New trojans

[daletournier]

My batteries decided to retire early yesterday but fortunately I was able to buy decent batteries here in the Seychelles.

I've just installed some Trojan T105's.
They have all come of the shelf sitting around 6. 05v, abit low.

What's the best practice here. Should I charge normally first up or equalise them straight of the bat seeing that they are abit low?

Thanks in advance.

[Maine Sail]

Originally Posted by daletournier

My batteries decided to retire early yesterday but fortunately I was able to buy decent batteries here in the Seychelles.

I've just installed some Trojan T105's.
They have all come of the shelf sitting around 6. 05v, abit low.

What's the best practice here. Should I charge normally first up or equalise them straight of the bat seeing that they are abit low?

Thanks in advance.

Charge to full with absorption voltage temp compensated to 14.8V at 80F. When current drops to less than 1% of Ah capacity at 14.8V, or stops dropping and stabilizes, you can then boost the voltage to 15.5V - 16V depending upon battery temp...

[daletournier]

Thanks Mainsail, much appreciated, was hoping you'd comment.

[daletournier]

One more question mainsail, purely out of curiosity.

Obviously these batteries have self discharged whilst in storage. They have do. There were literally hundreds and hundreds of them on pallets. There's something like 3000 golf carts in the Seychelles (apparently).

Now I'm not sure how long they were sitting on pallets in the US then were sitting on ships now sitting in a warehouse in the Seychelles.

My question is, I assume this is normal? These batteries are already under full capacity due to sulphation from storage time and transit time therefore none of the traditional lead acid batteries sold are able to reach full soc as they are slightly damaged due to self discharge as a result of the sitting time?

As a bank once all connected (675amp hour) they measured 12.05v.

Once again thanks for your advice.

[robert sailor]

I have purchased batteries in similar conditions and gave then an equalization charge every few weeks to begin with and I got decent life out of them. Just dont let the water get low as that can expose the tops of the plates and you'll have sulphation in an instant. Check water levels every 30 days. You can hit those batteries with fairly high absorption charge rates without hurting them.

[john61ct]

Breaking in period if possible. keep amps rate lower both in and out, say .15C max for a dozen or 20 cycles

Once truly full and equalized, you could draw down at .05C until 10.5V (no lower!) and immediately recharge.

This will help with initial capacity and longevity.

Assuming you care for them well otherwise.

[DotDun]

Originally Posted by daletournier

One more question mainsail, purely out of curiosity.

Obviously these batteries have self discharged whilst in storage. They have do. There were literally hundreds and hundreds of them on pallets. There's something like 3000 golf carts in the Seychelles (apparently).

Now I'm not sure how long they were sitting on pallets in the US then were sitting on ships now sitting in a warehouse in the Seychelles.

My question is, I assume this is normal? These batteries are already under full capacity due to sulphation from storage time and transit time therefore none of the traditional lead acid batteries sold are able to reach full soc as they are slightly damaged due to self discharge as a result of the sitting time?

As a bank once all connected (675amp hour) they measured 12.05v.

Once again thanks for your advice.

They have a date code on them.

month is a letter (E = May), single number is the year (8 = 2018)

[daveNZ]

Two question on voltage levels.

Q1. When 10.5V is mentioned endpoint for a discharge test, that surely is 'under load'.

(Out of interest I just completed a test; 130Ah USBattery, 3.8A load for the test -very typical for my fridge - battery went down to 9.5V at end of test (I missed the 10.5 point while I was away from garage) then back to 11.87V overnight.
This puts the battery after discharge at about 35%SOC.
Whereas S.G. puts the battery at about 15% to 25%...variation between cells!), so a bit uneven and plan to do an equalisation, or two!) The battery is 3 years old, always on small solar; probably not enough!! (My BM always says battery reaches 100% ..... I say "bull%^&"!! even with aggressive parameters)

Q2. My main question, when people refer to 'should not discharge below 12.2V; i.e.50% SOC', that surely is a resting voltage level. So how, when afloat, do you judge 12.2V? In my case the 'under load' V would be about 0.3V lower, say 11.9V

[john61ct]

Originally Posted by daveNZ

Q1. When 10.5V is mentioned endpoint for a discharge test, that surely is 'under load'.

Yes, standard stateside is .05C discharge current, the 20-hour rate.

> 130Ah USBattery, 3.8A load for the test -very typical for my fridge - battery went down to 9.5V at end of test

You may well have lost a fair number of cycle's lifetime. Better to put an LVD + alarm in if you're going to walk away.

You don't even want the batt to sit at 10.5V any longer than necessary, get it recharging immediately after hitting that 10.5 point.

> This puts the battery after discharge at about 35% SOC.

Compared to what? What gives you that idea? 10.5V at a low discharge rate is functionally **zero** SoC.

The whole point of the test for SoH is to determine the *actual* AH capacity; if that is 70-75% of rated AH, the batt is scrap (industry spec is 80%, but non-bluwater consumers can push past that, a bit.

> My BM always says battery reaches 100% ..... I say "bull%^&"!! even with aggressive parameters

100% SoC is when trailing current at Absorb V falls to endAmps spec, usually ~.005C

Never rely on an AH counter for that, it is **your** job to tell it when charge is finished, reset it at 100% Full frequently to keep it accurate. Ideally every cycle.

> My main question, when people refer to 'should not discharge below 12.2V; i.e.50% SOC', that surely is a resting voltage level. So how, when afloat, do you judge 12.2V? In my case the 'under load' V would be about 0.3V lower, say 11.9V

You can/should never rely on voltage or SG for SoC while cycling.

If your BM is properly reset and calibrated, the actual AH capacity kept updated as that declines, you just stop discharging when it reads 45-50% down.

So, if your **used-to-be** 130AH batt is now actually 90AH, you only have 45AH usable to work with at 50%.

And your batt is at end of life, in need of replacement before heading out for any extended cruising.

[robinco]

Originally Posted by Maine Sail

Charge to full with absorption voltage temp compensated to 14.8V at 80F. When current drops to less than 1% of Ah capacity at 14.8V, or stops dropping and stabilizes, you can then boost the voltage to 15.5V - 16V depending upon battery temp...

The opening question was about T-105's which are nominal 6V batteries, so is it correct that the voltages here should all be halved?

[daletournier]

Originally Posted by john61ct

Yes, standard stateside is .05C discharge current, the 20-hour rate.

> 130Ah USBattery, 3.8A load for the test -very typical for my fridge - battery went down to 9.5V at end of test

You may well have lost a fair number of cycle's lifetime. Better to put an LVD + alarm in if you're going to walk away.

You don't even want the batt to sit at 10.5V any longer than necessary, get it recharging immediately after hitting that 10.5 point.

> This puts the battery after discharge at about 35% SOC.

Compared to what? What gives you that idea? 10.5V at a low discharge rate is functionally **zero** SoC.

The whole point of the test for SoH is to determine the *actual* AH capacity; if that is 70-75% of rated AH, the batt is scrap (industry spec is 80%, but non-bluwater consumers can push past that, a bit.

> My BM always says battery reaches 100% ..... I say "bull%^&"!! even with aggressive parameters

100% SoC is when trailing current at Absorb V falls to endAmps spec, usually ~.005C

Never rely on an AH counter for that, it is **your** job to tell it when charge is finished, reset it at 100% Full frequently to keep it accurate. Ideally every cycle.

> My main question, when people refer to 'should not discharge below 12.2V; i.e.50% SOC', that surely is a resting voltage level. So how, when afloat, do you judge 12.2V? In my case the 'under load' V would be about 0.3V lower, say 11.9V

You can/should never rely on voltage or SG for SoC while cycling.

If your BM is properly reset and calibrated, the actual AH capacity kept updated as that declines, you just stop discharging when it reads 45-50% down.

So, if your **used-to-be** 130AH batt is now actually 90AH, you only have 45AH usable to work with at 50%.

And your batt is at end of life, in need of replacement before heading out for any extended cruising.

No not correct as the batteries are wired in series giving 12v.

BTW a new bank is great, at dawn this morning voltage was 12.6v[emoji3] ,thats with fridge etc running all night.

Originally Posted by robinco

The opening question was about T-105's which are nominal 6V batteries, so is it correct that the voltages here should all be halved?

[john61ct]

Originally Posted by robinco

The opening question was about T-105's which are nominal 6V batteries, so is it correct that the voltages here should all be halved?

Once a pair of 6V batts is series'd, it **is** a 12V bank and in use is treated as a single batt.

It is possible to break them up and treat them as 6V units, but rarely is that useful in practice.

[TheThunderbird]

Check the Trojan datasheet.

By heart, they require 14,7V charging, and 12,3V stands for 0% charge (zero).

So, at 12,05V they were not underchanged, but depleted (not knocked down, fortunately, as to MS's recommendations)

[john61ct]

Now irrelevant, ignore

[daletournier]

Originally Posted by john61ct

?

I was responding to davenz' Q's, as should be clear by my quoting.

And everything I wrote applies to 12V whether 2V x6, 3V x4, 6V x2 or single 12V batts.

Or any number of paralleled 12V strings for that matter.

If you want to take issue with a specific point, please quote it for clarity.

Hi John, accidentally quoted you, not sure how I did that, I think I'm more dangerous with IT stuff than batteries [emoji3]