Today was a nice enough day to get at my trailer. I am in the process of charging all of my various batteries for the summer. One of them is my deep cell for one of my trailers. I couldn't remember if I had actually removed it, or even disconnected it from my trailer.Turns out, I didn't. It was still hooked up to the trailer. After disconnecting it, and bringing it into my garage, I tried to put it on charge. The smart charger I have would not turn on. So, I connected another battery to the dead battery, and then hooked up the charger to the dead battery. That got it going. I disconnected the other battery.The trailer battery is now on charge, and hopefully is salvageable.

Of it discharged and froze, it's probably toast.

SidecarFlip wrote:Of it discharged and froze, it's probably toast.That is my worry. I will give it a chance to charge before I accept it is toast.

Do you have any idea how many amps the battery is accepting, and for how long, before voltage rises to the mid 14's??I got a call from a neighbor the other night. He said he wanted a battery reccommendation as his battery just died and just caused his new to him vehicle to stall while driving home, sitting at a traffic light. He got a jump froma jumper pack and was able to drive the mile home.I said hold on lets check the charging system. It was as I suspected, not charging.The battery was 12.06v when I checked.KNowing it was going to be outide overnight with some possible rain, I got my Schumacher 'smart' charger, even though it is Bipolar. Instead of my power supply which I trust much much more.I set it on the 12 amp setting and watched the volts and amps.on the 12 amp setting it was outputting 14 amps, and the battery voltage rose slowly from 12.06 to 13.41 in 5 minutes.if 14 amps had allowed voltage to quickly rise to 14.7v, it would say to me the battery is sulfated with little remaining capacity.After 5 minutes I disconnected the charger and had him start the engine. It was not charging the battery.I set schumacher for 25 amps and let it go, 26 amps had voltage rise to 13.8v in about 10 minutes. I declared the ~ 65Ah Deka starting battery, is still strong. I wound up lowering it back to 12 amps and let it go overnight. the watt meter said it had accepted 59AH in those 12 hours before I removed the charger.The voltage 2 hours after removing the charger was still 13.4v.The vehicle had never cranked to life faster since he bought it.I found some loose connections, and was able to get 14.4v with engine running.Watching how many amps flow at a voltage is extremely enlightening as to battery state of charge and state of health, but almost nobody seems to realize this, and just think voltage alone tells everything, or the lights on a charger say all is well.So your battery could have been discharged below 10.5v(100% discharged) and froze, and any attempts to recharge it could be fruitless, but if you saw battery voltage slowly only climb as it accepted 12 amps hour after hour, that would say other wise.But without seeing how much amperage is flowing at that voltage, you get to trust the internet and some smart charger's reading.So many smart chargers will see a voltage when first hooked up and declare a state of charge as a percentage. This % can be way out of line with reality.However an Ammeter display along with a voltage display would be extremely enlightening and harly much more $$ to incorporate into the charger.For thosreaders to whome this makes sense, this simple device can allow you to see what your plug in garage charer is actually doing:14$ inline wattmeterIt will handle upto 25 amps continuous without issue and will allow you to see just how smart, or dumb, your garage charger is.A depleted battery which accepts a lot of wattage for a while without heatinvg excessively is a battery still capable of preforming its duty, once recharged.A depleted battery whose voltage quickly climbs to the mid 14s with less than a dozen amps, is likely done and done, and worth the core charge only.

If someone paid me ten grand to design a smart battery charger that only had to meet the idiocy of today's standards of playing "Tickle Me Elmo" until a light blinks. I'd insist on having the rights to naming the product.And, it shall be modeled...The Terminator

oops might have damaged my battery | Good Sam Community

16 Replies

Boon_Docker
Explorer III
Mar 18, 2018
Almot wrote:
swimmer_spe wrote:
I couldn't remember if I had actually removed it, or even disconnected it from my trailer.

Turns out, I didn't. It was still hooked up to the trailer.

You don't have to disconnect battery from the trailer - only from the trailer loads.

Though it is desirable to remove it to warmer place for winter, if your temps are below freezing.

Less self discharge in temps below freezing compared to a warm place.

My (fully charged and disconnected) 6 year old batteries stay outside below freezing for 6 months each year and they lose about 0.2 volts charge in that time period.
Almot
Explorer III
Mar 17, 2018
That's why I said "from trailer loads". Anything that draws power.
If there is no switch that does this, - install one. Mex picture shows one of (cheap) available models.

Though the problem with wet cells is that they self-discharge notably without any loads, if left without maintenance charger for more than 3-4 months.
swimmer_spe
Explorer
Mar 17, 2018
Almot wrote:
swimmer_spe wrote:
I couldn't remember if I had actually removed it, or even disconnected it from my trailer.

Turns out, I didn't. It was still hooked up to the trailer.

You don't have to disconnect battery from the trailer - only from the trailer loads.

Though it is desirable to remove it to warmer place for winter, if your temps are below freezing.

The battery will discharge due to the CO and propane detector.
MEXICOWANDERER
Explorer
Mar 17, 2018

Click...

I've gotten older, so I use timers, and notes. I can't afford new stuff
Almot
Explorer III
Mar 17, 2018
swimmer_spe wrote:
I couldn't remember if I had actually removed it, or even disconnected it from my trailer.

Turns out, I didn't. It was still hooked up to the trailer.

You don't have to disconnect battery from the trailer - only from the trailer loads.

Though it is desirable to remove it to warmer place for winter, if your temps are below freezing.
time2roll
Nomad
Mar 17, 2018
swimmer_spe wrote:
OP here.

I do not know for sure it was frozen or had sulfated.
Does it even hold a charge sitting disconnected?
Then dip it with a hydrometer to know where you are at.
brulaz
Explorer
Mar 17, 2018
swimmer_spe wrote:
OP here.

I do not know for sure it was frozen or had sulfated.

You store it in Sudbury, Northern Ontario (where it gets REALLY cold over winter)?

Maybe after hunting last November sometime, or earlier ( more than 4 months ago)?

You didn't disconnect the battery so the trailer's background loads would draw down the battery (prolly after a few weeks)?

I'm thinking "toast". But follow landyacht's instructions and monitor the amps while attempting to charge. That will tell the tale.
swimmer_spe
Explorer
Mar 17, 2018
OP here.

I do not know for sure it was frozen or had sulfated.
wa8yxm
Explorer III
Mar 17, 2018
Three types of batteries (really 2.1)

1: Starting: Discharged that far = TOAST
2: MARINE/deep cycle (The .1) Most likely toast
3: TRUE DEEP CYCLE (Like a pair of GC-2's or a GC-12) Fair chance you aged it some but it may recover if it did not freeze.

Wish I could give better news.
ViewOfAKindArt_
Explorer
Mar 17, 2018
I left a battery to freeze one season, and it charged back up to be able to use it, and at test showed a healthy charge but eventually had to replace for poor performance 1 year later