HeadsU.P.

There really is no need to run a Battery Tender 24 / 7. I went to Walmart and purchased a 24 HR timer that plugs into a wall outlet. The tender plugs into that timer. There is a dial on the timer with 48 half-hour settings. You can have the tender / timer come on a couple hours in the morning, couple hrs in the evening, whatever turns your crank. I watch for the green light on the tender to let me know battery is fully charged. Only 1.5 hrs of maintaining a day is plenty enough for my set-up. That $7 timer saves a lot of wear & tear on the tender.

HeadsU.P.

Basically you are deep-cycling. Instead of maintaining a full charge (almost) constantly with a tender, you allow your battery to discharge 1% per day. And that's with no cables attached. Add a clock, stereo setting memory, alarm, etc hooked-up and you increase the parasitic draw. So after 30 days you have lost 30%. Then you run the engine and charge it again to 100%..
(That's deep cycling)

REELAV8R

I've seen several comments about the schumacher maintainer, personally I have 8 of them and none of them have ever had a problem or "fried" a battery. If the power is interrupted, as it is on occasion where I live, they reset automatically. So in my experience they are good. It may depend I guess on what model of schumacher maintainer you have.

Haggisbash

Not only lightning can cause issues with spikes, switching transients on the high voltage network can cause spikes also. There could have been one of these when your supply went off or more likely when it came back on.
Your supply is low voltage but a spike on the HV side of the network can propagate itself on the LV also, the HV/LV transformer in-between won't stop it. How far away your location is from the supply transformer and the sub station can make a difference.
We are talking about very high voltages here (in the spike) but they only last for a few milliseconds in most cases, long enough to damage electronic circuits though.

Bikespace

Get a battery quick disconnect (it'll pay for itself the first time you have to work on the car anyway). If you drive every month, no problem! Otherwise, disconnect the battery over the winter. If it really bothers you, pull it out, and charge it on the bench (or in the car) with a proper battery charger or power supply.

I have a whole-house surge protector, but I'm still not going to plug a car into the wall.

drwet

I've been using the Battery Tender Jrs for many years. I have them on pretty much everything I own that doesn't get driven, ridden, started, or run on a daily basis. I probably have about a dozen of them. I had one fail about a year ago. Nothing serious, just quit working. They have probably doubled the life of my batteries.

69_Shark

I have a battery tender with 4 outputs mounted to the ceiling in my garage.
2 vettes a Harley and a Lambretta scooter all get plugged in when not used for more than a week.

Works great! No issues.
I can peek into the garage and look at the status lights and see what vehicles are plugged in and fully charged!

I really like the set up!
Scott

windyC6

I've been saying and doing this for years. No need at all to tender a batt full time. I leave mine hooked up, but probably only juice it maybe 4-6 hours 2-3 times a week. They are making everything so darn cheap these days I wouldn't like leaving anything like one of these cheap chargers on 24 - 7.

Tiger Joe

i actually like the idea of putting the battery tender on a timer. honestly I never thought of it but it makes sense to not have it run 24/7/365.

I use battery tender brand and schumacher brand. I've never had a battery tender brand break- have singles, a 2 bank, and a 4 bank, some are 15 years old. I had 1 schumacher break after like 4 years, but I think it was dropped.

i can say without a doubt that these tenders have paid for themselves in saving batteries. I use them not only on my cars, but on riding mowers and some of the heavy equipment we own- which sometimes sits for months at a time. I have a battery in one of my classic trucks that is 12 years old. have got almost 7 years out of lawnmower batteries- which used to be 2 or 3.

Anthony F

HeadsU.P.

My Deltran Tender like others goes into a monitor mode or standby mode, float mode, what ever you want to call it, when it senses the battery is fully charged. But no matter how you look at it, the trickle charger is still plugged in, still running, still "ON" even when not charging. That's why I went to Walleys for a 24 HR timer ($7)

You would be surprised how little running time it takes each day to get the green standby light on. I started at 8 hrs / day. Then 6, then 4. Now the timer is down to about an hour & a half per day. (providing I don't open the drivers door)

OldCarBum

I've used Battery Tenders for over 40 years on boats, motorcycles and cars.
Never had any issues and I've always plugged them into a surge protector.
Before my clock quit ticking the tender would switch from standby to charging about once every couple of weeks for a few minutes then switch back to standby.
Since my clock quit, I haven't seen the tender go from standby to charging in over a year.
I also start the car and let it run or drive it at lease once a month.

Neil B

I am not a fan of my Battery Tender. But my inexpensive Autocraft has served me well. I also just bought a 12/24v Duracell charger which is surprisingly high quality.

HeadsU.P.

"Your Clock" quit ticking or the cars clock quit ticking? I guess if its your clock, we should call 911 right? Anybody know the phone number for 911?

OldCarBum

911 in California, 119 back east.

HeadsU.P.

How do you know which "1" to dial first? The first "1" or the second "1".

OldCarBum

It's always the middle one first!!!

Sunstroked