Time it takes the alternator to fully charge a nearly dead battery

[Mister Lamb]

My work commute is just around a 10 minute drive. I haven't had the opportunity to take a nice long drive in probably a month+, so my battery has consistently been at 14.8V.

I took an 8 hour drive yesterday and at approximately hour 5 my battery's voltage finally fell below 13V.

I had my phone plugged in and the heat on @ 30% which may have contributed to longer charging times.

5 hours @ 70-90mph still seems like a long time to me, anyone know the rate at which an alternator charges a battery?

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[Hootbro]

The rate is going to vary based on what the intelligent battery sensor on the main battery detects is the discharge condition with the PCM acting as a voltage regulator telling the alternator at what duty cycle to charge the batteries.

Given it is a two battery system with a 2nd aux battery, if either or starts to get weak, it will draw the other one down also and extended battery charge times will be more common.

Seems to be more common when these vehicle hit the 3 year mark, battery issues start to become more prevalent.

 

[kevman65]

The rate is going to vary based on what the intelligent battery sensor on the main battery detects is the discharge condition with the PCM acting as a voltage regulator telling the alternator at what duty cycle to charge the batteries.

Given it is a two battery system with a 2nd aux battery, if either or starts to get weak, it will draw the other one down also and extended battery charge times will be more common.

Seems to be more common when these vehicle hit the 3 year mark, battery issues start to become more prevalent.

I'm past the 3 year mark, been waiting for a battery failure.
Been constantly at 14.3V when driving so figure it's just a matter of time.

Might go ahead and change them before it gets cold so I don't have to do it when it's 0 outside. That's the worst time to have to change batteries.

 

[Hootbro]

I'm past the 3 year mark, been waiting for a battery failure.
Been constantly at 14.3V when driving so figure it's just a matter of time.

Might go ahead and change them before it gets cold so I don't have to do it when it's 0 outside. That's the worst time to have to change batteries.

Have you thought about doing a aux battery delete?

 

[kevman65]

Have you thought about doing a aux battery delete?

Yes, and probably will. Just trying to milk everything I can out of these batteries.

I understand their thinking on lowest bidder on parts, but the warranty headaches they've had with these low grade batteries has to have ended up costing them more than they made on the deal.

Probably going with an Odyssey when I do the switch. If I do decide to keep the Aux going with a Bosch as it has a 4 year warranty.

 

[Hootbro]

I understand their thinking on lowest bidder on parts, but the warranty headaches they've had with these low grade batteries has to have ended up costing them more than they made on the deal.

I think it is a bad design more than the batteries themselves being subpar. When you put batteries with large mismatched capacities in a parallel circuit, it basically makes them average each other out when it comes to charging and neither batter gets the best charge/discharge conditioning.

 

[kevman65]

I have the ESS (ASS) turned off with a Tazer, so that may be why I haven't had a failure or anything lighting up.
But yes, the whole dual battery set up from factory seems to not function as they thought it would.

 

[MrT]

I did the aux battery delete just over a year ago and installed a Odyssey battery. Yesterday we went to eat and when we got back in the Jeep I hit the start button and everything went black except the overhead interior light was flashing or flickering. I had a jump box which started the Jeep but it only ran for a minute until it drained the box.
There were no warning signs or dash lights so I assumed a fuse on the array popped. Luckily (I guess) the dealership was pretty close and I grabbed 2 fuse arrays, went back and installed one. The Jeep came alive but wouldn't start. We connected it to a friend's truck with jumper cables and after 30 minutes or so of fooling with it we gave up. I bought a temporary battery from Walmart and everything seems fine after driving around 30-45 minutes home the dash showed 14.2 I didn't check it not running though. It was an expensive day. Today I get to see if I can get the Odyssey warrantied.
I tested the array and now I don't think it was the problem. I have never seen a battery just die all at once so as of now cause is unknown.

 

[whysoserious]

My work commute is just around a 10 minute drive. I haven't had the opportunity to take a nice long drive in probably a month+, so my battery has consistently been at 14.8V.

I took an 8 hour drive yesterday and at approximately hour 5 my battery's voltage finally fell below 13V.

I had my phone plugged in and the heat on @ 30% which may have contributed to longer charging times.

5 hours @ 70-90mph still seems like a long time to me, anyone know the rate at which an alternator charges a battery?

Is it safe to assume you were reading the voltage "gauge" in the dash cluster while you were driving?

 

[ecidiego]

Odyssey requires a minimum charge voltage of 14.6 or something I believe. That's the problem....the IBS draws down the charge voltage from the alt.

I'll look this up again to be sure.

 

[ecidiego]

The best way to charge an ODYSSEY® battery is to use an AGM specific charger. Chargers such as the ODYSSEY® Battery Portable Charger have the required 14.7 volts needed to properly charge your ODYSSEY battery"

Jeep's system creates a problem for these nicer batteries. Granted it's talking about chargers but same applies for alt. They don't want the decreasing voltage.

 

[MrT]

Is it safe to assume you were reading the voltage "gauge" in the dash cluster while you were driving?

I usually have off-road pages up but I don't remember specifically noting the voltage. I am sure I would have noticed it off or any warning lights but it's possible I missed it. Everything was functioning properly until after eating.

 

[ecidiego]

More...

https://www.tundras.com/threads/cus...ging-profile-for-odyssey-agm-batteries.58290/

 

[MrT]

The best way to charge an ODYSSEY® battery is to use an AGM specific charger. Chargers such as the ODYSSEY® Battery Portable Charger have the required 14.7 volts needed to properly charge your ODYSSEY battery"

Jeep's system creates a problem for these nicer batteries. Granted it's talking about chargers but same applies for alt. They don't want the decreasing voltage.

I have run the same battery over a year in this Jeep and had the same setup in another Gladiator for around 12k miles. This is the first problem I have had.
I put the battery on a agm charger when I got home and it showed dead(25%) the weird thing is about 30 minutes later it showed 100% I disconnected it and reconnected it, back to 25% I am taking it to get load tested and hopefully warrantied. He factory battery is a similar size AGM battery.

 

[MrT]

More...

https://www.tundras.com/threads/cus...ging-profile-for-odyssey-agm-batteries.58290/

Thanks for that, I remember reading that when I made the switch. I kept a close eye on it for awhile. Also to clarify this batter was in both Jeeps so it has been run like this for about a year and eight months. It may have finally caught up with me I suppose.

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