Battery equalization

[mokiemike]

I have a three stage rgulator for my alternator. It has instructions for useing a little jumper ( included ) and instructions for equalizing. I've never done it but would like to. Anyone with experience in this proceedure out there positive or negative? I'm a little leary of such a thing having never done it and not knowing anyone who has. Thanks
ike

[camaraderie]

Sure...do it ONLY if you have WET cells...never on a sealed battery! Full time cruisers need to do this once every month or two to remove sulfation from less than full charging. Those on dockside quality 3 stage chargers (not alternators!!) need EQ far less often. Simply follow the instructions to set up the EQ process on your charger, remove the battery caps, top up with distilled water and have good ventilation for the 6-8 hours EQ will take on a decent sized house bank.
Doing EQ off of an alternator and running your diesel for 6 hours is NOT RECOMMENDED!

[gavinandrebecca]

Can i be so bold as to add..... that equalising is also to get the battery acid even through out the cell. As you add distilled water, it floats on top , plus the acid (being heavier) sinks to the bottom. This is called stratifying. As the electricity is produced via a chemical reaction btween cathode and anode via acid, the efficiency is higher where the acid is strongest, eg on the bottom of an un-equalised battery.This causes the battery to 'wear out' unevenly and also lowers the life of cell, and they work less effiently. When EQ take the batteries up to the "boil",which should be 14.4V on 12V system, for an hour. this should circulate the acid such that specific gravity is even through out the cell. Other time charge at 13.8ishV. Oh and the ambient temperature makes a difference to when the batterries bubble

[MidLandOne]

I personally don't think an equalisation charge is of any merit except perhaps if the batteries have been consistently under charged so that sulphates build in the plates.

Trojan do not seem to recommend equalising charges for their batteries except when the specific gravity of the electrolyte remains low after charging or if there is wide disparity in the SG over the cells. Sounds like last resort stuff to me.

We use Trojan batteries and never equalise them (even to try and extend their life as figure if they have a problem they are near the end of it) and have always had long service (last lot 10 years). But we go out of our way to avoid deep discharges or leaving the batteries only partially charged - the latter, for wet lead acid deep cycle batteries, meaning the ability to maintain fourteen point whatever bulk charge volts very deep into the charge.

[camaraderie]

Gavin...NORMAL bulk charging voltage for 12V wet cells is 14.4-14.5 volts and EQ charge is generally around 15.5-16v so you can actually get a boil on. In every other respect your post is correct.

Midland...since most people at a dock and plugged into a charger don't have Trojans and don't have any way of measureing the specific gravity of their batteries...the general recommendation is for EQ once every 6 months. In cruising situations batteries are often not fully charged daily so the EQ recommendation goes up. In actuallity the techinical requirement for EQ'ing batteries IF you can measure specific gravity is:
Equalization is required when the cell specific gravities between cells vary from highest to lowest by +/- 0.015 (1.245 - 1.260 at full charge).
Since you are quite a bit more rigorous tha most in both your selection of batteries and your charging routine, you can avoid the EQ routine until something appears amiss.

[MidLandOne]

Originally Posted by camaraderie

Midland...since most people at a dock and plugged into a charger don't have Trojans and don't have any way of measureing the specific gravity of their batteries...the general recommendation is for EQ once every 6 months. In cruising situations batteries are often not fully charged daily so the EQ recommendation goes up...
...Since you are quite a bit more rigorous tha most in both your selection of batteries and your charging routine, you can avoid the EQ routine until something appears amiss.

I did say I personally don't think an equalisation charge is of any merit except perhaps if the batteries have been consistently under charged... So actually no disagreement there .

So if one consistently undercharges then equalisation may help, but it will not undo all the damage from undercharging - consistent undercharging is a road to hell for the batteries, due to sulphation, equalisation practiced or not.

Also, and often not stated, equalisation is just extremely inconvenient for most of us as for the 8-12 hours of the equalisation charge until one is sure that the cell SG's have stabilised one has to keep all consumers not rated at the equalisation voltage (normally all on board) off the batteries meaning a long period of sitting on a dead ship - assuming, of course, one is not prepared to just leave the boat to itself during the process .

So, in my view, the best approach is to learn to look after the batteries instead, and that is something that is very easy to do, even when cruising for long periods well away from shore power and a very easy task of no effort at all if in a marina - just have to make it a habit.

Am not sure of why the inference that cheaper batteries than Trojans require routine equalisation. Personally, considering the build of cheaper batteries, I would have thought routine equalisation would be less useful for cheaper batteries, if it were to be required for any.

I would suggest that being able to measure SG is of little importance in taking ordinary good care of the batteries. As the case is though I do have a very good hydrometer - useful, obviously, if something goes wrong before the end of the expected reasonable life of the batteries but fortunately I can't speak from experience there and it has never been used .

[bobmcgov]

Equalization is most useful when you have batteries in parallel, slightly less so in series arrays. Done religiously, it can reverse sulfation while it's still reversible. But if a battery is rode hard all the time, or if the sufates have started to build up to major thickness, EQ prolly won't save them. And equalizing too hot for too long will kill them prematurely, especially in batteries with thinner plates. (My lead's 1/4" thick, no worries there.... )

I actually endorse equalizing more often for shorter times when using small batts. My charge controllers (Outback Bergey, Trace/Xantrax) all use a default 1 hr EQ cycle, once a month; tho I'd do it at least twice or thrice a month with smaller banks. 10,000 AH at 24V has its advantages, heheh. Need some serious wind to get those buggers boiling.

[gc1111]

The Trojan battery company has a good Web site. See:
http://www.trojan-battery.com/Tech-S...qualizing.aspx
They have criteria for when equalization is needed and how to do it. They also have good info on normal chargers and charging.

[mokiemike]

thanks for the feedback, most helplul;I have T105's and thanks too for the the direction to the Trojan website, I hadn't thought of looking there.
Mike