It is very cold, how do I know if the car battery is good and the car will start?? What is the best car battery test method?

[Whitenuckler]

I see what the problem is/was with the small 1.8A charger I am using. The one I had in there before let the voltage go down to 12.27V, and I'm not sure if it would have come on in. I must have left it in maintain mode, as if it were in charge mode, it would not have shut off. I have the "bad" one hooked up to another battery in the garage and will keep an eye on it.

The "new" one I put in yesterday was left on "maintain mode" so I could get a curve of how it works.
The voltage got down to 12.34V (55% Charge) and then switched on.
I am not going to use that mode anymore, as an AGM voltage profile is higher, so it is letting it get too drained if set up for a flooded.
In one hour the voltage dropped from 12.43 to 12.38 so 0.05V per hour. That is with the battery charger still connected and the BM200.
I will need to hook a meter up to the battery neg and measure the milliamp parasitic draw.
I conclusion, I recommend these BM200. I am impressed with the quality of the data, and the crank/charge test. Very good app. Good trend screens.
I am able to hold it near my kitchen window about 30 ft from the truck and update the data.
My battery seems good, the problem was that it was not getting charged properly and I didn't know.

Followup - Again I can't say enough good things about the BM200. I have been watching the voltage verses time with another 1.8A charger of the same type, one I thought was "good". I have seen the Jeep battery discharging even when I left the charger on (not maintain). Then I went and lifted the hood and the charger had switch to off. A closer look at the data showed it spent about 2 hours at 14.5V, then about 2 hours at 13.5V, then shut off and did not turn back on. When I was shopping for more chargers I did see some said they had a built in timer. I will have to read the small instruction paper that came with it and check. I have a work-around for it. I hooked it up to a wifi plug under my hood and set a timer. 2 hours on, 1hour off ect. That way it's gets restarted. I have 2 new battery charger coming, two different types, so I will be testing them out when I get them.

https://www.amazon.ca/ANCEL-BM200-Bluetooth-Automotive-Lead-Acid/dp/B0BZ8D71NY/ref=sr_1_1_sspa1

 

[begreen]

I have a simpler version on the EV6 12v battery. They put cheap FLA batteries in the earlier years and switched to AGM a few months after our car was made, so I watch over it. I track it with this.

https://www.amazon.com/dp/B01MT4583U?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_2&th=1

 

[Whitenuckler]

I have a simpler version on the EV6 12v battery. They put cheap FLA batteries in the earlier years and switched to AGM a few months after our car was made, so I watch over it. I track it with this.

https://www.amazon.com/dp/B01MT4583U?ref_=ppx_hzsearch_conn_dt_b_fed_asin_title_2&th=1

Oh Ya looks like the same thing basically. Really nice to be able to see what's going on in real time and in the past. Would be great on an RV or simple solar system too. Boats too. Some guys troll with a separate battery. And then some boats have a house battery and machinery battery.

 

[Whitenuckler]

Here is my charging profile after the wifi switch was added. 2 hours on, one hour off. The next step will be trying the new chargers.

 

[zrock]

Ancel BM200 Bluetooth Battery Monitor

Just installed this today. I am having issues with my Jeep.
I wanted a wifi one, but they are harder to find and more expensive.
I can't get the bluetooth in the house very well, but can in the porch.
The app seems good. It is able to record the crank cycle ie voltage verses time.
Also has a charging test you can run with the car running.
I have a trickle charger on it now so I can make sure it's charging remotely.

If this is being left plugged in all the time it will be part of the reason your battery is low. Years ago i had a LED version on a ATV so i could see at a glance what condition the battery was in. If the unit sat for a week the battery was dead even after replacing it, once i took the LED off the battery never went dead again. Now 1 little LED should not be able to draw down a battery in a week, so how much is your little gadget pulling if its trying to keep Blutooth and any other feature it has alive.. Will not be the whole culprit but it will be part.

Even short drives the veh should be able to keep the battery charged as the alt will ramp up the charge voltage. My truck drives 5 min one way to work every day and that is about the extent of its live and my battery has never went dead even in -30.

 

[Whitenuckler]

If this is being left plugged in all the time it will be part of the reason your battery is low. Years ago i had a LED version on a ATV so i could see at a glance what condition the battery was in. If the unit sat for a week the battery was dead even after replacing it, once i took the LED off the battery never went dead again. Now 1 little LED should not be able to draw down a battery in a week, so how much is your little gadget pulling if its trying to keep Blutooth and any other feature it has alive.. Will not be the whole culprit but it will be part.

Even short drives the veh should be able to keep the battery charged as the alt will ramp up the charge voltage. My truck drives 5 min one way to work every day and that is about the extent of its live and my battery has never went dead even in -30.

Yes, I agree. My battery charger, and now the BM200 draw a few milli amps. I had nothing connected at all in the beginning, and was getting hard starts. The battery is new. I blame the root cause as parasitic draw. These Jeeps are loaded full of electronics. To really check it I need to get at the battery negative terminal/cable under the passenger seat. I will check it when the weather warms up.
I agree also if you start out with a 100% charged battery, even a short trip charging at the huge DC amps will soon recharge it.
For now I'm all set. It will be fully charged and the short time I spend out will not discharge it too much. I don't know how I would spend all my free time without all these problems to solve.