Needed to shoehorn my Optima RedTop into friend's Jag X-Type this morning and to get cables connected, laid it on its side. I know you can do this, being gel, but for how long?

A friend at work has used one this way in a street rod for over a year now.

Is this a riddle?
My understanding is that they will operate in any orientation. Low riders like to fill the trunk with them sideways to operate their hydraulics.

Optima says any orientation except upside down is fine.

they're not gel cell battries. basically they are just 6 large capacitors wired together. I think almost identical to the stiffening caps used in high end automotive sound systems. they can store large amounts of current, then release it when needed. A friend used one as an extra battery to run his system, mounted it sideways inside the car covered by custom access panels. so they don't have to have a lot of venting either.

When I picked up my Optima the sales guy bragged they could mount anyway but upside down. Also mentioned you could crack the housing and the battery would still be usable. Or as he put it "Shoot it and it will still work".

Uh, no. Optimas are lead-acid batteries, just using a different design from most other lead-acid batteries. They're completely sealed, with no vent at all. You can run them on their side or upside down.

They're most certainly NOT capacitors.

Almost right. They are built like a capacitor, but they are still a lead acid battery. "Valve Regulated Lead Acid" and "Absorbed Glass Mat" are names for the technology. It doesn't have to be wound in a spiral, Hawker does the same thing with square batteries. The lead plates are thinner, and sandwiched between them are sheets of fiberglass mat soaked in sufluric acid. This gives them the high current capability of capacitors, but the desiarable discharge curve of a lead acid battery. (a 100% charged 12v capacitor is 12v, a 50% charged 12v capacitor is 6v... a 100% charged 12v lead acid battery is 13.8v, a 50% charged 12v lead acid battery is around 11.5-12v depending on battery chemistry. Most battery companies will have specs relating to their open circuit voltages at various charge levels, if anyone cares that much.

I pumped 17.5 volts into one for a few hours......they certainly are vented. They vent green stuff. Got a new one for free, tho.

The vents are little rubber caps underneath the white disks on the top. They are sealed up until a certain pressure, then they vent so they don't explode. When they vent, they make a chirping noise. They should never vent under normal use, so if it does you're either overcharging or have a defective or worn out battery. (They don't like being overcharged or run down too far) I killed one by letting it go down to 4 volts. It charged up again ok, but it would self discharge in about a week, and lost much of its capacity. Eventually it stopped taking a charge. Hopefully Tony never finds it.

I have the same optima in my 75 914.. We use similar Gel Cels in our Formula Vee race cars and they are mounted on their side on the floor of the car under our legs... never heard of any problems resting a gel cel sideways.

rob

Nope, not Gels, AGMs.

Most people don't know the difference, and they are quite similar, the most important difference to me is that you can get more power out of a AGM. Lots more! But I suspect that a Gel wouldn't mind being upside down at all.

The factory is wrong. Yes, I've been using them longer than probably everyone at the factory, since the early days when John Olsen was head chemist. That guy knew what was up. It's not as good to run them on the side, life will be shorter. Shorter than the 10+ years one can get in starting use. So it's not that big a deal.

They will work for years on the side, but during charging they can leak a little bit of acid, especially if the vents are on the lower side and you charge them over 14.2 or so. So if you are mounting them on the side, put the vents up and the terminals lower. It only takes a little acid loss to hurt them.

Yes they work when cracked, but if you don't weld them back up the life becomes shorter.

I've given up on Optima. The quality control is not what it used to be.
For now I prefer the Exide Orbitals. They rock!

Otmar: Please tell us again why you think the Exide is the hot set-up.

I've had good luck so far with Optima's.. I've heard a few bad wraps about them but, so far it's all good for me.

I like to keep up on new battery tech-. Oh and my brother-inlaws, brother-inlaw owns a Exide distributorship here in the south bay.

Thanks, Pat

Hi Pat,
First off, you all should know that I tend to use these things 20 at a time, and since they are powering my 914 they see not only high currents but deep cycles as well.
Problems with the batteries show up pretty quickly in this kind of use.
Traditionally, we would expect a 10% to 20% fallout rate of Optimas. These were ones that would show up as dogs before 20 charge/discharge cycles. After that we could run them for about 300 deep cycles. (or many more shallow ones)
It's been maybe 5 years since I bought a set of Optimas, and I was getting decent performance out of them, but since then I've spoken with other users who test them quite thoroughly and they tell me that the Optima quality control has gone downhill. This is no surprise as they seem to have ousted the people who knew how to build them.

So knowing this, we all went looking for a better battery.

The Exide batteries are made under license from Optima, so they have the same spiral wound construction. Exide made them 10% lighter (40 lbs instead of 44 lbs) and so they do have a bit less reserve capacity (range for me) but they also changed the intercell interconnects so they are shorter.

The disadvantage to this change is that the terminals are out near the edge of the batteries and can sometimes interfere in mounting, but the advantage is more power. I've melted the long internal interconnect strap in the Optimas by pulling over 1500 amps. No one has yet managed to blow a Orbital and they have been run at over 2000 amps. At all currents, we find the Orbitals hold a higher voltage while dishing out the amps. In my car, changing from Optimas to Orbitals saved 80 lbs and dropped my 1/4 mile time from 14.4 to 13.8 seconds.

Next, you may know that the Optima has two vents. When you charge the battery, it will gas a little bit internally and so long as you don't charge it too much this will get re-absorbed into the cells. The vents are there to let off steam if you overdo it and they are active when first forming in the plates of a new battery.
On the Optima the top of the inside of the battery is all one chamber. So if your battery happens to be mounted at an angle, gasses that came out of the upper cells will condense and drip back into the lower cells. I think this is why on my last set of Optimas, all my first failures were in the front batteries which I had at an angle while the rears which were level were still going strong.

The Exide Orbitals have 6 vents, one for each cell and the cell dividers are sealed to the top. This means that if one cell gasses because it came up to charge first, it will also get that moisture back when it cools down. This is a great theoretical advantage. I don't have enough experience to prove that it works, but it could help account for the long pack life that I've heard Sparrow owners have gotten with Orbitals. Some Sparrows have had Exide Orbitals for years so they are the best test data we have so far.

Lastly, the Orbitals are quite a bit cheaper. And who doesn't like that?

Disclaimer: Exide sponsored me on my batteries.
OTOH the guy who sponsored me is no longer there. This means that if I didn't think they were great, I would probably just be quiet about them. Fortunately I don't have to censor what I write since I do like them.