New Optima Battery DOA (almost); And Getting Worse

BTW. Here's a good graph that illustrates the difference between charging voltage and rest voltage for a typical lead-acid battery.

Thanks guys for your answers. I guess the bottom line is I want to make sure that my battery is not defective, and based on what some people were saying earlier, I thought my battery at 12.5 volts was about 50% discharged.

Because I'm still learning about this stuff I thought the battery should be reading higher than it actually was. I also was wondering if the MFD was reading lower than what uart said it should in post #53 (.2 volts lower than measuring directly from the battery). The graph OptimaJim included also is helpful for me in gaining perspective.

The battery charged all of last night, and went into float mode after about an hour, so it was in float mode for about 15 hours. I am going to check it out in a few minutes, and will be interested to see if the voltage is any higher. It's also going to be warmer today with temperature in the 50's, so maybe that will make a difference as well.

Sounds like I'm worrying too much. Before I didn't even concern myself with the battery...I expected it to work and it did!

Chuck

OK, I just took it off charge. Interestingly, it was not in float mode like it was last night when I went to bed. Battery measured the same voltage as the other time, 12.5 volts with no load according to MFD, temp in the 50's outside. With a load of lights only, it was measuring about 12.0 volts. With additional load of the fan and brake, voltage was dipping to about 11.5 volts. Charging voltage was the same at 13.9 volts.

Are these readings in the ballpark of what I should expect?

Sounds like it's near a full charge. Charging voltage on my MFD is usually 14.x and usually closer to 15 than 14. If the computer thinks your battery is fully charged the charging voltage will drop.

Hi Chuck,

As others have mentioned, the most-accurate voltage reading will come directly from the battery. I can't speak for what the load of different accessories will do to the voltage reading of a battery, but if there is a voltage drop in the MFD reading, it sounds like your battery is in the ballpark of where it should be.


Jim McIlvaine
eCare Manager, OPTIMA Batteries, Inc.
www.facebook.com/optimabatteries

as a followup I happen to be replacing the battery in my Prius so I pulled out a DC meter, the charger, and started a test run.

The new battery out of the box read 12.52 volts measured at the terminals (not connected to a car).

During Phase 2 the voltage read 14.x volts (it varied but was usually around 14.5). Note this is charging voltage not the battery voltage.

Phase 2 only lasted about 6 hours.

The light on the charger changed to Green (Fully Charged) but the charger is still in Phase 3 as it just tested at 13.x volts. This could be charging volts or battery volts. Since the tester doesn't say if its in mode 3 or 4 I don't actually know if it's still charging. Mode 4 doesn't charge all the time, it charges then doesn't back and forth as the battery goes above / below 12.9V due to charging vs self discharge.

Since the phase 3 behavior is to drop amps and keep the voltage constant I won't have an easy way to check for the progress or end of that phase. My meter might read amps but I'm used to using it for volts and besides I don't plan on checking it in the middle of the night.

I'm just going to leave it on the charger overnight (an additional 12 hours for a total of 18 hours). I don't know if the battery will be fully charged before then or if it will even be fully charged after 18 hours. Worst case scenario I figure it'll have 80% charge but I'm expecting more like 95% to 100%.

I can check the voltage after taking it off the charger, let it rest for a bit while I'm taking the battery out of the prius, and then check it again during installation, and finally check the MFD to see how that compares to the hand checking with a meter.

I'll post more when I have the data. Then we can get optima to tell us how my test data compares to theirs in terms of charge levels.

OK, voltage recap

out of box 12.52
after 18 hours on charger 12.94
after connection to car but car off 12.72 (SKS load)
MFD check 12.5 on screen, didn't check at battery* (ACC)
MFD check 12.25 on screen, 12.45 at battery** (IG-ON)
after turning car off again 12.59 at battery (SKS load)

MFD check with IG-ON + headlights on 11.9

*MFD checked again with "accessory mode" instead of "IG-ON" but the fan was at low speed, didn't seem to be enough draw to make it worth turning the car off and on again since the MFD only shows voltage to one decimal place.

**MFD check was with door activated lights off, AC off, radio turned down to 0 vol, as low a load as I could give the system in IG-ON and still get the MFD to give me a signal check.

I'll let you know if I have any problems with the battery but I'm assuming this is normal readings for now.

I'm going to put the old Toyota battery on the charger to see what the apples to apples voltages are but I'll tell you now it was at 10.5 Volts when I took it out.

If the list above confuses you we could format it this way

HTML:

At Battery   vs  MFD
12.52            N.A.   out of box charge level

12.94            N.A.   after 18 hours on charger
12.72            ??.?   connected to car (SKS load)
??.??            12.5   accessory mode (SKS + display and such)
12.45            12.25  IG-ON (SKS plus a ton of other systems)

12.59            N.A.   car off after first round of testing

??.??            11.9   IG-ON plus headlights on

It would be interesting to do the MFD check again with IG-ON, headlights ON, and/or rear defogger on, so we know the voltage of the battery under some load.

Thanks for the info dhanson865. Are you sure that the Prius was in "Accessory" mode and not "Ig on" mode when you measured 12.25 volts. That seems like a lot of voltage drop for very little load. (Note that Ig-On powers all the Prius's systems and adds at least 10 amps extra current draw compared with Acc).

I had to turn it on far enough to have access to the AC controls and such. I suppose that is "ig-on" not "accessory".

I just wanted to make sure I wasn't measuring headlights, dome lights, heater, or AC compressor.

I did a lot of driving today, more so than I normally do so I could go back and check the MFD values again now it should have a full charge with the long trip I took + the 18 hours on the charger.

I paid more attention to ACC vs IG-ON when I went back for current numbers and updated post above with some current numbers after driving the car all day, since the IG-ON number matched before the trip I put them in the same list, I don't think the battery charge changed enough to separate the data.

Yeah it makes a LOT of difference whether it's in Ig-On or not, perhaps as much as leaving on the headlights. That's the problem with a lot of the reported 12V battery measurements, they're not very meaningful unless you know the load under which they're measured.

What I do if I'm going to take a 12V measurement is to turn off everything (fans lights radio etc) before I shut down the car. Then after it's been sitting for several hours or so I go take the measurement.

I like to do one measurement in just "Acc mode" (which should be about as close to the no load voltage as you can measure on the MFD) and then do a second measurement in "Ig-On" which should be 10+ amps load. An alternative test with the headlights on.

Without knowing how much power various Prius accessories draw or even what other owners see in terms of voltage drops with various accessories on, it is hard to comment on anything other than the voltage after being charged for 18 hours, which at 12.94 volts looks normal.


Jim McIlvaine
eCare Manager, OPTIMA Batteries, Inc.
Optima Batteries - Automobiles and Parts - Milwaukee, WI | Facebook

Just to be clear I was assuming it was normal and was giving the other readings as a baseline comparison for other Prius owners.

i believe the optima can only be charged at 1 amp with the correct maintainer--- check it out

We do not recommend exceeding 10 amps when charging our batteries with a charger, although in a maintenance (float) charging mode, amperage is typically significantly lower and we do recommend a maximum of rate of 1 amp in that mode. You can see more information on charging and maintaining our batteries in this video.

Jim McIlvaine
eCare Manager, OPTIMA Batteries, Inc.
OPTIMA® Batteries (OptimaBatteries) on Twitter

I also just received a bad one. Optima DS46B24R Yellow Top from BatteryMart. Dead on arrival, charged it overnight. My drive to work is 45 mins each way on the second day I needed a jump to get the car started as it would not boot the computer. Charged again, this is when I found this thread, and needed another jump that day. I have now put the OEM battery back in. The only reason for replacing was age it's the original in a 2006. We'll see if BatteryMart is as good as eLearnaid on the warrantee. I do have previous experience with Optima though, I put opima's in both of my 1957 MGA's. They are really great batteries, one of my cars has not been driven for more than a year but I can go out and it will start no problem.

pascoprius, when you charged the battery, what kind of charger did you use and what settings did you use? If the battery can hold voltage when fully-charged and disconnected from your car for 12-24 hours, it should be ok. If does not maintain close to it's fully-charged voltage when disconnected from your vehicle, you may need warranty service.

Jim McIlvaine
eCare Manager, OPTIMA Batteries, Inc.
OPTIMA® Batteries (OptimaBatteries) on Twitter

Sent it back to BatterMart, Hopefully they will send me a new one. with the OEM battery back in I have had no problems for the last week. When I charged it it was with a 10 amp charger on the gel/agm setting. As I said in the original post, I have Optima's in my MGA's this one did not perform the way those do. It's really embarrassing to have to ask for a jump for your Hybrid/electric car.

Please keep us posted on the service you receive from your retailer. We've done quite a bit of research on chargers on the market and have found that the "gel/agm" setting on chargers will typically not fully-charge non-gel batteries, due to the narrow charging parameters common amongst gel batteries. For that reason, we do not recommend charging our batteries on any setting that references "gel."

We also recently filmed a tech tips video with the folks from Powermaster alternators, as both companies commonly deal with customers who fall into a cycle of dead batteries and jump-starts, until either the battery or alternator fails. We both recommend fully-charging deeply-discharged batteries as soon as possible, whenever they are deeply-discharged to the point that a jump-start is needed, so I'm glad to see you weren't relying solely on the Prius charging system to recover your battery.

Jim McIlvaine
eCare Manager, OPTIMA Batteries, Inc.
OPTIMA® Batteries (optimabatteries) on Pinterest

Just heard back from BatteryMart, they are replacing the battery under warrantee. I thought Optima batteries were "gel/agm" batteries. Obviously that is not correct. Can you explain further?