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Charging system issue

15K views 17 replies 7 participants last post by  ajchien  
#1 ·
My wife mentioned the CR-V was cranking slow and I load tested the battery and it seemed to do alright. I bought a Topdon BT600 battery tester and the first reading I took said the battery was 5% charged at 12.03V and was measuring 408 CCA, the cranking was low at 1616ms and it dropped to9.04V. Charging system said normal at 14.3V. I put a battery charger on the battery and it said replace when it was fully charged so I went and bought a new battery and put in. Now I'm getting a charging system low reading and I can't understand why when the only thing I did was put a charger on it. Nothing arced or sparked and nothing got anywhere near the alternator. Any idea why it would go from14.3 to around 13v with the vehicle running? The alternator or battery light is not on.
 
Discussion starter · #8 ·
I believe with a new battery, the system wouldn't be in a 'charge' mode since the battery is fully charged or very close to it. Once it has drained some and goes below the threshold that triggers the 'charge' mode, it'll read differently. It should read 'charge' mode with the headlights on.
Honda has some weird charging protocols all in an effort to improve mileage.
What does your car read when running with the head lights 'ON'?
With the headlights off it is running 12.8 to 12.93, with the headlights on it is running 14.34 to 14.38. I repeated this test multiple times and got the same results, headlights on says charging is normal while headlights off says charging is low. I don't know what to make of it or if it needs to have something done to it. Do I need to tell the wife to always run the headlights so it will charge or will it charge on its own once the battery needs to be charged?
 
Discussion starter · #9 ·
Honda and many manufacturers are now using what is known as "smart charging". In their efforts to improve gas mileage, the alternator can be commanded to charge the battery at 14+ volts or maintain battery at 13+volts. The Electrical Load Detector (ELD) senses the electrical load. Signal is sent the ECU. ECU, then, determines whether to put alternator in high charge or low maintain voltage.
Do the 2014 CR-V's have this? If this is normal I'm good but I don't want my wife or daughter to be stranded out of town if it isn't
 
Discussion starter · #10 ·
You could test this out by turning on the lights with the car off. Leave them on for a while, then start it up to see what happens. Personally I wouldn't stress a system like that, but if you're skeptical that is one way to do it.
What size battery did you put in your CRV when you replaced the original one?
I went with the Group 24F option about 5 yrs ago or so and haven't had any problems since. I do check the battery cell fluid levels @every six months though as they do go down, even in a maintenance free battery.
I removed a 51R and replaced it with the same, battery I bought was made last month and when I tested it before putting it in it was 100% health and 100% charge
 
Discussion starter · #12 ·
You're good to go on the battery and the charging system. Your '14 is saving you gas by not asking the alternator to charge until it's necessary.
Thank you, I was worried I would have to take it in or start shopping for an alternator, never seen one do that before. So it is functioning properly and the wife doesn't have to run the lights all the time, it will come on as needed to keep it charged? Life was easier before I got the tools to read things like this to give me things to worry about lol