Stellantis in their wisdom says not to charge them at all. Just leave them uncharged. Haha with that BS!

https://www.optimabatteries.com/experience/blog/can-i-connect-dissimilar-batteries-in-parallel

 

[InjectedCJ7]

OK, a little update and a few questions. I haven’t been driving my Jeep a lot recently. Even though it’s technically my daily driver, being retired, we don’t drive nearly as much as we used to. Also, it’s been in my garage quite a bit lately, to install the RSE step sliders, trailer hitch, and the AUX switch kit. I had the battery disconnected for much of this work. So, during the last couple of trips, about 15 to 20 miles each, the ESS has displayed either battery charging, engine temperature too low, or Battery Protection Mode. I should add that I hate stop/start, and intend to shut it off as soon as I get my Tazer. After reading all 36 pages of the thread on disconnecting the AUX battery, adding the N1 N2 jumper, etc, my concern is whether my batteries (main and/or AUX) are on their way out. So, I measured the composite voltage, not running, and it was about 12.5v. I disconnected the AUX ground and measured them independently. Both were about 12.51v or 12.52v. Next, I put my battery charger (set to 2 amps) on the AUX battery, and after about an hour, it showed a full charge. I measured it at 12.8v. Then I charged the main battery, also at 2 amps, and it took between 2 and 3 hours to show full charge. It also measured 12.8v. I went for a drive, and the ESS worked properly. The voltmeter was reading between 13.1v and 13.2v for all driving conditions, around town and highway.

So, with all of this rambling explanation, does anyone have any thoughts to share About my batteries?

Thanks,
John

 

[johnbyron]

So, with all of this rambling explanation, does anyone have any thoughts to share About my batteries?

My ESS would always show "battery charging" unless I drove for hours. I then replaced both batteries and now I can not drive the car for up to 7 days and the ESS is still ready as soon as the engine reaches temperature. Try to see how long the ESS is ready for after the full charge you gave it, if doesn't last more than 1-2 days, your batteries might need to be replaced at some point.

 

[VKSheridan]

Just Google “charging dissimilar batteries in parallel”. Let us know which battery manufacturer recommends this.

Is pretty universal and clear that one should always smart charge dissimilar batteries separately. Otherwise you run the risk of killing your batteries prematurely. Stellantis in their design protocol simply cheaped out by putting in the lower cost lower amp-hr aux. Tons of reports here about dead aux and or dead main batteries.

Yes it is way easier to plop on and charge them both together. But not really ever recommended by any manufacturer. Stellantis in their wisdom says not to charge them at all. Just leave them uncharged. Haha with that BS!

https://www.optimabatteries.com/experience/blog/can-i-connect-dissimilar-batteries-in-parallel

I truly doubt we’ll ever find a battery manufacturer recommending anything that conflicts with their agenda to sell batteries let alone dispel myths that help drive them sales….Heh heh

Because this is a fun conversation, let’s keep this going:

Unless our Jeep is a hardcore garage queen, it’s probable our alternator puts more current into our batteries at a far more sustained frequency and duration then our maintainers. But let’s ignore that since battery salesfolk don’t mention that.

That said, we agree to maintain/tender our batteries isolated and independent of each other. We smugly connect the maintainers while laughing about the ignorance of that VK moron in the forum and we let that maintainer magic happens……

But then we pause.

We ask ourselves, “What happens when we connect these two beautifully charged batteries together?”

The electrons rush to gossip about their time apart and all their “dissimilarities” vanish as they rebalance into a single combined voltage. (They have to because they’re connected)

And they will swap spit, errrr, electrons until we disconnect them again, maintaining voltage balance.

Everything we hoped to accomplish by maintaining our batteries separately is undone the instant they are connected.

A kid rides by on his bike and says, ”Charging isolated doesn’t get rid of dissimilarities, it actually emboldens them”.

Should we punch the kid and steal his bike or ?

 

[BRuby]

Def you do you. Pretty sure most all of us are perfectly fine with that - including any battery manufacturer or Stellantis. More battery sales for all of them. They will thank you.

But since virtually all battery manufacturers are telling you to “not connect dissimilar in parallel’ - they are helping you - to not buy “more batteries”.

Stellantis on the other hand wants you to buy more of their batteries. By hooking up the alternator to charge them in parallel - which no one recommends. Then telling you to store them disconnected and let them sit uncharged - which no one recommends. Is complete 100% stupidity.

Stellantis cheaped out. Simple as that. That is why you now have third party companies changing the idiotic Stellantis battery design to include similar identical batteries. Now here you can charge them in parallel without the typical dissimilar battery issues. Makes sense.

 

[WranglerMan]

Lower current chargers will work just fine. They just take longer to charge. The voltage has nothing to do with the current. It will reach voltage, but is current limited. Not a problem, just slower.

Yes sir they will work fine but only and I say only after doing a proper charge, I spent months talking with and emailing lots of battery makers and they all have different opinions on battery maint but they all agreed that these little maintainers do more harm than good when used improperly.

There are basically 6-7 stages of charging but for the sake of argument let’s say there’s three as that’s what most know.

1. Bulk charge

2. Absorption/Float

3. Maintain

The bulk charge does most of the heavy lifting and needs to be above 14 volts but under 16 for AGM batteries as this serves to speed up the charge process but almost do most of the work of removing any sulfites built up on the battery plates.

The next stage is where the conditioning comes in and with these newer vehicles with all their wiring and parasitic draws when a charger say only puts out 13-13.5 with 1-2 amps its a slow death for batteries per the techs i talked with because lower voltages push less amps and with the resistance of the wiring coupled with parasite draw it’s a no win situation.

The last stage is maintain and this is where one could use a maintainer but only after the initial stages are done and can be left connected long term but things like the IBS which periodically wake up the ECM/ECU to do battery analysis take a small toll on the battery over time and if you have other items that parasitically draw on the power it’s even worst.

The best anyone can do is contact the maker of there battery and get there advice and also just look at charging curves for Full River, Odyssey, North Star etc.. and see what the curve looks like

I have two 64 aH Full River 750’s and heavy parasitic draw due to my setup so I recently started looking at ways to cut back on my power consumption on the downtime to extend my battery life and by accident I discovered that disabling the IBS thru JSCAN has benefitted me while still maintaining the smart charging function.

I am no engineer and no scientific background but do know that batteries are expendable but after spending the $$ I spent on batteries I wanted to be more educated on there upkeep so that’s when my OCD kicked in.

The small 1.25 amp tender I used when I first got my 2018 is long gone and I now use a NOCO 10 weekly and then use my 6 stage 20 amp Odyssey monthly for a deep cycle conditioning and after my recent changes in addressing parasite draw my worries are slowly disappearing.

 

[VKSheridan]

Def you do you. Pretty sure most all of us are perfectly fine with that - including any battery manufacturer or Stellantis. More battery sales for all of them. They will thank you.

But since virtually all battery manufacturers are telling you to “not connect dissimilar in parallel’ - they are helping you - to not buy “more batteries”.

Stellantis on the other hand wants you to buy more of their batteries. By hooking up the alternator to charge them in parallel - which no one recommends. Then telling you to store them disconnected and let them sit uncharged - which no one recommends. Is complete 100% stupidity.

Stellantis cheaped out. Simple as that. That is why you now have third party companies changing the idiotic Stellantis battery design to include similar identical batteries. Now here you can charge them in parallel without the typical dissimilar battery issues. Makes sense.

Because the average consumer struggles separating ads from information (to the extent they actually think the seller is trying to convince the consumer not buy their product/solution), misinformation thrives.

Resistance is resistance. A maintainer nor an alternator knows if the resistance to flow is from age or saturation. Capacity or brand. AGM or SLI. Nope, they just know the sum of resistance between B+ and B- is “X” and at 12 VDC, the maximum flow of “Y” is limited by their rating and Ohm’s Law.

Electricity is like water, it flows to the path of least resistance. Two batteries in parallel are like two potholes side by side in the rain. The little pothole doesn’t fill first and leave the deep one empty or get full and then watch the deeper one fill. They fill together. Even if one is in concrete and the other in porous asphalt. As long as they are connected, they will fill at the same rate. The age of either pothole or who made them means nothing to the rain cloud.

Trailer brake batteries have been smaller in size, capacity, composition, amp hour rating and serviceability since they were first introduced. History (not marketing or blog rhetoric) has proven they don’t get junked if connected and charged in parallel with vehicle’s single or dual batteries.

In fact, “dissimilar“ batteries exist in a range of things like ice chests, APU’s, jumpstart packs, portable DVD players, your impact wrench, your Garmin, your iPhone, your Bluetooth earpiece and any battery you connect to your electrical system for a charge. As long as they see the proper voltage, life’s good, no need to isolate ‘em.

I am curious why you think what you think though. Physics don’t appear to back it, history and current applications don’t seem to back it. What has convinced you two batteries connected in parallel must be isolated to properly charge indifferent to so many real world examples that suggest the contrary?

I mean no disrespect, I am genuinely curious and hoping we can keep exchanging enjoyable dialogue.

@WranglerMan, I’m with you on the “lil tricklers“. Their track record on maintaining something as simple as an emergency floodlight doesn’t seem all that great. Being no math major, I can’t get the math to suggest that low of flow can net much more than a surface charge. Maybe someone else can enlighten me on them critters.

 

[BRuby]

No disrespect taken. But probably is best at this point that you spend some time to enquire at Optima or NOCO or CTEK or Odyssey and other battery manufacturers directly for more information to satiate your queries. Then report back their reasoning why they recommend not to charge dissimilar batteries in parallel.

This email excerpt was sent to me from my dealer after they contacted FCA internally after I questioned the FCA practice of not charging stored batteries at all:

“Best to remove both batteries and run a trickle charge on them both separately, prefer if he purchased one of the Mopar ones, but most safety trickle charges with dummy proof settings will work.”

This was posted by me a while back as well. Topic has been well hashed.

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