Optima Battery Problems

bajajim

New member
I am a retired electronics technician from Boeing and have some experience with these batteries.

The most comprehensive tests you can perform on an Optima are charging at 5 or more amps (this depends on the ah capacity of the battery) until the voltage reaches 15. If it doesn't reach 15 OR the temperature rises above 125° F then the battery is likely defective.

If it reaches 15 volts and you have a charger that you can switch to constant-current it should continue to charge for one hour at one amp or until the voltage no longer rises whichever comes first. If you don't have the ability to accomplish the above procedures then simply charge the battery until the voltage stops rising. REMEMBER to never allow the battery temperature to exceed 125° F.

The load test should be performed only after the battery has been fully charged. The preferred load should be about or above 50 amps and the battery voltage should not drop below 10 volts for at least 10 seconds. If you don't have a load tester and don't want to buy one you can simply put the battery in a vehicle and disable the ignition so it won't start. Have someone crank the engine and watch the battery voltage closely. If it drops to or below 9 volts the battery is defective.

I have two Optima D31M's in the bed of my Toyota truck and a 12 year old yellow top under the hood. They are all three in parallel most of the time but I can disconnect the rear from the front with a 100 amp circuit breaker so I can always start my engine.

Something I have noted about earlier Optima batteries and is still true to some extent is that while they can withstand vibration, the case is more vulnerable than a hard rubber case and if you drop one more than an inch or so it will probably crack. If the case cracks and you don't notice it and seal it, if possible, the battery will dry out and once that happens it is now a boat anchor or wheel-weight.
 

bajajim

New member
Sounds like your regulator chip is whacky! You are spot-on about the 14.7 volts being full charge in your application but once it reaches that level it is suppoed to keep up with demand and usually runs about 12.8 to 13.5 volts depending on load.

HenryJ: Thanks for the data! I've used those general specs before to determine battery condition. Unfortunately, unlike a wet-cell battery, you can't use a hydrometer on an AGM battery to accurately measure the SOC. It would be much easier if you could! Also, there are a few more variables in the equation, such as battery temperature and internal resistance (which tends to increase in older batteries). Internal resistance has an impact on both the charge rate and the discharge rate.

Based on those specs, with a charging voltage of ~14.7VDC and a presumed starting SOC of 20-25%, I'm probably seeing almost a full charge in a two hour period, but not a completely charged battery. The CTEK advertises it will put out up to 20A for charging, but the reality is that it will, like all smart chargers, provide the max amperage the battery will accept at the voltage level established. Optima states clearly that the maximum amperage to be used when charging their batteries with a constant voltage charger is 10A at a max of 15VDC. The limit for charging using an alternator is max 15VDC with no current limit. I have a 130A alternator, so current wasn't a problem before, but voltage was being regulated to a lower level, typically 13.1 to 13.4VDC after a few minutes of driving, that was much less than I needed to fully charge my aux battery. So -- if I'm able keep my charging voltage higher for a longer period, but always under 15VDC, then I should get a good charge and have no problems with over-charging.

There is a tendency to get too wrapped up in data, which can detract from common sense. I'm at that point now so it is time to quit and get out on the dirt. I can conclusively say that at this point that I'm getting what I need from my DC/DC charger -- which is a fully charged aux battery -- and that is good enough for me. Time will tell if this solution has any side-effects. Very few solutions are perfect :)
 

scrubber3

Not really here
So you posted so that you could be subscribed to the thread????? :rolleyes:
LOL man, when I post it never subscribes for me(at least not to my knowledge).... I just check in this section from time to time. Whenever I see this thread it makes me feel retarded for the sake that some of the stuff you guys have mentioned as far as charging confuses me to near madness... Makes me feel the need to go to more electrical classes. They didn't test me while taking my ASE in electronics on half of the charging techniques you guys use. Don't get me wrong, I know the reasons to do them the ways mentioned, but I am no engineer. I only had to fix what engineers jacked up whilst putting their degrees to use. :peepwall:
 

teotwaki

Excelsior!
LOL man, when I post it never subscribes for me(at least not to my knowledge).... I just check in this section from time to time. Whenever I see this thread it makes me feel retarded for the sake that some of the stuff you guys have mentioned as far as charging confuses me to near madness... Makes me feel the need to go to more electrical classes. They didn't test me while taking my ASE in electronics on half of the charging techniques you guys use. Don't get me wrong, I know the reasons to do them the ways mentioned, but I am no engineer. I only had to fix what engineers jacked up whilst putting their degrees to use. :peepwall:

I know exactly what you mean! I was a tech for a long time and know full well that a fancy degree provides just part of what is needed. A lot of this stuff is on the internet but I really like hearing actual experience with useful technical detail to help me better understand.

Anyhow, I'm sure that OJ hopes the thread is dead but that is not the case.
 

teotwaki

Excelsior!
That's a surprisingly hard question to answer. I don't have a science-quality test setup, so my data is what can charitably be called 'informal'. My subjective observation is that my aux battery has been charging back up in about 2 hours of driving from the approximately 11.5V I've used as a benchmark in my testing. This can get fuzzy because it takes at least 2-4 hours after shutting the engine off for the surface effect from the charge to dissipate and show the real SOC -- and I haven't always remembered to check it later. :rolleyes: The charge levels when I start the truck the next day (after some discharge due to parasitic loads) would seem to bear out my observations however. As I mentioned, I will be doing some long distance driving soon and that should help me understand the performance better.

The time to recharge is important to your application, so I'll try to get better data for you over the next few months. Interpreting the CTEK specs for a similar charger (XS 7000), it can take up to 8 hours to recharge a battery that is 'completely drained' (10.5V?) back up to 80% capacity -- in other words, up to 8 hours in the bulk charge phase. My battery is rated at 75AH capacity, which means I can get 75A out if I discharge it evenly over 20 hours. Thanks to Mr. Peukert, it can get a bit slippery to determine the total A/H I've been taking out of my battery during my test discharges as I'm certainly not taking 20 hours to to do it, nor am I taking the battery down to a fully discharged condition (doh!). Despite having faced up to my sloppy science, I can state with confidence that my aux battery is now charging much faster, and to a higher level, using the D250s as compared to using just my alternator and a relay controller. Which, after all, is just what you would expect :)

Hi Michael!

Any further opinions or updates based on your use of the DC-DC charger? My Optima definitely seems to be heading downhill despite driving the truck at lunch and running an AC powered charger on the battery when I get home.
 

Michael

Adventurer
Hi Michael!

Any further opinions or updates based on your use of the DC-DC charger? My Optima definitely seems to be heading downhill despite driving the truck at lunch and running an AC powered charger on the battery when I get home.

The DC-DC charger is working out very well for me. I've made several extended camping trips with it installed and I'm getting outstanding performance from my aux battery. My 2.5 year-old yellow top D-31T was showing symptoms of aging but now seems to be performing like it was young again :) It takes a better charge and holds the charge longer (i.e., over-night voltage drops are less). The CTEK D250s charger performs as advertised and it is doing exactly what I hoped it would do. For example, I camped in the Mojave Preserve several nights this week and after powering my CPAP and Engel 35 all night, my voltage readings in the morning were about 12.3V, much better than I've seen in the past for overnight use. I ran an extended "driveway" test a couple of weeks ago and left my Engel running for 2 days and 2 nights with a typical cooling load and the aux voltage dropped to 11.7V after 48 hrs of continuous use and warm temps. Again, much better than I observed in the past with the same battery before installing the DC-DC charger/isolator. Note: outside temps play a big part in power drain and I didn't attempt correlate temps with loads -- it was in fact darn cold at night in the Mojave this week!

That said, the way you describe your battery's performance indicates that a DC-DC charger may not be much help to you if you're already using an AC charger on your battery every night. The CTEK D-250s is just a typical smart charger and is probably similar to the AC powered charger you're using at home. The CTEK won't do anything more than what you're already doing if that is the case. Any charger needs a pre-determined length of time to fully charge a battery and there is no magic involved. My longer trips have allowed me to observe the indications of a full charge cycle from the D250s, and it was just as has already been described in this thread by dwh and others. The CTEK does maintain a higher charge voltage to your aux battery whenever you're driving, so there is certainly a benefit even on shorter trips. I have a DC meter that monitors both aux and starter battery voltages and I'm now used to seeing the alternator providing 13.1V to the starter battery at the same time the D250s is providing 14.8V to the aux battery. The real benefits are realized on longer drive times where the charger can run through a full charge cycle (again, similar to what you do at home). My daily driving around town has certainly been enough to maintain a full charge, but I don't discharge it every day like you do.

I would say that installing a DC-DC charger would do no harm to your current Optima and would likely improve its performance. I expect the real improvement would be with your next battery, where using the charger from the very beginning may reduce sulfation and better maintain the battery's SOC from the beginning. Good luck finding your optimal solution!
 
Last edited:

teotwaki

Excelsior!
Optima is dead.

dead cell after only 5 months

Optima-1.jpg

The dealer that I bought it through told me that the Optima distributor would fight against replacing it. He said they had a "huge" charger that dumped a "ton" of amps into batteries to bring them alive long enough to kick them back to the customer. He showed me half a dozen batteries that customers had brought back more than once.
 
Last edited:

mep1811

Gentleman Adventurer
I just had my Blue top Gp 31 battery replaced. It took a couple of trips to interstate and I left it for five days. They finally gave me a new one. I could hear them in the back load testing the battery and saying it still would not pass damn we have to give him a new one.

If I had to do it again I would buy the battery from Battery Plus they do not play those games.
 

Binksman

Observer
Autozone pulled that trick with me after I bought a new Redtop for the Jeep. I took it back three times until it exploded on their charger and caught fire :)

"Guess we'll replace that now..." The guy actually said that, with the fire extinguisher still in his hand.


dead cell after only 5 months

View attachment 98275

The dealer that I bought it through told me that the Optima distributor would fight against replacing it. He said they had a "huge" charger that dumped a "ton" of amps into batteries to bring them alive long enough to kick them back to the customer. He showed me half a dozen batteries that customers had brought back more than once.
 

Forum statistics

Threads
185,530
Messages
2,875,581
Members
224,922
Latest member
Randy Towles
Top