6vdc Trojan T105 (225ah) Equalization

[rgleason]

John,


I am sorry, I can't find the link to this statement, I believe it was in a comments section.

Originally Posted by rgleason Better [URL]Need the amperage to get the acid up to temperature of 105 to desulfate the battery. 2 amps won't do it, and I think 5 amps might not be enough.

Is it true? -- I have no idea.


Anyway I am now stuck on figuring out how many amps I need. If I try to equalize a single 6vdc battery I need 8.1volts (the battery has 225 amp hours capacity)

If I try to equalize (2) 6vdc in series I would need 16.20 volts with 225 amphours capacity.


I know my 10 amp Guest Charger will charge two in series up to about 14.7 volts (it is self regulated/controled).

Ohms Law

Volts = I current (amps) X R resistance (ohms)
14.7v = 10 amps x ?
7.3 = 5 amps x ?


It looks to me like if I get a 5 amp variable charger it will work with a single 6vdc battery, but I will not be able to equalize two in series at 16.2v ?



--Is that about right?

[john61ct]

Originally Posted by rgleason

I am sorry, I can't find the link to this statement, I believe it was in a comments section.

I'm sure it was misinformation.

Even if a charge source "offered" say 200A, the actual current is set by the battery, and will be very low after Absorb V has been held until endAmps shows 100% Full has been reached.

[rgleason]

The MFJ-4230MV for $89.95 could also power a Ham unit. What would the down sides of getting that unit be?
5" W x 2 ½" H x 6" D, 3 lbs
It seems to be adjustable from 4-16 volts
(2)6vdc in series need 16.2 volts to equalize.
(1) 6vdc needs 8.1 volts to equalize.

13.6vdc at 25 amps (30 amp surge)


I don't know if 16 volts is enough when they are in series.

[rgleason]

John wrote:

Even if a charge source "offered" say 200A, the actual current is set by the battery, and will be very low after Absorb V has been held until endAmps shows 100% Full has been reached.

That is very helpful, so I should just get the one you suggested?


Tekpower TP3005T Variable Linear DC Power Supply, 0 - 30V @ 0 - 5A with Alligator Cable and Power Cord, Linear type

[rgleason]

Just make sure you don't leave a bad battery in your bank as you'll never be able to equalize properly plus it will slowly ruin the rest of the bank.

This is one of my concerns.

If it does not come back with equalization, (to what degree?) then I need to get a new one I guess. At what point should that be done? I am pretty certain this is not a completely black and white decision, but some guidance would be helpful.

[Don C L]

I must be missing something. There must be a thread on this too, but can you not just use the shore charger for a 6v and disconnect it after a full charge and then reconnect it and add water and check specific gravity until it peaks?
https://www.trojanbattery.com/tech-s...y-maintenance/
I believe the "testing" section may have what you need.

[john61ct]

Equalization requires a very specific V range higher than Absorb, applied after 100% Full.

The purpose is prevention of problems, not heroic resuscitation.

Originally Posted by rgleason

If it does not come back with equalization, (to what degree?) then I need to get a new one I guess. At what point should that be done? I am pretty certain this is not a completely black and white decision, but some guidance would be helpful.

A 20-hour load test, ideally compared to one run when new.

When capacity drops by 20-30%, batt is toast, usually the whole bank needs replacing at the same time, not a good idea to mix old with new.

[john61ct]

Originally Posted by rgleason

John wrote:

That is very helpful, so I should just get the one you suggested?


Tekpower TP3005T Variable Linear DC Power Supply, 0 - 30V @ 0 - 5A with Alligator Cable and Power Cord, Linear type

The wider range gives more flexibility.

I haven't used either, just giving "this type of PS" so do your research, google forums.

A couple known-good brands mentioned earlier.

[sstuller]

Doesn't Mainesail say batteries should be oriented athwartship so plates won't be exposed when heeling? In contrast golf cart batteries should be installed fore and aft for the same reason - driving up and down hills will not expose the plates.

[OceanPlanet]

You have 2 x 6V batteries in series. When batteries are in series, they cannot balance the voltage between them. Rather, the same current flows in & out of each one no matter what the SOC is of each individual battery.

It sounds like you were only monitoring the PACK voltage, not the voltage of each 6V. I'll bet you that they are out of balance...that is, one is at higher voltage than the other.

Note that any two batteries are never exactly the same capacity. Over time they drift off, and normal charging may not "equalize" them. They need to be periodically connected to each other in parallel (not in series) so that the voltage can even out between them. Ideally you would charge them up together using a 6V charger.

With new batteries this is especially important, as they could been at different voltages from the beginning, due to different age, storage time, etc. And, it's not uncommon for new batteries that are supposedly the same to actually have very different capacity. Or for one or more to be simply a dud. It happens...

Some battery monitors (for instance a Victron BMC702 or 712) have the option to monitor a 2nd battery voltage. Typically this is used to monitor a starting battery, however it can also be used to "center tap" a series connected bank to see the voltage of half of the series banks. Ideally this voltage should exactly half of the pack voltage. If not, then they are out of balance and you could be seriously overcharging one half and undercharging the other..

[Maine Sail]

What Bruce just said is excellent advice. I see this all too frequently in series banks when they're not properly commissioned..

As for EQing a 10A x 30V an adjustable bench top power supply is short money these days...

[rgleason]

Yes, Bruce I was just monitoring the pack voltage, and they are out of balence. Also the individual cells are out of balance in both batteries. I need to charge them separately to 100% SOC and then equalize them sepaately (I believe). My 12vdc Guest 10amp, 3-step charger is not the right tool for this because it is 12vdc, only 3 steps (bulk, acceptance, float) and does not have controls to do equalization.

Two years ago I picked the Trojan T-105 because they were good deep cycle golf cart batteries that I could fit into my standard battery case and I got 225ah, but perhaps the 6v aspect complicates things too much, I can't find 6v chargers so I've been charging them in series both in the boat and with the Guest.

What charging and equalization tools should I be using?
I see here that Mainesail is using a big Mastech for "Prestorage Equalization" and it looks like he is doing a single battery in a 2 battery parallel setup.

Don,
Trojan Battery Maintenance Is pretty much what I have been reading, and I believe I saw that suggestion about disconnecting the charger and reconnecting, but the voltage does not go up to the required equalization voltage (for 6vdc =8.1v, for 12vdc=16.2v). At least with my Guest charger when connected in series to the 12vc "pack" it just goes up to 14.7v which is not adequate.

Trojan on "Charger Selection"

There are many types of chargers available today. They are usually rated by their start rate, the rate in amperes that the charger will supply at the beginning of the charge cycle. When selecting a charger, the charge rate should be between 10% and 13% of the battery’s 20-hour AH capacity. For example, a battery with a 20-hour capacity rating of 225 AH will use a charger rated between approximately 23 and 30 amps (for multiple battery charging use the AH rating of the entire bank). Chargers with lower ratings can be used but the charging time will be increased.
Trojan recommends using a 3-stage charger. Also called “automatic”, “smart” or “IEI” chargers, which prolong battery life with their programmed charging profile. These chargers usually have three distinct charging stages: bulk, acceptance, and float.

For 225ah, they suggest 22.5 amps to 29 amps, but they state chargers with smaller startup amps will just take longer. The Guest 3 stage, 10amp, 12v should be fine then, but it is 12v! - also that does not do Equalization of a single battery. -and since my batteries appear to be at different SOC, I need to fully charge at least one of the 6vdc batteries separately. What would I use to do that? Is there a 6vdc/12vdc smart charger with 3 stages and "Equalization" and the ability to control voltage to 8.1 and 16.2?

[rgleason]

Originally Posted by Maine Sail

What Bruce just said is excellent advice. I see this all too frequently in series banks when they're not properly commissioned..

As for EQing a 10A x 30V an adjustable bench top power supply is short money these days...

Wow, I have some pros helping. Thank you.
Ok so I get a separate tool for Equalizing that is 10A x 30V adjustable.
How do I fully charge each battery separately? Use the same tool following Trojan Tables for charging? My Guest is for 12v.

[rgleason]

Mastech website
Shows that it should be a switching power supply for "Battery charging and equalization for Lithium Ion batteries, marine and vehicle batteries"

Mastech Regulated Variable Switching DC Power Supply 30V 10A HY3010E
Looks almost exactly like the one Mainesail shows in the picturer. It is $139.

[rgleason]

John linked to (or suggested a similar 10a)

Tekpower TP3005T Variable Linear DC Power Supply, 0 - 30V @ 0 - 5A with Alligator Cable and Power Cord, Linear type $80

This is a linear type, but I guess it would also work. It is just a 5amp power supply, which may be a little under what is I need. (unconfirmed).

If I were to get a similar adjustable 10a it would be a switching power supply.

TekPower TP3010E DC Adjustable Switching Power Supply 30V 10A Digital Display $89
Says: output continuously adjustable at 0-30V DC and 0-10A. Despite some bad reviews, it does have 4 stars and some glowing but realistic reports from some experienced users
(Tim Jan 11 2015)

Some users noted a problem with the LCD display turning off. I contacted KaitoUSA and they were very helpful. After discussion with their engineers, I was able to fix the problem by simply removing 4 small components ( R21, R22, C8, C11) from the front-panel PCB. KaitoUSA is now aware of the problem and I believe all shipping units should come with the problem fixed. The LCD no longer turns off and the unit works great!

As for regulation and ripple, my measurements indicate that the unit is more or less operating within its paper specifications. I would not expect it to perform as well as a linear supply, but is in line with most switching supplies of this class. This supply will also be a good complement to a precision linear supply.

To conclude, for users who frequently need a high power yet portable supply for driving heavy loads such as battery charging for RC hobbyists (e.g. charging batteries out in-location), powering fans / motors / bulbs etc, I would recommend this unit! Ultimately it's a nice little supply which has found a place on my electronics workbench.

Haitronic DC 30V 10A adjustable switching DC Power Supply, from input AC 110V to precise variable DC 0~30V @ 0~10A output, 3 Digital Display
This one has 5 stars but only 2 reviews.

Mastech HY 3010E is unavailable on Amazon and it will be $170 through Mastech