12v battery needs replacing?

[gboudreau]

4 years-old LEAF 2011.
Went to the dealer today (changing tires, yearly battery test), and they tested my 12v battery, and told me it should be changed soon.
The Diagnostic Charge report they gave me says:

Rated: 55B24
Measured: ---- CCA
Voltage: 14.46V
Elapsed: 00:05:02
Amp Hours: 0.0
State of health: 50%
REPLACE BATTERY

From reading other threads, I thought 14.4V was what it was supposed to be at, when fully charged, so why does that report say I should change the battery..?

They also told me I should soon change my brake pads, which are at 52-54% (front-back). That I'm pretty sure I should not do until I reach 25%, or start hearing noises...

 

[LeftieBiker]

The 12 volt battery - just like the main pack - can lose capacity and still have the correct voltage. They did a load test on it, which gives an idea of the present capacity, reported at 50%. The brakes are more a grey area; I wouldn't wait for those noises, but given the slow wear rate you may be able to go one more year on the current pads.

 

[Firetruck41]

When your brake pads need replaced, most modern car brake pads give a constant squeal from contact with the squeal tabs (even when brakes are not applied). Percentage does not matter, what matters is mm of pad thickness, there is a spec in the service manual that says when they need to be replaced. As little as the brake pads get used on these cars, I can't think of a reason to replace them "early".

 

[knightmb]

4 years-old LEAF 2011.
Went to the dealer today (changing tires, yearly battery test), and they tested my 12v battery, and told me it should be changed soon.
The Diagnostic Charge report they gave me says:

Rated: 55B24
Measured: ---- CCA
Voltage: 14.46V
Elapsed: 00:05:02
Amp Hours: 0.0
State of health: 50%
REPLACE BATTERY

From reading other threads, I thought 14.4V was what it was supposed to be at, when fully charged, so why does that report say I should change the battery..?

They also told me I should soon change my brake pads, which are at 52-54% (front-back). That I'm pretty sure I should not do until I reach 25%, or start hearing noises...

A poor battery can be charged to 14.4 volts but as soon as the charge is released and a load applied, it voltage drops quickly. You can do a simple test to see how much capacity does it really have. Turn your Leaf on standby (but not drive mode) which is usually two presses of the power button with the key in the car (but no brake pedal pressed). This will turn on everything except power steering and run it directly off the 12 volt battery. Next, turn on all the seat heaters for high, then turn on the fan and put it on high. This will cause a good power drain on the 12 volt battery. Time how long it takes before the car kicks in the main battery to charge the 12 volt back up. You'll know this has taken place when you see a single blue flashing light come on top where the charge lights are. The car kicks in the main battery pack once your 12 volt battery hits around 10.5 volts (from what I've measured doing the same experiment). A good 12 volt battery will probably give you about 15 minutes of power wasting before the big battery kicks in to take over. If your vehicle kicks in the main battery after only a few minutes, then it means your 12 volt battery is very close to capacity death.

 

[LeftieBiker]

When your brake pads need replaced, most modern car brake pads give a constant squeal from contact with the squeal tabs (even when brakes are not applied). Percentage does not matter, what matters is mm of pad thickness, there is a spec in the service manual that says when they need to be replaced. As little as the brake pads get used on these cars, I can't think of a reason to replace them "early".

Most of us would rather replace the pads a little early than have to get it done immediately once those brass wear alarm strips make contact. Also, pad wear can accelerate a bit, and become more uneven, as they near the end of their usefulness, so it can be hard to judge when they have no life left but there is no noise. With any other car I'd say to replace them at the earliest convenience, but since the Leaf relies less on the brakes to slow down, I wrote what I wrote.

 

[powersurge]

Voltage of 12v battery is kind of high at rest. This sounds like a voltage when the car is running. Get a harbor freight battery tester 20 bucks, and see if the voltage drops when you press the load button. Also, 50 percent brakes on a leaf with regen braking is fine. You could probably go another 5-10 k miles with that. They sound like they want some of that money you have saved from not needing any maintenance!!!

 

[jpadc]

Voltage of 12v battery is kind of high at rest. This sounds like a voltage when the car is running.

+1 (and the wipers were on).

Get a harbor freight battery tester 20 bucks, and see if the voltage drops when you press the load button.

or any auto parts store where they will test it for free....

They sound like they want some of that money you have saved from not needing any maintenance!!!

Four years and how many miles on the car to get to that 50% mark? Likely you can wait on that for a bit longer...

 

[gboudreau]

You can do a simple test to see how much capacity does it really have. Turn your Leaf on standby (but not drive mode) which is usually two presses of the power button with the key in the car (but no brake pedal pressed). This will turn on everything except power steering and run it directly off the 12 volt battery. Next, turn on all the seat heaters for high, then turn on the fan and put it on high. This will cause a good power drain on the 12 volt battery. Time how long it takes before the car kicks in the main battery to charge the 12 volt back up. You'll know this has taken place when you see a single blue flashing light come on top where the charge lights are. The car kicks in the main battery pack once your 12 volt battery hits around 10.5 volts (from what I've measured doing the same experiment). A good 12 volt battery will probably give you about 15 minutes of power wasting before the big battery kicks in to take over. If your vehicle kicks in the main battery after only a few minutes, then it means your 12 volt battery is very close to capacity death.

Will try that. I also got a digital multimeter; I'll hook it up while I do this test, to see how fast the 12v battery drains. And will also check how much I loose when I leave the car in the garage overnight.

Four years and how many miles on the car to get to that 50% mark? Likely you can wait on that for a bit longer...

16,000 miles. Pretty sure I can do another year, maybe even 1.5, and get them replaced when I change my tires in the spring of 2017.

Thanks everyone for the feedback and suggestions.

 

[JimSouCal]

You can do a simple test to see how much capacity does it really have. Turn your Leaf on standby (but not drive mode) which is usually two presses of the power button with the key in the car (but no brake pedal pressed). This will turn on everything except power steering and run it directly off the 12 volt battery. Next, turn on all the seat heaters for high, then turn on the fan and put it on high. This will cause a good power drain on the 12 volt battery. Time how long it takes before the car kicks in the main battery to charge the 12 volt back up. You'll know this has taken place when you see a single blue flashing light come on top where the charge lights are. The car kicks in the main battery pack once your 12 volt battery hits around 10.5 volts (from what I've measured doing the same experiment). A good 12 volt battery will probably give you about 15 minutes of power wasting before the big battery kicks in to take over. If your vehicle kicks in the main battery after only a few minutes, then it means your 12 volt battery is very close to capacity death.

Will try that. I also got a digital multimeter; I'll hook it up while I do this test, to see how fast the 12v battery drains. And will also check how much I loose when I leave the car in the garage overnight.

Four years and how many miles on the car to get to that 50% mark? Likely you can wait on that for a bit longer...

16,000 miles. Pretty sure I can do another year, maybe even 1.5, and get them replaced when I change my tires in the spring of 2017.

Thanks everyone for the feedback and suggestions.

The battery test idea is a simple clever method without a load tester handy. I am going to try it on my 2011. Thanks knightmb.

I'd agree on the brake pads... Also, you might drive very differently, with less hills, and get less wear. On mine, again, a 2011, with little hill driving without regen, I have very little wear.

 

[keydiver]

Pretty sure I can do another year, maybe even 1.5, and get them replaced when I change my tires in the spring of 2017.

You're a brave man. Try to have a backup plan, like a battery jump box or jumper cables. Most batteries that are right on the edge will die swiftly when the first cold front hits.

 

[Stanton]

Weird things happen when the 12v battery in the Leaf goes (or is going), including brake problems (unrelated to worn brakes). I wouldn't push your luck: get a new 12v battery.

 

[gboudreau]

Pretty sure I can do another year, maybe even 1.5, and get them replaced when I change my tires in the spring of 2017.

You're a brave man. Try to have a backup plan, like a battery jump box or jumper cables. Most batteries that are right on the edge will die swiftly when the first cold front hits.

I have both (jumper box at home, jumper cables in trunk), and am plugged in at work 2/5 days. But I was talking about the brakes, not the battery.
For the battery, I'll do some more testing, and try to see if I can get a voltage reading using the OBD-II port too, and decide once I know more.

 

[Randy]

I bought a new 12v battery at the 4 year mark for $89.99 and everything is working well....Why take a chance you'll get stranded somewhere when you least expect it?

http://www.mynissanleaf.com/viewtopic.php?f=9&t=19169

 

[dud]

OP,

Risk is defined as the probability of a negative event occurring. In this case you losing power to your accessories and/or losing braking ability. While you MAY be fine for a while longer ... why chance it?

A new 12v battery can be had relatively in expensively, cheaper at a local auto parts store with a coupon. Many will replace the battery for free. You should receive a nice, long replacement warranty.

If you are a DIYer ... consider doing the brakes yourself. The parts can be purchased at a discount. I've done a number of pad/shoe replacements for $20 to $40. I would agree with many here that your brakes probably have a bit of life left on them.

Good luck ...