Charging Optimas (AGMs)?

What's the Voodoo, black magic, procedure for charging these things?

I've got a Yellow Top I left hooked up in a Jeep for ~13 months without ever cranking it, which eventually drained down to 3.something Volts.

My 12 year old "smart" charger from Schumacher wouldn't do diddly to it, I'd hook it up, it'd analyze, start charging, and tell me it was full in 5-10 minutes.

Google told me I needed a charger that would do AGM batteries.  I considered buying a C-Tek, Genius, or Optima charger, but while at HF a while back I noticed their Viking chargers.  Last weekend the Viking 2/8/15 Amp Automatic Charger was on sale, it says it does AGM so I bought it.

My initial attempt at charging slow at 2 amps for ~18 hours didn't accomplish much, and never got past 40% capacity according to the readout on the charger.

After the charging didn't seem to be working, I tried the "Repair Mode," but it automatically shuts off after 24 hours.

I've gone through 3 24 hour repair cycles and 3 long charge cycles one was 24 hours, 2 at 2 amps and 1 at 8 amps. I've made headway, but I can't get the battery to show more than 60% capacity according to the charger's readout. I got voltage up to 11.something at one point, it actually cranked the Jeep, but right now it's at ~10.7 volts.

I'm currently running another repair cycle.  The cycles for sure desulfate the battery, you can smell it after running it for a few hours.  The battery gets pretty warm during the repair cycle as well.  Yesterday morning it was cool enough you could see that the battery was venting out of the safety valve thing on  top.  Is that a bad thing?

The battery is new enough it should have some proration left on its warranty, should I just replace it?  Should I go through a few more repair cycles?  Should I take the Viking back to HF and get one of the higher end chargers?

I have ruined several of these expensive batteries by letting them drain down too far. Sadly, only once was I able to save it. I don't know the science and I'm sure someone will explain it but you can't let the gel batteries get discharged. I think something inside them corrodes, rendering them fubar.

Yellowtops are deep cycle batteries, IIRC. There's a good chance it'll come back.

I use C-Tek Multi 7002 chargers. It's one of the few that Odyssey recommends for theirs and it's been able to take very good care of all my AGMs.

Hook a second, good battery in parallel with your dead Optima, then hook your charger up and start a trickle charge as normal.

After about 5 minutes, remove the good battery and let the charger work on the Optima.

We used Optimas at work for a long time and that's what the battery dealer told us to do and it worked for most of them. Most "smart" chargers are too smart to charge a totally dead battery.

If it doesn't work, throw the Optima away and buy an Odyssey. They're fantastic, I have a 12 year old one in my Moto Guzzi and it keeps chugging along.

We've also had very good luck with a brand called "Northstar" Apparently they're 100% new lead, not recycled stuff and they seem to last a good long time.

Optimas are junk, we've had more trouble with them than anything else.

After a couple bad experiences with Optimas I sprung for the Optima brand charger when I bought a bluetop for my sailboat. So far so good....

In reply to Keith Tanner :

Yep, Yellow Top is deep cycle.

In reply to Trans_Maro:

The Optima paper work recommended hooking up another good battery if you don't have an AGM charger, I tried that a few times with no luck before I bought the Viking charger.

Pop the top.....yes pop the top (screwdriver/ice pick) .......fill cells with distilled water keep an eye  on water level while charging......charge complete reseal

759NRNG said:

Pop the top.....yes pop the top (screwdriver/ice pick) .......fill cells with distilled water keep an eye  on water level while charging......charge complete reseal

You'd probably want to use distilled & deionized water.

Is that applicable to AGM batteries as well?

Optima definitely went through a rough patch a few years ago. We were selling them at the time and had massive failure rates. An Optima rep then publicly mocked me on this forum for it, so I have a hard time recommending them to anyone. We use Odyssey on anything new. I have two Optimas remaining, one is my jumper pack and the other lives in the camper where the solar keeps it topped up.

I'll definitely help someone keep an ailing Optima going, because at the very least it means that's one more battery that Optima won't sell.

The "attach to a good battery" trick isn't just for AGMs, it's a good trick to get the charge started on a very, very dead battery. Once you've got some voltage in there, though, it shouldn't be necessary.

AGMs usually can't recover from being totally flat, but maybe the Yellow top is immune being a deep cycle.

I hit the easy button.

I pulled the battery and took it back to Advanced (where I bought it), guy that greeted me was super helpful, tested the battery, 10V, failed their tester.  I didn't have to say much, guy got my info, started typing on his computer, and exchanged a new battery straight up. 

I'm typically an O'Reilly's and/or NAPA man, I usually only use Advanced for their online coupons, and pick up in store.  I went ahead and got oil and filter for the Grand Marquis while I was at Advanced, having originally planned to go on to Walmart since it's so much cheaper there.  I told the Advanced guy, he was the reason I was buying the oil and filter there, because he was so helpful.  He responded, something like, "Man seeing someone walking in my store carrying an Optima, something is wrong, that isn't something I expect, and I'm going to do what I can to take care of it."  Say what you will about Optima, I guess their marketing works, at least on dumb Jeep owners, and Advanced Auto Parts Employees.

This experience will likely have me patronizing Advanced more frequently.

I think the Viking charger is going back to Harbor Freight, that 24 hour shut off is a stupid feature.  So I'm in the market for a "legit" Optima/AGM capable charger, and I believe at least one or maybe both of the Jeeps are going to get a solar charger/maintainer.

loosecannon said:

I have ruined several of these expensive batteries by letting them drain down too far. Sadly, only once was I able to save it. I don't know the science and I'm sure someone will explain it but you can't let the gel batteries get discharged. I think something inside them corrodes, rendering them fubar.

IME once a gel-cell battery gets a single deep discharge, it's garbage.

You *need* a smart charger to charge an AGM.  A dumb charger can let the voltage get too high.  As little as 15.5 volts will let the smoke out of a redtop Optima.  (Now there was a fun learning experience)

AGMs have some advantages but they are temperamental beasts, and I'd rather deal with using a battery box.

Trans_Maro said:

Hook a second, good battery in parallel with your dead Optima, then hook your charger up and start a trickle charge as normal.

After about 5 minutes, remove the good battery and let the charger work on the Optima.

We used Optimas at work for a long time and that's what the battery dealer told us to do and it worked for most of them. Most "smart" chargers are too smart to charge a totally dead battery.

THIS.  Actually this is true for all batteries.  If you have a totally-dead battery, connect a good battery in parallel before you connect the battery charger.

makes me miss my old Sears "dumb" charger that I inherited from my Father when he moved to Florida. It was great until it got crushed in the shed.

I've been using the C-Tek chargers at work and at home with great results. On FLA and AGM batteries.

Every customer gets one included with his car when the car is delivered.

As the owner of a red top that’s been resurrected, I’ll second the idea of the “second, good battery inline with the start charger.” 

It worked. Optima even has a video for this. 

mad_machine said:

makes me miss my old Sears "dumb" charger that I inherited from my Father when he moved to Florida. It was great until it got crushed in the shed.

"Dumb" chargers are exactly how you let the smoke out of an Optima.  They will overvolt the battery, and when I use the term "let the smoke out", I mean it in a very literal jetting-from-the-vents sense.

In reply to Knurled. :

Is it sad that I want to see this happen?

In reply to Trackmouse :

Not really, it was kind of cool.  It was a redtop that had been discharged one too many times and was replaced, so I was trying to resurrect it to keep for myself.   If it worked, I got an Optima of dubious future lifespan, and if it didn't work, I got a learning experience. 

I had the battery paralleled and on a low current charge for most of the day.  In the mid afternoon I checked it and determined that it was up enough to not need to be paralleled anymore.  At 5pm I noticed the jetting smoke and the battery was hot to the touch...