Battery fully discharge

maverickofpoole

maverickofpoole

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Poole....there's a surprise :-)
www.pbsbac.co.uk
Last time I used the boat I forgot to connect the shore power. I also never turned off all the electrical items on the boat with the result being my house battery was fully drained and I mean totally. The starter battery was ok and started both engines no problem. The batteries are both a year old but I am thinking that I probably need to renew the house battery. I have put it back on charge to see what happens but after reading some internet stuff I am not hopeful

So my question is should I try the battery to see if it holds a charge, renew the house or renew both?

Thoughts please and thanks in advance

Martin
 
Some battery chargers have a "reconditioning" mode, e.g those wonderful Ctek chargers.

Worth trying before you ditch them, as it deals with sulfation problems.
 
Ive got a Ctek conditioning charger which has recovered a leisure battery that i accidentally totally discharged. But i think it depends on how good the battery is to start with if it can be recovered or not. Any over 2 years old i wouldnt bother trying tbh and just replace.

As your battery is only a year old, I would give it a charge for say 48 hours, take it off charge and see how the voltage stays up with no load on. Then i would put a known load on and see how the voltage drops over a period of time.
You may be lucky and the battery may be recoverable.
 
I have a quick 3 stage charger, not sure if these are much good but I think I'll leave it on charge for a couple of days then do as Oscar 24 says. If it holds up great but if not I'll get another. One of my fears afloat is losing power whilst away.

Thanks all for your input, it really is appreciated
 
As your local to me, your welcome to borrow my Ctek MXS 7 charger and try it in re gen mode.
PM me if you want to try it, regards peter
 
from last months experience trying to revive 3 batteries, I'd definitely forget your 3stage charger and take Oscar's offer!

I had 2X180Ah starter batteries in series for 24V (4yo that led a v.easy life for the first 3yrs), I was taking from the first one 12V to start/run the generator. This (a definitely bad practice) combined with the sorry state of the generator (lots of cranking to fire up) meant that I buggered a bit this battery. Since the charger (a Victron centaur) was a 24V one the buggered battery helped the healthy battery to also fall into a sorry state.
Charging with the Victron was no good.
Tried a simple 3stage 12V charger on each battery, leaving the charged one for a day while charging the other, no luck they both showed good voltage when plugged and a few hours after unplugged, but trying to turn the starter on my 2cyl yanmar gen engine would not work, maybe 1-2 turns of the flywheel if lucky. In series, the 6cyl main engines starter would just click...
Tried a small smartwhatever victron 12V with regenerate mode on each battery and a CCA meter afterwards, the good one did 140CA, the bad even less. Both scrapped.

Had a problem with a car battery, brand new in Dec, left connected on a dead engined car for 5months, wouldn't charge afterwards after 2days on normal 3stage charger 2lt engine starter wouldnt even click.
Tried the victron, revived it in a day, battery's fine on the car now.

so ymmv, but your only chance is reviving with a suitable charger.

V.
 
charge the battery for a day or more,
and measure the DC voltage,
with the charger off, it should show 12,2..12,3 Volt. (or more)
wait half an hour, should still be 12,2V or more,

if it measures below 12,0V DC, the battery is knackered
if it measures 12,2v you're ok.
 
yeah, charge it up and use it.
You've probably done some damage but don't worry about replacing it until you're not getting the service you need from it.
If it's completely dead you'll know soon enough, otherwise it may have reduced capacity but that will still be probably more than you need.

It's only your leisure battery, worst case scenario you need to start your engine, or your milk is slightly warm in the morning :-)
 
Just an update.

I left the boat on charge for 2 full days then disconnected the shore power for a day. Went out on the boat Friday evening had all the electronics including fridge nav gear and radios. Slept on the boat Friday eve then went out all day saturday before returning to the marina and reconnecting to shore power. Short story is I appear to have dodged needing a new battery.

Thanks to everyone for their input

Martin
 
Thats good to hear Martin, :)
I would still keep an eye on the battery for the next few weeks checking the voltage doesnt go AWOL on you.
If you need the Ctek just PM me
Regards
Peter
 
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