Worlds cheapest battery maintainer...

http://www.harborfreight.com/automatic-battery-float-charger-42292.html

Was $9.99. HF had them on sale for $3.99, with the 20% off coupon it was about $3.00 .

Works well, 500ma constant output.

Only downside I see is that it is constant output... so for those folks who are energy conservationalists, that may be a down side...

I guess you could plug it in every several weeks...

 

well, it has to turn "off" to avoid boiling the battery dry....

 

Actually at 500ma its well below a trickle rate of C/10. Most car batteries are 700CCA, but have a capacity of 40-50A run time. So, in theory, the amperage is so low it doesn't risk that...

 

As opposed to 'trickle' chargers which have a more/less constant current, 'float' chargers use a constant voltage to keep the battery topped off. Electrons gradually cease flowing as the battery gets closer to full - as long as they are coming in at the right voltage for that temperature.

The manual seems to indicate a constant 13.2 volt output which is consistent with a float charger for all 'starter' type lead acid batteries. No mention of temperature compensation.

Note the many warnings against using it on Optima batteries. Must be a good reason but going over the Optima charge requirements, I can't find one.

 

Optima batteries require significantly higher currents to re-charge than conventional batteries. I suspect that 500mA wouldn't begin to help an Optima, so all you're doing is running the poor little tender flat out constantly, which I expect would eventually heat it up and kill it.

Check Optima's web site for their recommended charging setup. It includes connecting your Optima to a known good battery AND connecting a good charger to the pair of batteries. My assumption is that the second battery cushions the load on the charger so you're not overheating it either.

I am singularly unimpressed with Optimas. I have red tops in my daily driver work truck and in my Diablo. Bought them for their good reputation and resistance to vibration. In both applications I have found them to have pathetically low reserve time and if they go flat, only my 200-amp starting charger is able to keep up with their current demands until they come back up to voltage. That same charger has a 40-amp setting which will be overdrawn recharging a flat Optima. Considering they cost double what a good quality conventional battery does, I'd rather replace a regular battery twice as often.

 

The Ferrari dealer installed a Battery Tender Plus set up for my 308. The charger lasted about 10 years...just to the point where the warranty expires. Since I couldn't find the original receipt to send it back for repair, I just purchased a new one. They run about $50-60 on various websites. I didn't want to wait for shipping, so I found one at local auto parts store...with tax about $62.

 

Old saying, but true in many instances, such as this -- You get what you pay for. You want cheap, buy cheap. You don't have to overpay for something, but at least buy something designed to do the job correctly. I have a couple of Craftsman automatic battery tenders that do a great job. I think I paid between $25 and $30 for each of them, maybe a bit more. I also have a full-fledged battery charger that also tests the battery. The right tool for the right job, as they say.

Wasting even a few bucks on something that isn't going to work is silly. Especially when the real deal is not that much more expensive. If you can afford to have a Ferrari in your garage, you can afford even as much as $50 for a decent battery tender to keep your baby topped up over the winter or when otherwise not in use.

My $.02.

 

I have heard similar bad stories about Optimas and honestly I would not have bought one had I heard these first.

But I may have gotten a good one. Yellow Top. I put it in my 308 back in 06 and never had a problem so far. I have a Schumacher charger mounted in front of it and the power cord peeks out of the front grill. Whenever I need the car I just plug it up a day or two before and it is always ready when I am. A few times I let it die totally by accident but just a day or two on the charger and it's all good again.

It has been 5 years now, Perhaps I need to start thinking about a new one, even if it is a different brand. How much longer can this thing last?

 

I've never said anything negative about Optimas, only that the HF Charger manual states several times not to use it on them.

I have heard Optima battery life is shortened if they are installed in an overly hot environment. Unfortunately, the 308 battery are subjected to the full brunt of hot radiator air, a much harsher environment than conventional under-hood temperatures. Just as 308 alternators next to the exhaust manifold benefit from a hot air deflection plate, the same technique could work for the battery and get a full 7 years from them.

.

 

Not so much you but other's here have had some bad experiences and have been very vocal about it. Bothered me a little since I have one but, like I posted, so far so good.

 

Harbor Freight also offers a floating maintainer. I think not on sale about 10 bucks.

I've used them for years with no problem. Cars can sit for 8-12 months(even longer) and I've never had a dead battery when I've finally tried to start.

 

13.2 volts are enough to trickle charge a lead-acid battery of the type having liquid acid, which has an open contact voltage of 12.7v at end of charge. Gel batteries have a slightly higher voltage, about 13.2v, so they won't accept much current from this charger.

Stefano

 

Well then... hear it now!

There is a 360 Spider running around these parts that had a 2.5V battery maintainer hooked up to an Optima battery that "Baked" overnight. The 360 has the battery in the passangers footbox inside the car and many seem to buy into the "sealed battery" thing as a justification to use them in this application. It has been 4 years now and still the leather interior stinks to high heck like battery acid..... the leather soaked up all the fumes from that battery going bad.

I have seen so many failures of these batteries I suggest replacement at first sight. The super high CCA might be good for some hydraulic lowrider or something with a speaker the size of a kitchen table but aside from that there is zero benefit to having it.

Cheap battery maintainers are simply too much risk for a Ferrari sitting in an attached garage, just as Steve said. When I remove them from a Ferrari I put them on my trailer winch battery, tractor battery, Ranch Rat Land Cruiser.... anything but something that will be parked in the garage.

 

These optima battery rules are no different from a wet cell. In fact the current AGM battery is technically a wetcell. It is the "gel" battery that is mildly different.

http://www.optimabatteries.com/product_support/charging.php

I have used optima's for years no issues and as they die I cycle them to my trailer winch. I took the HFT battery charger to another level and been using it this way since 2009. That HFT POS is a float charger so it senses full charge after an absorption phase then cuts back to maintain just like any float charger. The technology for this is very low tech. My super awesome Deltran tender lasted about a year before it died. So much for a sophistocated tender.

http://ferrarichat.com/forum/showthread.php?t=249955

 

no ferrari here, but i had one of the $5.00 HarborFreight chargers kill a battery in my ducati.

so now i have a Battery Tender Plus and three plugs wired to the batteries of my bikes, and i just rotate the Battery Tender to each bike every other month or so [odyssey's in the ducati and a Vmax, and a gel BikeMaster in a GSXR 1100] the Battery Tender Plus "seems" to be a quality charger, i am hoping so anyways [all three batteries new this spring, and i would prefer not to buy any more for a couple years anyway]


as far as the optima thing goes, i have a blue top in my boat, so far so good, the rack storage place ran it down once but it came back, and i just replaced a 9 year old orange top in my landcruiser with a new 34R redtop[they dont make the reverse terminal 34 series in orange anymore], so i have had good luck with them but like everything else they probably have good ones and bad ones too.......


doug

 

In my opinion the Optima is overrated and overpriced!

I've always used Interstates as replacements and have had them last for years. They're 1/2 to 1/3 the price of Optimas and last just as long; if not longer.

 

Were you using a battery charger or a floating maintainer and, how do you know it was the charger that killed the battery?

 

We had one of the very first red tops installed in my to tow rig years ago...This was maybe 2000 or 2001? It was fantastic...couldn't kill it. Dropped it, no problem. Fell off the battery tray into the radiator fan, no problem. Best reserve capacity of any battery I had.

The same went for the 6V 'half size' batteries. They were great for transplanting into the various older cars we'd move around.

Fast forward to today, and they just don't seem to have the same longevity, and the price is higher. Just had a brand new 6V die off in the Cobra (we run 2 6v in series).

Interstate makes a good battery, personally I like Deka batteries. They have black cases and when you remove the decals, its not so obvious they're a replacement battery.

 

Does anyone have experience with the battery "maintainers"? Light aircraft guys are using these now. Rather than just float charge, they have some type of microprocessor controlled conditioning cycle that prolongs battery life.

Similar to this

http://www.batteryminders.com/batterycharger/catalog/BatteryMINDer-2012-AGM-12-Volt-2-Amp-12V-2A-Charger-Maintaine-p-16179.html

 

This is the thing that scares me. I have been lucky for 5 years but that cannot continue forever.

What Battery do you recommend? I trust your opinion (and your products being a happy customer). 308 QV

 

it was the HarborFreight floating maintainer, and i guess u could be right, i dont "know" for sure but the battery had been good, but i wasnt riding the duc much, and when i went to check on it and start it the charger had failed [no led] and the battery was dead, i tried a regular 2/6/10 amp smart charger but it wouldnt come back, i also read somewhere you can "force" a battery to come back with a high amp charger such as a shop might have but i had no such charger available, so i just revamped my garage system [new batteries for all my bikes[the vmax and a used gsxr came in that needed one anyways] and a better quality charger]

i took that HarborFreight charger apart, later i messed with it again and the led came on but i am leary of it so it sits in a drawer[unused and unloved at the moment]

by the way, i have found the Battery Tender junior charger for around 30.00 at amazon, and the leads that attach permanently to the battery are about 9.00, seems like a good charger so far, this winter will show if it will maintain the three bikes for me

doug

 

thats what i seem to be reading a lot lately, and my "orange" top was my first optima[2002 maybe] and lasted forever, even in my FZJ80, which i dont drive much except in the winter, now i am watching my newer blue top in my boat like a hawk/and will have to monitor the new "red top" 34R i just put in the cruiser.

doug

 

Optima red top installed in the 512TR in 2004, maintained with Battery Tender when not in constant use.
37,000 miles on that battery and still going strong.
I'm a believer.

 

Mileage on a car is meaningless compared to battery life; age is!

Your battery is 7 years old, it's at the end of its life. A battery is merely a reservoir to store electrical power to start your car and maintain accessories. If your charging system is operating properly, you can actually disconnect the battery and the engine and components will work fine.

Again, mileage is meaningless!

 

I has a HF charger connected to my Porsche that was recently painted. Had it sitting on the roof of the car under a pad to keep from scratching new paint. 2 weeks later went to
remove the charger to do some more reassembly. It had shorted out and melted. thankfully the pad under the charger blocked the melt down from damaging the new paint.

Never again...I have CTEKs for all of my cars.

David