Ran my Trojans flat

[bcbullet]

Well, I screwed up. The rig has been parked for a couple months but I spent a night in it a month ago just for giggles. Of course I made sure everthing was off before leaving it, but I forgot the damned cell booster. Well of course we have had snow for the last couple weeks and "knowing" everything was off, I was not too worried about clearing the panels off. Today I go in for a quick glance at the Bogart Trimetric and it gave a dull little flicker but no display. I immediately cleared the panels, plugged in the Xantrex charger and display returned.
So have I killed my 6 month old Trojans or will they recover???

 

[LeeRevell]

Check the electrolyte level, are any cells dry? If they have fluid, do you have the hydrometer to check them? Maybe as that fellow in "The Princess Bride" said, "They are mostly dead, not completely dead!"
Might as well try bringing them back, before writing them off.

 

[SternWake]

Cover any dry cells


Charge to 14.8v, adjust upwards for cold temperatures
Wait until amps taper to 2% of 232Ah capacity.  4.6 amps

Dip hydrometer.  1.277 or higher on all 6 cells?

Yes, all is well, damage done but unknown capacity left.

No? Increase voltage to as high as 16.2 for Equalization
Dip cells every 15 minutes until each cell raises to 1.277 or higher.

If it stops rising, terminate 16.2v
If battery temperature gets above 110F terminate 16.2v
Use plenty of ventilation. Protect eyes when dipping hydrometer.

A quality battery that was still relatively healthy before such a slow deep discharge, can recover from this, as long as the batteries did not freeze.  It might take multiple attempts to get specific gravity to 1.277 or higher.

100% depleted, if they froze, they could be goners and should not be recharged.

 

[MrNoodly]

Maybe you need one of those big ass industrial grade throw switches that disconnects the batteries from everything. Then leaving anything else on would be no problem.

 

[bcbullet]

Thanks everyone. Unfortunately until the sun starts shining and I can adjust the charge controller to get the voltage up I am stuck with the my 10 amp "holy crap, it's been raining for a week" back-up Xantrex charger. It has been on for four hours now at a steady 10.3 amps and output has climbed slightly from 12.5 to 12.7 volts. With the "cold" setting it will attempt to reach 15.5 volts. The Trimetric is showing a line through the "% full" status, but I suspect it lost its programming at such low voltage and will need to be reset once (if) I can get the batteries back up. Once the sun is shining I can manually force an equalization charge with it to get it up to the neccessary voltages to try to salvage them. We shall see what tomorrow brings....

 

[John61CT]

Seems it would be worth having/getting a manually controllable power supply / charge source, rather than depending on an automatic "too smart" one.

Suggestions from anyone on a powerful but reasonably priced unit?

 

[SternWake]

10 amps is better than nothing. The xantrax charger will be at 10 amps for quite a while.

The trimetric will likley no read State of charge until the batteries are held up at absorption voltage for a while.

Reset it when you max out specific gravity.

Achieving 16.2volts for an Equaization, is not so easy.

https://vanlivingforum.com/showthread.php?tid=21177

https://www.amazon.com/NES-350-15-S...034&sr=8-1-fkmr0&keywords=meanwell+nes-350-15


One will not able to tell, by voltage alone, if the batteries are still good, recovered.
The Hydrometer is the battery polygraph.

Even if it reads good, one will have to use the batteries as they normally would and see if the voltage they hold overnight in use is still staying above 12.2v easily, or if it sags further than one is used to seeing.

 

[frater secessus]

Seems it would be worth having/getting a manually controllable power supply / charge source, rather than depending on an automatic "too smart" one.

Suggestions from anyone on a powerful but reasonably priced unit?

From my reading the Xantrex charger wasn't on, so it's not like it failed.  The PV were covered in snow so the CC wasn't charging, either.

An LVD would have reduced the damage, I'd think.

[EDIT: maybe you are talking about a general backup plan rather than this case in particular]

 

[bcbullet]

I had a quick look at 0400 on my way to work...Xantrex is still outputting 10.3 amps and now up to 13.7 volts. I am guardedly optimistic that they may not be pooched yet. My fingers are crossed.

 

[LeeRevell]

From my reading the Xantrex charger wasn't on, so it's not like it failed.  The PV were covered in snow so the CC wasn't charging, either.

An LVD would have reduced the damage, I'd think.

[EDIT: maybe you are talking about a general backup plan rather than this case in particular]

What is "LVD"? That term is undefined.

 

[tbair]

What is "LVD"?  That term is undefined.

From context I am guessing Low Voltage Disconnect. It wasn't in my TLA dictionary either so I had to think a bit, painful.

 

[SternWake]

A master disconnect that bypasses the solar would have prevented it.

Low voltage disconnects do have a parasitic draw thast would help the batteries discharge to the 11 volt? threshold at which they disconnect.

 

[bcbullet]

A master disconnect that bypasses the solar would have prevented it.

Low voltage disconnects do have a parasitic draw thast would help the batteries discharge to the 11 volt? threshold at which they disconnect.

I of course figured that I was smart enough to never be in this boat.  :dodgy: Like all the other "nanny" things in life, seatbelts, helmets, air bags etc. you don't need it until you do. Come spring a disconnect will be on the list even though I poo-pooed installing one not six months ago.

 

[LeeRevell]

I occasionally use my minivan's built-in "Master Disconnect", to isolate the battery.
Takes about one minute to pull the terminal, I keep the correct wrench in my center console box.

 

[frater secessus]

Low Voltage Disconnect.

 

[bcbullet]

OP here....much to my amazement, they are perking along fine again. We have had enough sun the last couple of days that I was able to absorb charge at 14.8, high finish to16.2, down to float at 13.5 and then an equalize charge at 16.2 again using the amazing (but fiddly to program) Bogart Trimetric.
I don't know the long term effects yet, but considering they sat dead flat for about a week at -10C and then another week at -20C (guesses here on the time factor but not the temperatures) I am truly amazed. Time will tell just how much they got beat up, but at this point they SEEM fine.

 

[LeeRevell]

Those thicker heavy duty plates make it more forgiving of such mistakes. Just treat them better from here on out!

 

[bcbullet]

I have been giving them tender loving care....never under 80%. Sometimes you hurt the ones you love!

 

[SternWake]

Good news. It is hard to judge performance until you use them hard, but a good sign they seem fine now.

OTC4916

https://www.amazon.com/OTC-4619-Professional-Battery-Hydrometer/dp/B0050SFVHO

It is really hard to judge by voltage alone.
My old flooded battery is not very happy anymore, beat to heck, yet it stil holds 12.78 for weeks after a full charge, and its Specific gravity on all but one cell reads good. It would fail to meet 80% of its original capacity.

I bet it would fail to meet 70% of original capacity.

If you never drain them below 80% it will take a long long time for you to notice any capacity loss/ performance attenuation.
if you really wanted to make sure, get the hydrometer and do the 16.2 volts again and ensure all cells are indeed 1.277 or higher. Warm and fuzzies can be quite satifying.

 

[bcbullet]

Good news.  It is hard to judge performance until you use them hard, but a good sign they seem fine now.

OTC4916

https://www.amazon.com/OTC-4619-Professional-Battery-Hydrometer/dp/B0050SFVHO

It is really hard to judge by voltage alone.
My old flooded battery is not very happy anymore, beat to heck, yet it stil holds 12.78 for weeks after a full charge, and its Specific gravity on all but one cell reads good.  It would fail to meet 80% of its original capacity.

I bet it would fail to meet 70% of original capacity.

If you never drain them below 80% it will take a long long time for you to notice any capacity loss/ performance attenuation.  
if you really wanted to make sure, get the hydrometer and do the 16.2 volts again and ensure all cells are indeed 1.277 or higher.  Warm and fuzzies can be quite satifying.

Thanks Sternwake...that is on my list for the weekend.