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Further to this, I've been sent a PM urging caution re equalizing AGM batts. In this case, the NZ agent has insisted on an equalization schedule,  and wanted monthly and 15.2v. So this is what this is set to. But again I urge you to read the PDS for your batts, and do what that says. Dont take anyone's word for the settings, the manufacturers know their products, and also carry the warranty!

If you are going to equalize, temp sensing is essential! IMO.

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Haha! Yeah, nah, would like too.🤫

But not in my DNA, sadly.

Have to obsess about something.

Seems  I’m just getting to know my batteries after five years. Obviously a slow 

learner. Just as well FLA’s are damn near idiot proof.

Given up on Firefly carbons as I’d need three to equal current setup and they are 31kg each. Besides my existing batteries are fine. (Apart from slow charge & smell)


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 AGM and GEL are also Lead Acid batteries, but have a different means of covering the plates with Acid.
I will start with GEL batteries, because the rule is pure and simple. Gell should not ever be Equalization charged. Unless you have a very specific instruction from the manufacturer that says you can . As soon as Gel gasses, it is shot.

Not all AGM's can be EQ charged. As IT said, check with the manufacturer. The battery has to be designed for this to be able to be done safely. It requires specific design in the interplate connections. This usually results in more expensive batteries and thus tends to be found in the Brands that have big reputations and prices.

FLA MUST be EQ charged regularly.
     All lead acid batteries sulfate. This is a natural occurrence every time you discharge. The electrolyte in Lead Acid battery is Sulphuric Acid. A brand new fully charged battery is lead and sulfuric acid. As the battery starts to discharge, a chemical reaction between the lead and acid produces Lead Sulphate and electrical energy. Lead sulfate is a soft material that naturally covers both positive and negative plates. The deeper the discharge, the more lead sulfate will cover the plates. Once the load is turned off and it is time to recharge, lead sulfate is easily converted back into lead and sulfuric acid. This is why it is important to charge batteries back to 100%.
If you don’t you will not convert all the lead sulfate back into the active material. If a lead acid battery is not immediately recharged, the lead sulfate will begin to form hard crystals, which cannot be reconverted back to soft Sulphate. Thus the longer and more frequently the Battery is discharged and the longer the battery is not allowed to be fully charged, the less energy the battery will be able to reproduce.
Standard recharging will never bring an LA Battery back up to full charge and thus will always be undergoing sulpation and creating crystals,
Big heavy FLA batteries can require an EQ charge of up to 8hrs for them to be fully recharged.
You can usually tell if your batteries are sulfated when the open circuit voltage (OCV) is low. To measure the OC Voltage, fully charge the batteries. Then leave to sit for at least 10hrs, 24hrs preferable. A fully charged good condition battery should be 12.8 volts or higher. Some can read 13+ Volts. A sulfated battery will be “finished” charging, yet only have an OC Voltage of 12.2-12.5 volts. It will give very little energy back when under load.

It is a good point to add, when battery capacity is down, a line is eventually crossed between the economics of energy in and energy returned. If you didn't pay for the Power being pushed into the battery during charge, it isn't so important. But if you do, there is not economical point in supply say 1000Watts of energy in to the battery and getting only 100Watts of energy back out.

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Yep. I equalize at 15.5v  for 5hrs. (4x 6v FLA's)

But its a pain in arse. 

Also my batteries start absorb at 14.4v and are not full until 14.85v. (On regular charging)

So much for the legendary "constant voltage". I suppose relative to "bulk" its constant.

Back to 12.8x rested. And THAT take hrs.

Rehashing it,  now I'm wanting Pb/carbons again. Or Lithiums.

I can charge @ 180A indefinitely with hardware on hand.


Actually FLA's are quite amazing that they appear sluggish and you equalize them and they seem new again.

I still love to hate them.

I need to get out more.


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15 hours ago, Sabre said:

Note to self. Dont read posts on battery management. Keep head in sand, cross fingers and all will be well 👍

Ditto, although I'd add another item to my management plan 

  1. Head in sand
  2. Fingers crossed
  3. Don't let them go flat

So far its working a treat


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Mastervolt are usually ok. But here is a little test. Ask any supplier for a peukerts number and a PDS (Product data sheet) for that particular battery. If they cannot provide them, then they are low end "consumer" batts, not commercial level.

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