Any issue with Charging batteries in storage on timer?

[NYJoe]

Are there any issues that I should be concerned with charging batteries in storage on a daily timer? I have my trickle charger set on a timer for 3 hours daily. The two 12 volt batteries are connected in parallel and come to a full charge by the end of this charge period.
Last year I would fully charge the batteries once a week or so but had to remember to do this. I figure the timer would make this a no brainer.

Thanks

[Bill Gail]

If you are using a " Smart Trickle Charger" , I would leave it on full time . You should check the water level monthly until you determine how often you need to check it.

I use a "7 day timer" that I have set for 8hrs on every Saturday . This allows use of the onboard converter/charger which charges through a Magnum Battery Combiner so both the chassis and house batteries are being charged and maintained .

With my MH setup I found the batteries only needed water checked every 3 months during storage .

[jrollf]

Get a battery maintainer, not a trickle charger. A trickle charger never turns off and can destroy the battery. A battery maintainer will use a variable float charge to maintain proper charge.

With a proper battery maintainer you can leave it plugged in constantly, but you do need to check the water level every month or so.

[Persistent]

Names on packages often are defined by the mfg. marketing department. They are only concerned with boosting sales.

Double check function after you buy. Get a cheap digital volt meter at your local hardware store. Install the maintainer device. Periodically measure the terminal voltage until you know it is stabilized. Also monitor water level until you know how much will be consumed.

Stable terminal voltage must be above 12.7 volts for storing lead acid batteries. Lower than that will shorten life (decrease capacity).
13.2 volts is ideal. It will consume minimal water and not produce significant heat. Long life is assured.
13.6 volts is high for AGM sealed batteries. Don't go above this for AGM's.
14.4 is not ideal, but is OK for flooded cells. It will consume large amounts of water. It is very bad for AGM batteries. Some maintainers spike 14.4 volts periodically for conditioning flooded cell batteries.
15 volts is too high for storage. Don't do it.

Your built in converter/charger/inverter may do an excellent job of maintaining your battery banks. Do the same voltage measuring to evaluate it.

I wish you good luck and happy trails ahead!

[AnotherMike]

Agree with the above poster about trickle chargers not knowing when to quit and cooking batteries to death. It's happened to me.

Also agree about marketing departments and product names being picked to sell.

But I (and a number of electronic engineer friends I trust) have zero concern about the Deltran Corp. "Battery Tender" branded units.

I won't speak to the other brands as I have no personal experience.

A friend has two 3 amp "Battery Tender" brand 6v/12v units that he uses on his coach and chassis batteries while in storage. He pulls the positive cables off the batteries, clips the Tenders on and forgets them. Batteries stay fully charged and don't get cooked. With the positive cables disconnected there are no vampire loads to worry about. On the next rebuild of the battery system he's going to install a pair of BRSs (Big Red Switches) on the battery positive cables.

The Deltran Corp. "Battery Tender" units are worth every penny.

They now have a 4 amp 6/12v model.

Every so often the local WalMart has their Battery Tenders for $10 to $15 off for a weekend. Worth checking with the store manager on your next visit... ask about upcoming sales.

Over the last 25 years I have purchased a number of real Battery Tenders... I have a 3 amp unit that lives connected to my RV house battery, a 1.25 amp unit that lives on the RV chassis battery. Another 3 amp unit lives under the hood of a friend's 4x4 that gets used occasionally.

The 1.25 amp one I found at a garage sale several years ago for $5, and the 3 amp 6v/12v units were on sale at Wal-Mart one weekend a few years ago for $39 (back then the normal price was $55). Recently Deltran has started making a 4 amp unit that I've seen for about $65-$70.

These days if I see a Battery Tender at a garage sale I buy it - no matter what the amperage. The "Junior" 3/4 amp ones I give to my motorcycle buddies, the 3a or 4 a I will keep, the rest end up at the local ham radio club meeting donation table... I price them at what they cost me... between $5 and $10 - and all money goes to the club.

Mike

[pj48009]

I ditto that. I have two cars in storage when I go to Florida. Both on battery tenders for three to four months. When I don’t use my TT in the summer I pull the battery and put it in my garage on a battery tender. Works great. I know it seems illogical to have my trailer stored all summer but after living in it for three to four months all winter I don’t want to see it for a while.

[Bill Gail]

As you can see from the above posts there are numerous approaches in how to charge and maintain your batteries .

They are all valid methods including what you are currently doing.

Trickle Chargers do work , they just require more monitoring of the battery water levels.

I personally went with the least labor intensive and most cost effective way for me.

Find what works for you .

The important thing is you are aware of the need to maintain the batteries . It always amazes me how many people are surprised in the Spring when their batteries are dead because of neglect.

[scrapperjohn]

Since you are using some kind of charger, I assume you have shore power close. Why not plug rig into shore power & let the on board converter charge batteries ?

[garywilson]

Why a timer? Maintainer...
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

[NYJoe]

I was mistaken calling my charger a Trickle charger, it's the Schumacher maintainer. The reasons for the timer: since I storage the batteries in a heated area in my house, didn't want to have the charger running 24/7 wasting electricity. The timer adds the convenience of not having to physically plug in the charger every few days. I was also concerned with over charging but that's not the case with the maintainer. I asked this question because I was afraid of shortening the battery life due to daily charge cycles. I've been checking voltage just prior to the next cycle and it's been stable at 12.9 v.

[garywilson]

Just plug it in and let it run.
My Schumacher has been plugged in for three years.
Like your stereo, etc, it doesn't use much juice unless it is actually charging.

[l1v3fr33ord1]

Originally Posted by NYJoe

The reasons for the timer: since I storage the batteries in a heated area in my house, didn't want to have the charger running 24/7 wasting electricity.
...
I've been checking voltage just prior to the next cycle and it's been stable at 12.9 v.

A healthy battery, fully-charged and disconnected from loads, will maintain its charge for months; self-discharge rates are something like 5 percent per month at room temperature. Disconnect the timer and the charger, go have a worry-free off-season, and you'll be fine.

If you are worried about following this advice, then you could check the battery voltage or specific gravity in the cells (for a flooded lead-acid battery) once a month, and apply a charger if needed.

[NevadaNick]

I have an enclosed trlr with a maintainer on the battery and a couple of motorcycles with them and have them on timers that come on each day for 2 hours. One of the motorcycles and the enclosed trlr are now 7 years old with the original battery.

[Winemaker2]

As you see above any of the various schemes can work. IMO keeping the battys "fully" charged and not letting them sit at a low SOC for an extended period is the key. The problem with the periodic(monthly +/-) check is that at some point most of us forget and let the V drop.
I have a MH in remote storage and just leave 2 maintainers hooked up & running 24/7 ( 1on chassis, 1 on house bank) My house bank is 8 - 6V GCs and I use a larger 2-4-8A maintainer. Chassis is similar to yours 1.5A. These are multi stage and will switch to float when batty is full with a lower V & A than when needing charge. Maintainers usually do not charge high enough A to require frequent add of water the way fasterm hi A charging does.
At least w my Batty Minder the mfg informed me than when connected but not powered it actually has a small draw on the batty so I just leave it on.
I use mine on multi batty bank but always try to make sure the hook up is balanced... so with 2 battys in parallel + cable should be one batty and - neg cable on the opposite batty.