[sokoloff]

I'm looking at a 2014 Smart EV and I asked to see the battery test. What I was given is the first attachment. What I have had done for mine is the second photo. Is the first one sufficient to tell me that the battery is okay? I see no Ah number.

Len
2014 EV

 

[SuperSmartie]

The first attachment tells you nothing about the state of health of the battery. The second one has at least the capacity. Even better would be the one that lists all cell voltages, but good luck trying to teach the MB techs how to do that.

 

[Blaine]

If you have the time, and MB will permit you to connect it to the OBD port, I'd say build a copy of @odyssey s battery tester

 

[jzchen]

I would be worried if the car has a lot of miles on it, but just based on the mileage. I've had the '12 Prius v in the household sit for a very long time. It currently has about 15k miles. MPGs are still good from what I can tell. What kills batteries seems to be use/cycling. About 49K on the '13 C-MAX Energi, of which 30k is EV mode, what used to be about 21 miles range best is now down to about 18 at best.

From the test of the car in consideration I see 97% current battery charge, and -0.41 A current, meaning I believe it is currently charging, and not done yet. I would be concerned if it was 0.0 A, and the battery was at 97% charge. The variation between voltage of all the cells added together is 0.1 V less than the net voltage of the battery, I'm assuming "net" is measured at the anode (-) and cathode (+). I would be concerned if there was a significant discrepancy. Looks good to me from what I can see, unless it has a lot of miles on it. Yes, it doesn't note the capacity, but I'd go by the mileage.

Try to get a snap shot of the projected range on the display. Could be a helpful indicator....

 

[jzchen]

I mean it looks like it's currently charging. (Sorry if I'm mistaken!)

 

[SuperSmartie]

The car is not charging. Current measurement polarity is from the point of view of the battery i.e. positive current is adding to the battery charge. -0.4A is normal for a car that is turned on (feeding the DC-DC converter to power computers, etc.). This has nothing to do with battery health.

 

[MB DNA]

Try to get a snap shot of the projected range on the display. Could be a helpful indicator....

"Projected range" is just a number from the guess-to-meter that can be impacted +/- by many variables to include historic.

Unfortunately Len is at the mercy of the smart Center and what they are willing to do for FREE in order to secure a sale?

Agree with SuperSmartie, he has not truly gotten the battery "health" report which unfortunately many sales people can't communicate such a request to the service folks who don't want to do it for FREE?

 

[jzchen]

The car is not charging. Current measurement polarity is from the point of view of the battery i.e. positive current is adding to the battery charge. -0.4A is normal for a car that is turned on (feeding the DC-DC converter to power computers, etc.). This has nothing to do with battery health.

Thanks!

Strange they have a negative number for current and a positive for voltage....

 

[jzchen]

"Projected range" is just a number from the guess-to-meter that can be impacted +/- by many variables to include historic.

Unfortunately Len is at the mercy of the smart Center and what they are willing to do for FREE in order to secure a sale?

Agree with SuperSmartie, he has not truly gotten the battery "health" report which unfortunately many sales people can't communicate such a request to the service folks who don't want to do it for FREE?

Well. If it displayed 85 miles projected range it would be more likely that the battery is okay, as opposed to 65, was my thinking....

Just trying to make use of the information at hand.... ?

 

[SuperSmartie]

Well. If it displayed 85 miles projected range it would be more likely that the battery is okay, as opposed to 65, was my thinking....

No, it would be more likely that it's a nice day and the last owner drove like a granny.
As MB said, the range guessometer is sensitive to lots of things like driving style, weather, and if the fan is turned on. Battery health is - if at all - at the bottom of the list and dwarfed by the other parameters.

 

[stevenvillatoro]

Well. If it displayed 85 miles projected range it would be more likely that the battery is okay, as opposed to 65, was my thinking....

Even a perfectly healthy HV battery pack, when driven without prioritizing conservation, would likely update the ED's projections very quickly to reflect a driving range of 60-65 miles when at 100% SOC. After I reset my stats, my gauge will indicate about 91-92 miles of range, but then successively update itself to reflect real-world conditions. After just a few discharge/recharge cycles, it goes back down into the more realistic (for my driving style) low-60 estimated mile range.

 

[jzchen]

So if I drive like I needed to get to the next charger like my life depended on it, very slow and gentle, my wife's car with decreased range will not say 21 miles ever, but used to. Maximum nowadays is around 18. So the higher it shows the better chances it is still in good shape.

I'm not trying to say I know the battery condition based on what has been given. I am just trying to help clarify what may be more likely with what is given....

Thank you all for explaining/clarifying

A lot of times I read about how a battery should be fully charged, have a cell balancer, etc. But when it comes down to the bottom line, as you use the battery it will slowly degrade, or at some point, in particular with hot weather, may more rapidly degrade with use. There are detailed instructions on how to care for in stock vehicles which sit on the lot for a long time on startekinfo.com. I have come accross them at times, in particular for the gas version. I'm afraid I do not think the staff at a dealership cares to follow them, which may lead to draining/damage of the starter/accessory (12 V) battery. But for the drive battery with it's different chemistry, I do not think this same concern applies. Or would you say a high mileage example would be a better candidate than a low mileage one for purchase?