Battery Equalisation Questions?

[Tim Good]

1. People say you should turn off all you 12v electrics before equalising as the voltage can go up to 15.8v. Is it really necessary to turn them off given that my charger on shore power will kick out 14.5v?

2. My solar panels have an equalisation mode via the Victron controller. Is this realistically going to work well and should I take the same precautions like being present all the time it is happening, ventilation, turning off 12v electrics if I set the Victron to equalise.

3. Consensus is always be present while equalising and not at night whilst asleep but that's actually difficult to find the time for that. Thoughts?

4. How often should you equalise or what I really mean is who equalises regularly and sees a real benefit?

 

[Tim Good]

Maybe this missed everyone by. Does anyone have any thoughts on these Q's?

 

[lw395]

1) You'd have to RTFM for every piece of kit you intend to leave on. I can see potential issues with LEDs, motors and anything that monitors its input voltage like diesel heaters and fridges. Ordinary 12V bulbs may blow.
2) if it's pushing the voltage up to similar levels, take the same precautions.
3) I don't disagree with the consensus.
4) Should not be necessary very often. Very little benefit on a healthy battery that has not been heavily discharged. Real benefit as the batteries get older.

 

[RichardS]

My CTek has a "re-condition" cycle which I think is the same thing.

I didn't answer before as I'm not totally sure what real benefit it provides and I've only used it on car batteries but it does seem to increase the capacity of old batteries and gives them a burst of life. I tend to use it on my car batteries once a year. I just leave them overnight.

Richard

 

[GHA]

1. People say you should turn off all you 12v electrics before equalising as the voltage can go up to 15.8v. Is it really necessary to turn them off given that my charger on shore power will kick out 14.5v?

2. My solar panels have an equalisation mode via the Victron controller. Is this realistically going to work well and should I take the same precautions like being present all the time it is happening, ventilation, turning off 12v electrics if I set the Victron to equalise.

3. Consensus is always be present while equalising and not at night whilst asleep but that's actually difficult to find the time for that. Thoughts?

4. How often should you equalise or what I really mean is who equalises regularly and sees a real benefit?

What batteries do you have?

1 - Probably well worth being careful, and check the manuals. I go for absorption at 14.8v with no probs yet but some of the cheapo LEDs flash a bit so they might not be long for this world.

2 - Equalising off solar just ain't gonna happen IMHO, takes long enough just to get back to full. Think we have the same victron (it's great!)

3 - best to be close I think, with the batteries bubbling away. Even high absorption can set off my gas CO alarm.

4 - How often - when I can (2 x t105, fantastic batteries!) ! Which isn't very often given it's either in a marina or running the genny for hours. Trojan recommend every 30 days, when the SG is low or when the cells SG varies by more than 0.030.

"sees a real benefit?" Probably no one on here has even done a proper temperature controlled capacity test, quantifying benefit is next to impossible for us lot

 

[ltcom]

Plevier (guru of batteries on this forum) stated that equalisation (needed to stop acid stratification) used to be used a lot on stationary batteries 3 foot tall, but should not be needed often on boat batteries (owing to movement of battery).
So probably only needed if batteries are showing the beginnings of lower performance.
More food for thought:
This article
http://www.upsbatterycenter.com/blog/understanding-acid-stratification-lead-acid-batteries/
states:
"Stratification also occurs if the battery charge is regularly around 80-85%, not fully charged."

 

[Plevier]

Equalisation is not just to remove stratification, but that is one of its purposes on tall stationary batteries.
I do maintain that stratification is highly improbable on boat/car/aircraft batteries due to movement and their small height.
The trigger for equalisation charging should be unequal s.g. or voltage between individual cells - which you can't measure on most modern vehicle batteries because they are sealed.
Perceptible decline in performance means a more serious problem or just general wear and tear.

 

[macd]

The trigger for equalisation charging should be unequal s.g. or voltage between individual cells - which you can't measure on most modern vehicle batteries because they are sealed.

That's key, northcave. You don't indicate what batteries you have, but Trojan's general advice for flooded batteries is to equalize "only when batteries have low specific gravity, below 1.250 or wide ranging specific gravity, 0.030, after fully charging a battery." (My bolds.)

If they don't need it, why go to the trouble?

On the subject of monitoring during equalization, Trojan are very clear that you should measure the specific gravity hourly and discontinue equalization charging when the SG no longer rises. Automated equalization cycles cannot do this.

 

[GHA]

That's key, northcave. You don't indicate what batteries you have, but Trojan's general advice for flooded batteries is to equalize "only when batteries have low specific gravity, below 1.250 or wide ranging specific gravity, 0.030, after fully charging a battery." (My bolds.)

If they don't need it, why go to the trouble?

On a cruising boat where getting to full charge again every cycle is pretty much impossible there's a lot of literature pointing towards the benefits of an equalising charge now and again, not so much to do with stratification but to hopefully break up slowly hardening lead sulfate.

First up on google...

http://www.cruzpro.com/batmaint.html

 

[Plevier]

On a cruising boat where getting to full charge again every cycle is pretty much impossible there's a lot of literature pointing towards the benefits of an equalising charge now and again, not so much to do with stratification but to hopefully break up slowly hardening lead sulfate.

First up on google...

http://www.cruzpro.com/batmaint.html

Yes definitely.
Equalisation charging is alternatively known as boost charging, a more descriptive term for this case.

 

[Venus1]

On the topic of boost charging to break up lead sulphate, would anyone care to give an opinion on "Megapulse"? I think it gives regular short term boosts..

 

[lw395]

On the topic of boost charging to break up lead sulphate, would anyone care to give an opinion on "Megapulse"? I think it gives regular short term boosts..

I don't know about the megapulse specifically, but, I've played around with a desulphator circuit which uses fast pulses of quite high voltage.
My experience is that fairly dead batteries can be made a bit more useful. An old car battery was revived enough to run an inverter for a short while.
Which was handy.
But no great improvement on motorbike batteries which have become weak for starting the bike.

 

[GHA]

On the topic of boost charging to break up lead sulphate, would anyone care to give an opinion on "Megapulse"? I think it gives regular short term boosts..

This might be of interest.... Old so the image link is not there anymore...

http://www.cruisersforum.com/forums...-flooded-cell-batteries-12707.html#post132464

You'll be interested to know that after almost six months of testing using the above methodology, we decided to equalize the T-105s ONE TIME to see what would happen. Presto...the results were much more positive than had been the pulsing/charging/discharging over the previous six months.

 

[macd]

On a cruising boat where getting to full charge again every cycle is pretty much impossible there's a lot of literature pointing towards the benefits of an equalising charge now and again, not so much to do with stratification but to hopefully break up slowly hardening lead sulfate.

I'm sure that's right, which is why I was careful to put Trojan's "after fully charging" in bold.

That said, isn't it likely that people prepared to go to the trouble of equalizing might also go to some lengths to ensure that regularly reaching full charge is also possible? We certainly reach 100% charge (as measured by SG), on almost a daily basis. But then we sail in an area where energy is beamed down on us with similar regularity.

 

[GHA]

I'm sure that's right, which is why I was careful to put Trojan's "after fully charging" in bold.

That said, isn't it likely that people prepared to go to the trouble of equalizing might also go to some lengths to ensure that regularly reaching full charge is also possible? We certainly reach 100% charge (as measured by SG), on almost a daily basis. But then we sail in an area where energy is beamed down on us with similar regularity.

I suspect few cruising boats get all the way back to 100% even half the time, you are one of the lucky ones

Even with low usage, lots sun & 300w solar I struggle a bit getting all the way back up, takes ages. Cloudy yesterday morning & this morning so should dig out the honda genny really if this lasts any longer.

With "If they don't need it, why go to the trouble?" - how could you tell if there some sulfation starting? Is a SG difference between cells a good enough indicator?

Zooming out I think there are so many variables involved and little real data, getting beyond generalisations is difficult with cruising boat batteries, with equalisation at a google educated guess - for open led acid it seems almost certainly a *good thing* once in a while. What are the downsides? Tiny bit of corrosion maybe?

http://batteryuniversity.com/learn/article/equalizing_charge
http://shop.pkys.com/Battery-Equalization_ep_44.html

Being a bit voltage & SOC obsessed probably helps as well

 

[macd]

Being a bit voltage & SOC obsessed probably helps as well

I used to enjoy watching telly now and again. Then I got my first battery monitor...

 

[GHA]

I used to enjoy watching telly now and again. Then I got my first battery monitor...

Yay , sun's out!

Double edged sword though, panel efficiency goes down on the heat & fridge duty cycle goes up...

Still won't get all the way today though

 

[PaulRainbow]

I used to enjoy watching telly now and again. Then I got my first battery monitor...

I have the best of both Worlds.

My battery and solar monitors are connected to a laptop via USB, the laptop is connected to the TV via HDMI. I can sit watching the monitors on the telly

Hmmm...... perhaps i need to speak to a professional :hororr:

 

[GHA]

I have the best of both Worlds.

My battery and solar monitors are connected to a laptop via USB, the laptop is connected to the TV via HDMI. I can sit watching the monitors on the telly

Hmmm...... perhaps i need to speak to a professional :hororr:

Seek help, still on cables!!?? You mean you can't see it all on a tablet over wifi on a web page without having to get out of bed?

This might be getting a bit out of control, now my batteries now send a tweet once a minute...

https://twitter.com/MyBoatData

 

[pvb]

I'm happy to confess that, in my 45+ years of boating, I've never once equalised my batteries. Despite this, they typically have lasted 8+ years.