The place I have been storing some of my cars just sent me a note that my low-power trickle charger overcharged and ruined the new battery in the Lotus Elise.
It was suggested to me that you should always put a trickle charger on a timer, so that it only charges a few hours a day.
I have never heard of that before. Have you? I thought modern, electronically controlled trickle chargers worked such that they could be “set and forget.”
Meanwhile, we’ve got some spring cleaning going on at the SCM bat cave. This was the first winter in which most of my cars didn’t have to hibernate there. For various reasons at least a few will probably be back there at the end of the driving season.
It’s an uninsulated garage with a ceiling-mounted heater and fan. There wasn’t much need to run the heat this past winter, but I’m expecting to have to turn it on come November.
What temperature do you think the heat should be set to? 50 degrees? And with the ceiling mounted heater rotating, do we need to also run an auxiliary fan just to keep the air moving?
I am hoping to get answers now to avoid problems in the future.
Thanks in advance for your responses.
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Keith,
This is EXACTLY what I thought and this is what I got when I did a google search:
“Yes, most modern trickle chargers for automotive batteries have automatic shut-off features. They are designed to prevent overcharging and damage to the battery. These chargers typically use a built-in current regulator and monitor the battery voltage to determine when to shut off.
Here’s a more detailed explanation:
Automatic Shut-off:
Modern trickle chargers are engineered to automatically stop charging once the battery is fully charged.
Overcharging Prevention:
This feature prevents the overcharging of the battery, which can lead to electrolyte loss, plate corrosion, and reduced battery lifespan.
Built-in Monitoring:
Trickle chargers often have built-in voltage and current monitoring systems that allow them to detect when the battery is fully charged and adjust the charging current accordingly.
Smart Chargers:
Many advanced chargers, also known as “smart” chargers, have modes for various types of batteries, including AGM, and may include features like desulfation to extend battery life.
Maintenance Mode:
Some trickle chargers have a “maintain” mode that keeps the battery topped up when it’s fully charged, preventing self-discharge.
In essence, modern trickle chargers are designed to be left unattended and will automatically switch off when the battery is fully charged and will only re-engage if the battery voltage drops below a certain threshold.
How do battery chargers tell when to stop charging? – Quora
Consumer Reports
“To prevent overcharging your battery and damaging it, trickle chargers feature a regulator that provides an auto-shut-off function that also allows them to kick back on once discharge is detected.:
Keith, I do not know much about electronics or electronics equipment, but to my very suspicious NYC mind, I think that YOUR STORAGE GARAGE MIGHT HAVE DAMAGED YOUR BATTERY by inadvertently CAUSING SOME KIND OF POWER SURGE ON THAT VOLAGE/CURRENT LINE THAT SERVES YOUR CAR.
On one of my old jobs, I had to go into parking garages in Manhattan and perform surveys and conduct inspections. YOU HAVE NO IDEA WHAT GOES ON IN GARAGES/CAR STORAGE FACILITIES when the car owners are not around. I actually saw two different garages, one on the Upper West Side of Manhattan and one on the Lower East Side of Manhattan, where each had hidden away from public view a full-painting/body repair work area. When the parking attendants made errors parking cares in these narrow parking multi-level parking garages and damaged the cars, they had body and paint men onsite to repair damages, dents, and scrapes – THEY WOULD DO THIS WITHOUT INFORMING THE OWNERS OF IT!!!!
So, PLEASE DO NOT ACCEPT AT FACE VALUE WHAT YOUR STORAGE GARAGE IS TELLING YOU! Their power surge might have destroyed your battery. I don’t know of any well-respected battery charger brands on the market that do not have an automatic shutoff, and I am sure with your beautiful car collection you did not cheap out for an inexpensive charger without one. PLEASE INVESTIGATE THIS FURTHER FOR YOUR OWN BENEFIT. Your garage might OWE YOU A NEW BATTERY!!!
Glenn in Brooklyn, NY.
I have 13 collector cars and almost are on trickle chargers and have been for more than 25 years. They have always performed as they should and my typical battery lasts 6 years. Nothing fancy, just the little green wall warts that I buy on Amazon, three to a pack!
It sounds like you are using the wrong device, or one that doesn’t work properly. Some people use “trickle charger” and “battery maintainer” synonymously, when in fact they are different things. You want an battery maintainer (CTEK is one example and there are others). I live in Canada where the temperatures can be as low as -40 F in the winter and above 94 F (periodically) in the summer. I use maintainers for at least 6 months in the “winter” and have used them all year – never removing them from the cars at all. I have been doing this for years on a whole range of cars (classics to new) with never an issue. I also store cars at ambient temperature (inside). If the cars are stored where no daily drivers come in an out in cold weather, then heating just above freezing should suffice (assuming this is on a thermostat and that the temperature throughout the garage is well enough circulated to be above freezing), but if there are daily drivers coming in and out of the garage then condensation on interior and exterior surfaces will occur which will ultimately affect corrosion rates (increasing them). We never heat garages with daily drivers.
Wow. Thats a new one on me! AGM battery? Makes me rethink my winter storage.
Keith – I always place my trickle chargers on a timer, as I never trust that they might overcharge. It seems and on time of four hours a day is sufficient to keep the battery charged . These timers are relative inexpensive and they’re on Amazon at $12 for two.
Best,
Ken
BN-LINK BND-60/U47 Indoor Mini 24-Hour Mechanical Outlet Timer, 3-Prong, 2-Pack
Hmm, thought the chargers timed out when fully charged? Never had a problem with any, but I guess there’s always a first time!
I have never had that problem with my CTEK trickle chargers on several cars over the last decade or so. We’re in Florida, and the building is well insulated. Do not use the AC or heat. No problems.
Keith, never use a Trickle Charger to maintain your battery (for obvious reasons). Always use a smart “Battery Maintainer”. It has built-in circuitry to keep the battery at top charge without overcharging. One brand that I like is “Battery Tender” available on Amazon or wherever fine maintainers are sold.
That only makes sense if it’s solely a “battery charger.” A battery maintenance device (Battery Tender, etc. – personally, I like Schumacher’s line of tenders) is designed to be left on 24/7, for all the above reasons by the other posters (especially if there’s changes in temperatures in the garage that affect the charging rate). If anything, I’d blame the battery, especially on a relatively modern car with an ECU like the Elise. Build quality for batteries has gone to crap (even the pricey “name brand” ones). I don’t trust a battery over seven years old, and I’ve had a several die inexplicably and immediately that were far newer. Then there’s the Out of Box Failure of my two most recent gel-cells…
Keith: I’ve had four cars on “smart” battery tenders for well over 12 years in the “set & forget” mode and have never had a problem. I see no need for a timer. Suggest that you might look elsewhere for the battery problem, if you have confidence in your tender.
To avoid “overcharging,” use a battery tender. However, the feedback circuit of the tender will not prevent a battery from losing too much electrolyte water during battery tending. From experience the battery tender light will depart from the green all-is-well to warn that something is amiss. So use a tender and check on it periodically.
I do not use a timer on my trickle chargers. No problems yet.
I once lost a motorcycle battery because my trickle charger boiled off all of the electrolyte over the course of a winter. Ever since my solution has been to charge all of my batteries (I have six of them) on the first of every month. I leave them connected until the trickle charger shows “float mode” and then disconnect until the next month. Works perfectly and easy to do in my garage.
Hi Keith,
First of all, thank you so very much for all of the wonderful things you have and continue to do to support us Petrol Heads. From the amazing auto value info that I know can’t be easy to continually gather, collate and present to all of the wonderful knowledge that you share, and allow us to contribute. My whole hearted gratitude to you and your team!
I’ve been using Battery Tenders about 50 years on usually several cars at a time and I’ve never experienced an overcharge. I stored a friend’s 90’s Ferrari and the factory charger did kill that battery (and it was his second one, and you know it had to be super expensive). After replacing it for him and using one of my Tenders, it’s been perfect for the last 2 years.
Batteries and tires. No matter what you do, they degrade. I have a bucket of trickle chargers, but they mostly sit in the bucket and some of my cars sit unused and quietly needing that trickle. Other batteries seem to have more fortitude, taking pride in sitting for 90 days+ and then cranking without complaint.
I don’t have much experience with heated storage, living in SC. And I don’t mean to hijack this discussion, but TIRES… If you own, say 6 vehicles, you’re buying a set of tires annually, if not more like every six months…
Something tells me the battery for the Elise is not its greatest expense this year.
I use a timer for my golf cart lithium battery trickle charger
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I’ve never had a problem using Battery Tenders, both for motorcycles and cars. Plug in, go away for six months, batteries are fine when I return.
I have always used timers on battery chargers for storage, charging for a few hours once a week. I’ve not changed this practice through 3-4 upgrades of chargers and better batteries. My thinking is letting the batteries rest between charges and what little energy was lost is ‘exercise’ when replaced. Two 4-wheel drives on chargers spend 9 months alone in an unheated Wyoming garage and one lasted 16 years before replacement.
Currently using BN-link BND60/US58S timers and NOCO 1 genius1 chargers.
Never heard of a need to put a trickle charger on a timer to prevent it from frying the car’s battery. I’ve been leaving one on various vintage cars for many months at a time. Qu: How did the guy who stores your car know the battery was fried? Do you have him maintain the car in storage with instructions to start it/them periodically?
The problem may be with the Elise’ electrical system, not the battery. After all, it is a British car….
The problem may be with the electrical system, not the battery. After all, it is a British car….