i have a spare battery on one of those battery tender devices.

is that really good enough to keep it alive?

the problem is i just bought a 7 year battery from autozone. it will be a while until i need another one.

i guess i could swap them around once in a while but the thing is so darn heavy.

what are your opinions?

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Jennifer
90 350sdl

I'm not sure I would keep the tender on it 24x7. There are some good ones and some bad ones. I know of someone who has wasted two airplane batteries in the last two years. However, if it's not a cheapie, I would keep the battery OFF of concrete and NOT where it can freeze. Put the tender on and every month or so, check to see if the battery is warm. If it is, take it off the tender; it is overcharging.

The best way to store a lead-acid battery long-term is to remove the acid, but I don't recommend it.

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Michael LaFleur

'05 E320 CDI - 86,000 miles
'86 300SDL - 360,000 miles
'85 300SD - 150,000 miles (sold)
'89 190D - 120,000 miles (sold)
'85 300SD - 317,000 miles (sold)
'98 ML320 - 270,000 miles (sold)
'75 300D - 170,000 miles (sold)
'83 Harley Davidson FLTC (Broken again) :-(
'61 Plymouth Valiant - 60k mikes
2004 Papillon (Oliver)
2005 Tzitzu (Griffon)
2009 Welsh Corgi (Buba)

Sell it. Then buy another one when you need it.

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Rick Miley
2014 Tesla Model S
2018 Tesla Model 3
2017 Nissan LEAF
Former MB: 99 E300, 86 190E 2.3, 87 300E, 80 240D, 82 204D Euro
Chain Elongation References

Why keep it OFF Concrete ?

Russ

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1978 300 D 258,000 + miles sold 1995
1983 300 D Turbo 152,000 miles
Thank God for the man who put the white lines on the highway

From the tech section at BatteriesPlus:
What is the proper maintenance for a lawnmower, motorcycle, or marine battery during the off season?

The battery should be disconnected from the application and stored in a cool, dry place. It is extremely important to maintain voltage via a trickle charge (1-2 amps) for a maximum of 6 hours every 6 to 8 weeks.


Is it really true that it is bad for an automotive or motorcycle battery to be stored directly on concrete?

This is a myth. It did have some basis in fact with the very early designs of these types of batteries when the outside case material was somewhat porous and allowed minute amounts of electrolyte to seep through the case to the concrete. This would in turn react with conductive materials in concrete and cause a voltage drain thereby "killing" the battery. Today, all batteries of this type, have a polypropylene exterior case which is extremely resistant to any leaks unless damaged. Storage of a battery directly on concrete will not harm the battery.

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Rick Miley
2014 Tesla Model S
2018 Tesla Model 3
2017 Nissan LEAF
Former MB: 99 E300, 86 190E 2.3, 87 300E, 80 240D, 82 204D Euro
Chain Elongation References

I think the other gentleman was refering to the conductive nature of concrete and how it would work like a big heat sink when compared to being placed upon wood.

No, I was interested what myths and stories would be recanted about storing batteries on concrete floors. I already knew that the concern about storing them on concrete floors is an old myth that doesnt apply to modern batteries.

Russ

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1978 300 D 258,000 + miles sold 1995
1983 300 D Turbo 152,000 miles
Thank God for the man who put the white lines on the highway

Sell the battery! Incidentally some of the new battery maintainance devices have microprocessors that monitor voltage and only charge when needed ceasing the charge cycle when the battery is topped off. They are supposed to be okay to use indefinitely. RT

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When all else fails, vote from the rooftops!
84' Mercedes Benz 300D Anthracite/black, 171K
03' Volkswagen Jetta TDI blue/black, 93K
93' Chevrolet C2500HD ExCab 6.5TD, Two-tone blue, 252K

i would still keep it off the concrete. put it on a piece of plywood.

If it happened to leak it will ruin the concrete.

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1985 300D Turbo ~225k
2000 F350 (Powerstroke) 4X4, SWB, CC, SRW, 6spd ~148k
1999 International 4900, DT466e (250hp/660 ft/lbs), Allison MD3060 ~73k

we always kept ours on wood..

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1984 300D Turbo - 231k....totalled 11/30/07 RIP

Saw a great little charger at Menards awhile ago and bought one. It has new high frequency technology that speeds up the charging time with no overcharge. Seems to have a nice set of features, including a de-sulfating cycle and three-stage charge . I notice that JC Whitney has them too but Menards price was way better. I'd guess that this charger would monitor the battery and take care of it just right. Best upgrade in charger tech. in a long time.

You should be pretty safe with a decent quality battery tender. I have a couple of old cars with 7+/- year old batteries that are left on tenders almost constantly. You do need to keep an eye on the electrolyte levels though. If the tender is working right there should be almost zero loss of fluid but over 1-2 years time the level will go down slightly.

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LRG
1987 300D Turbo 175K
2006 Toyota Prius, efficent but no soul
1985 300 TDT(130K miles of trouble free motoring)now sold

I knew of the myth but thought it better to advise so "just in case". I thought I would get more people respondint to keep it off contrete than that it was ok to do so.

I myself never paid attention to what I had the battery sitting on.

I thought that would stir a few up. Wanna talk about green anti-freeze now?

__________________
Michael LaFleur

'05 E320 CDI - 86,000 miles
'86 300SDL - 360,000 miles
'85 300SD - 150,000 miles (sold)
'89 190D - 120,000 miles (sold)
'85 300SD - 317,000 miles (sold)
'98 ML320 - 270,000 miles (sold)
'75 300D - 170,000 miles (sold)
'83 Harley Davidson FLTC (Broken again) :-(
'61 Plymouth Valiant - 60k mikes
2004 Papillon (Oliver)
2005 Tzitzu (Griffon)
2009 Welsh Corgi (Buba)