Charging-related error message, battery specs and replacement

[jludave]

I get a check engine light and a beep on turning the ignition to “on”, before starting the engine

This is normal.

Are you saying you do this before starting the engine every time? If so, you do not have to do so. All you need to do is step on the brake and push the button.

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[Pilotjeep]

This is normal.

Are you saying you do this before starting the engine every time? If so, you do not have to do so. All you need to do is step on the brake and push the button.

I don't normally do this, no. Normally, I hit the brake and the button like everyone else. In this case, I was just switching to ON before starting so that I could read the system voltage beofre the engine starts.

 

[Pilotjeep]

Your new voltage readings look pretty good. The 14.5+ V while driving with the old battery was a result of the Jeep struggling to charge a bad battery.

I believe your system is still resetting itself after losing power during the battery change; the climate and screen theme should return to normal soon. I'm not sure about the CEL, but I think it is normal to see one with the Jeep set to ON - hopefully someone else can clarify.

Re voltage, I had thought about that and wondered if that might be the case. So good to hear someone else suggest it. Do you know a number or range for the normal running voltage?
I wonder whether my mileage may improve now, if the starter generator isn't constantly overworking, trying to charge a battery that won't take a charge.

Re resetting, the climate control has already started acting normally, and the check engine error may be gone on startup - I will check on next start. It definitely is not showing the check engine light while running any more.

 

[THAW]

Re voltage, I had thought about that and wondered if that might be the case. So good to hear someone else suggest it. Do you know a number or range for the normal running voltage?
I wonder whether my mileage may improve now, if the starter generator isn't constantly overworking, trying to charge a battery that won't take a charge.

Re resetting, the climate control has already started acting normally, and the check engine error may be gone on startup - I will check on next start. It definitely is not showing the check engine light while running any more.

My OE AGM battery has "LIMIT CHARGE VOLTAGE TO 14.4 VOLTS MAX" printed on it, for what that's worth. I have a 240A alternator, but I usually see 14.3V or lower on my dash while driving. I believe readings over 14.5V may be indicative of an issue, especially if long duration.

As for fuel economy, in theory it should improve but in practice it might not be noticeable. Let's hope it improves significantly!

 

[Pilotjeep]

My OE AGM battery has "LIMIT CHARGE VOLTAGE TO 14.4 VOLTS MAX" printed on it, for what that's worth. I have a 240A alternator, but I usually see 14.3V or lower on my dash while driving. I believe readings over 14.5V may be indicative of an issue, especially if long duration.

As for fuel economy, in theory it should improve but in practice it might not be noticeable. Let's hope it improves significantly!

Yes, my OE battery has the same charge voltage limit warning.

I've got no alternator, this is an eTorque with the belt starter/generator. So far it hasn't passed 14.3 V with the new battery.

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