# Re: [EVDL] How to test a new Optima Yellow Top?



## EVDL List (Jul 27, 2007)

*Re: [EVDL] How to test a new Optima Yellow Top?*

Hello Tom,

When you buy batteries at a dealer and/or battery shop, have then test them 
with a battery analyzer, not a standard load tester which is use for 
cranking amps for a starter type of battery.

When they test the battery, monitor the screen and record the results, 
there will be several data points you can record. Label the battery and 
corresponding data in your battery records.

Have them provide you a copy of the battery specifications or you can get it 
from this battery web site, so you can compare the data.

Some small business that is not a battery shop, may not have this type of 
tester and some not knowing, will test these type of batteries with a 
standard load tester.

If the battery sheet data shows the Reserved Minutes @ Amps, then pick the 
column under the ampere you want to do the test. For example, A battery that 
has a Reserved Minutes @ 75 amps is 100 minutes, then if you applied 75 amps 
to a battery starting at 100% SOC, will be completely discharge to 0% SOC in 
100 minutes.

Instead of discharging to 0% SOC, you can proportion the time to the 
percentage of SOC. Make sure that the battery is at 100% SOC before you do 
this test as:



SOC% Minutes @ 75 amps

100 0
90 10
80 20
70 30
60 40
50 50

It is best not to go below 50% SOC with some type of batteries. The battery 
voltage for a 12 volt battery at 50% SOC should read about 12.10 volt. If 
you discharge it for 90 minutes to 10% SOC, it should read about 11.5 volts 
after you let it rest after the load is remove.

The battery analyzer performs this type of function by proportion the time 
down to a fraction of a second and gives you a readout in with seconds.

When I pick up my batteries from a battery shop, I have them perform this 
test. You will find that out of 100's of batteries that just came in fresh 
from the battery manufacturer, they could be up to 200 amps difference in 
capacity test.

I always specific, that I want a match set in voltage, load capacity state 
of charge, battery resistance and all the same manufacturer dates. Out of 
200 batteries they and I tested, I found only 26 that was all within 0.0001 
volt of each other and all the others that where either above or below that 
number. I will normally take the next highest ones over the base line.

In the sales contract, I always note that any battery that does not meet 
theses specification during the EV operations in with the warranty period, 
they shall be replace cost free. I only had to replace one battery out of 
thirty that did not come up to specs in with a month.

Roland






----- Original Message ----- 
From: "sanfranman12" <[email protected]>
To: <[email protected]>
Sent: Thursday, March 05, 2009 12:47 AM
Subject: [EVDL] How to test a new Optima Yellow Top?


>
> I just bought 6 new Optima D31Ts Yellow Top 12V. I have seen several 
> people
> warning me to test each of the batteries, because Optima has notoriously
> poor Quality Control. I do not yet have a running EV. What is the best 
> way
> to test a battery to determine whether I should take it back to a retailer
> for an exchange?
>
> Thanks.
>
> Tom
> -- 
> View this message in context: 
> http://www.nabble.com/How-to-test-a-new-Optima-Yellow-Top--tp22347427p22347427.html
> Sent from the Electric Vehicle Discussion List mailing list archive at 
> Nabble.com.
>
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