Trojan batts , Chargeing them ?

[careka]

putting in 4 x L16G-AC 6 volts into the boat.
and data do say 14,8 Volt, and 13.2 volt
But not for how many Hrs, on each step.

What do you use ? settings on your charger.

[FlyingCloud1937]

14.8 is the voltage set point that the Charger/Regulator Drops to Constant voltage mode, from constant current mode.

This means that the charger/regulator puts as much current into the bats as they will accept, until the bulk voltage set point is achieved for the prescribed amount of time , the smart regulator then ramps into constant voltage mode.

In constant Voltage Mode, the charger/regulator ramps down current to maintain constant voltage at the battery. Ideally 14.6 volts until the charge current drops to a preset current. = Float charge

At this point Float Charge voltage is set to the self-discharge current plus loads.

A smart Charger is not a smart Charger unless it is temp compensated.

Temp compensation is what makes a smart charger, smart.

This means it has a temp sensor hard wired into the logic, and then the Smart Charger can adjust voltage and current to maintain battery at proper charge Voltage/Current/Temp Compensated for all of the stages.

Newer Smart Charger/Regulators have a 4 stage, called battery saver mode. This mode stops float charging until the battery reaches a voltage drop in excess of it's regular self discharge voltage. this means it will hold the battery at it's float voltage for a prescribed amount of time.

At which point the charger will shut down any voltage source until the battery reaches a prescribed voltage, then will ramp into absorption then back to float voltage.

This allows the battery to rest while on float, it saves water, and stops the plates from growing.

The best of these newer style battery saver Charge/Regulators will also act as power supplies.

What this means is the the Charger/Regulator will act as DC source when a load comes on, and power the load from the power source, instead of from the batteries.

Lloyd

Originally Posted by careka

putting in 4 x L16G-AC 6 volts into the boat.
and data do say 14,8 Volt, and 13.2 volt
But not for how many Hrs, on each step.

What do you use ? settings on your charger.

[careka]

I just got my new batts, and i now se that Trojan has a new web page out, and mine are not on the list anymore. did send them a mail, that they need to put out info of older batts also.
Trojan Battery Company | Renewable Energy

[FlyingCloud1937]

Or try TROJAN BATTERY CO.

Trojan Battery and Trojan Battery RE, are the same company.

Just that the RE Batteries have a lower SPG, and paste.

The lower SPG helps the bats last longer in a partial State of Charge. It is evidenced by the 7 year limited Warranty for RE.

As opposed to the 3 year limited warranty of the commercial bats.

Lloyd

Originally Posted by careka

I just got my new batts, and i now se that Trojan has a new web page out, and mine are not on the list anymore. did send them a mail, that they need to put out info of older batts also.
Trojan Battery Company | Renewable Energy

[sailinglegend]

Originally Posted by FlyingCloud1937

...In constant Voltage Mode, the charger/regulator ramps down current to maintain constant voltage at the battery. Ideally 14.6 volts until the charge current drops to a preset current. = Float charge...

I'm sorry FlyingCloud but think this is slightly misleading if not inaccurate. I know we sometimes have to simplify explanations here - this whole subject of charging needs a book on its own!

A smart charger in constant voltage/absorption mode of 14.6v is effectively limiting the output voltage to that value, but it is the battery that is limiting the current it can take from the charger. The more charged it gets the less current it can accept.

The problem is also that the charger can't work properly by dropping down to a Float voltage when the current reaches a pre-set value because it doesn't know what is happening to the current that it is supplying. Half could be going into the battery and half to boat loads, so the pre-set low current value may never be reached, and the battery overcharged. Chargers are designed to charge batteries and not overcharge them, so what most chargers do is drop to a Float voltage of say 13.6v after a set time, say 2-3 hours. This is highly unsatisfactory, as a large service bank may be nowhere near charged after say 2 hours. If the charger had a shunt to measure current into the battery that we would make it a really Smart Charger! There are a couple of expensive Solar controllers that do this.

A Smart charger/regulator must be adjusted to suit the battery type and voltages, and to match the size of the service bank, so the time at the absorption voltage should be set to a higher value so that when it does drop to Float it is maybe at 95% SoC. At Float voltages this extra 5% can still take a long time to charge as the batteries accept less and less current.

Battery voltage sensing and, yes temperature compensation, are also essential - especially if boat designers are dumb enough to put battery boxes in engine compartments.

The problem with Smart chargers is I fear that there are many end users who are not Smart enough to be able to set them properly. This is a harsh thing to say about some of my fellow sailors, but I have seen it so many times amongst friends that you have tried to help. Did you make those changes I suggested - no "It seems to work OK as it is"!!!!!!!!!!!!! So how long did your last set of batteries last then .....?

[noelex 77]

The time at the higher voltage is called the absorption time. Most regulators/chargers set this between 1-3 hours. The good news is that the exact time is not super critical. The bad news is that the time is only adjustable for some models.
Ideally the charger/regulator should drop to the lower voltage when the current entering the battery is in the order of 1-2% (4-8A for a 400 AHr battery bank) and the battery voltage is at the higher voltage.

You can monitor the current entering the battery and set the time so that in a normal cycle the voltage drops down from the higher voltage (14.8v) to the lower voltage (13.2v) when the 1-2% criterion is met.

Some chargers assume that the charge current is the same as the current entering the battery and use this as criterion instead of, or as well as time. This is incorrect if there is any load on the battery. Very advanced chargers/regulators monitor the current entering the battery, but this is rare.

My advice would be to choose an absorption time of say 1.5 hours. Monitor the current entering the battery at the end of the 1.5 hours, over a few cycles. If the current is less than 1.5% at this stage shorten the time, if it is more lengthen the time.

The lower float voltage (13.2v) can be maintained indefinitely.

As others have said temperature compensation is important, particularly for the higher voltage point. If your charger does not have a temperature probe the voltage can be manually adjusted for the different seasons. Also check the battery specifications if an occasional equalisation voltage is recommended.

[sailorboy1]

Originally Posted by noelex 77

My advice would be to choose an absorption time of say 1.5 hours. Monitor the current entering the battery at the end of the 1.5 hours, over a few cycles. If the current is less than 1.5% at this stage shorten the time, if it is more lengthen the time.

and if you have to add water to the batteries a lot, it is time to shorten the absorption time

[careka]

I have a Victron multi 12/2000/80-30 (also new), and can adjust nearly everything.
That why i like to se what you recommend.
Thanks. for al input.

[Zil]

This guy has some strong opinions about charging batteries.
HandyBob's Blog « Making off grid RV electrical systems work

[neilpride]

Haa Trojan, i change my set of 6 yesterday, actually they last for the past of 8 years , yes 8 years , some people dont believe me , still reading 12,20 v at night with just some cabin lights on, the trick for me is to keep the batteries topped with a mixture of acid and water always , trojans like hig rate of charge but not for so long or the batteries loose water , i have my balmar set to Gel batteries , the bulk time is short, the absortion time is short to, and the floating mode is long, and i do a Equalize job every month, at 16 volts for 3 or 4 hours to desulfate the plates , if you need to top off the batteries often, dont use destilate water to much, buy a mixture of sulf acid in bottles, in a marina let your solar panels do the job by day , and if you need it, charge by night with the batterie charger, dont keep the batterie charger 24/7 without check the water level or you risk a set of toasted Trojans, wonderfull batteries,,,,,

[sailinglegend]

Originally Posted by neilpride

...I change my set of 6 yesterday, actually they last for the past of 8 years , yes 8 years ...

With such confusing and bad advice I'm surprised they have lasted 8 years!!!!!

1. Don't add acid to batteries.
2. Trojan usually recommend a slow charge not a "High rate of charge".
3. Why set to Gel. Always set to the manufacturers recommended voltage. Gel would be 14.1 volts when the Trojan's need 14.8v.
4. The Absorption time should be set to match the size of the bank. A large bank will need a longer time so that when it drops to Float the batteries are close to fully charged. This is the probably the only and most important change you need to make from the default values.

[mitiempo]

Neilpride

Also equalizing should not be necessary on a monthly basis.

[careka]

Originally Posted by sailinglegend

4. The Absorption time should be set to match the size of the bank. A large bank will need a longer time so that when it drops to Float the batteries are close to fully charged. This is the probably the only and most important change you need to make from the default values.

I have 4 x L16G-AC 390amp 6 volt = total of 780amp 12volt
How many hrs on Absorption (14,8) ?
and then to 13.2 bulk, or 13.3 Bulk and 13.2V float.

[sailinglegend]

Originally Posted by careka

I have 4 x L16G-AC 390amp 6 volt = total of 780amp 12volt
How many hrs on Absorption (14,8)?....

The only thing you need to chane from the default is the absorption time. Bulk charging happens first by itself - depending on the charging current and the amount the bats are discharged. Set the absorption Bulk/Absorption voltage to 14.8v and then by trial and error change the absorption time until you get to about 95% charged when the charger first drops to Float. This should happen when the current going into the batteries is about 1-2% of the battery capacity at about 14.6 volts. As soon as it drops to float @ 13.2 you have to force the charger back to Absorption by turning it on and off to see what the charging current is at the absorption voltage. You'll need a Digital Ammeter or a Battery Monitor. Search this forum for much more information on Battery Monitors and their problems, Float and the "Charging Gotcha".

[careka]

i have Victron 602S Batt monitor, and Digital ammeter, voltmeter. ++