Looking for Charger for Trojan T105s

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wradar

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Sep 12, 2015
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Hello, all! I have two T105s set up in series on our camper trailer. Trojan's specs state that it needs to be charged at:
    Absorption 14.8V
    Float 13.2V
    Equalize 15.5V

The trailer's existing WFCO WF8955 converter only charges at:
    Absorption 13.6V
    Float 13.2V
    Does not seem to have an equalize option (though it does bulk at 14.4V)

I've read many forms that discuss various chargers and converter/chargers, but none of them seem to get to the Trojan's spec'd 14.8V absorption recommendation. The often-cited PD9260CV only boasts 13.6V "normal" (which I presume is their word for "absorption"). Another popular option, the Iota DLS-45 with IQ4 only has a 14.2V absorption rate.

The only charger I've seen that can actually get close to the recommended 14.8V is the Magnum products which get to an absorption of 14.6V.

Is there a charger or converter that can actually get to an absorption of 14.8V? If not, what voltage should one shoot for if using the T105s? I don't think my WFCO converter is close enough, but correct me if I'm wrong.

Thanks!
-Will
 
The Magnum is one of the most highly thought of chargers here on the forum. Stand by, one of our resident electrical guru's will chime in shortly.
 
This is a question I have thought about often. I would guess that very few RVs with deep cycle batteries have a charger that will charge them properly.  I have solar on my RV, and I have a Morningstar Tristar 45 amp MPPT controller which will charge deep cycle batteries properly.
 
I think you missed the full WFCO spec. It is a 3-stage charger and provides 14.4v in bulk mode, 13.6 in absorption mode, and 13.2v float.  The Trojan T105 spec doesn't distinguish between absorption and bulk modes, probably because it does not assume that three-stage charging is available. A typical basic charger would produce around 14v for primary charging and then shift to a float or trickle mode.

Equalizing is not a normal charge mode and few people ever actually do it even if they have the capability. It isn't even needed in most cases - it is primarily used to help recover a battery that has been undercharged too long.

In short, your WFCO 8955 will do a good job with the T105's. Save your money for something else.

 
Maybe a description of the difference between absorption and bulk charging modes would help. Looks like there might be a misunderstanding in the nomenclature.

Gary is correct pertaining to the equalize mode of charging. Assuming correct care and maintenance of the batteries, you will be just fine with your current set up. I actually believe it's more of a marketing ploy. 
 
denmarc said:
Maybe a description of the difference between absorption and bulk charging modes would help. Looks like there might be a misunderstanding in the nomenclature.

Gary is correct pertaining to the equalize mode of charging. Assuming correct care and maintenance of the batteries, you will be just fine with your current set up. I actually believe it's more of a marketing ploy.

I am not quite sure what you believe is a marketing ploy.  Would you explain?
Thanks!
 
I agree with Gary. My PD 9260 instruction manual says not to use the equalizing function even though it is available on the dongle. The only time I used it was for an initial charge when I purchased new GC-2 batteries.
 
Paul & Ann said:
I am not quite sure what you believe is a marketing ploy.  Would you explain?
Thanks!

No problem.
The "equalizing" aspect of it.
In my minds eye, if one takes care of their batteries regardless of individual batteries in the bank, equalizing wouldn't be necessary. As Gary mentioned, most people don't ever use the equalize mode of their charger, even if it's available. Some don't even know what that mode is used for!

But if a manufacturer advertises that on the box of said product...
Well then, that must be one heck of a product! Gotta buy it!

Very generally explained, mind you. I hope it made sense. My point being I really believe that if you take care of yours batteries, equalization doesn't even come into the picture. As long as the charger is capable of keeping the bank charged using the correct stages of charging without boiling. They are depleted and charged as one.

Does that help in answering your question?
   
 
Although, I have never equalized my batteries, in the winter they see 15.1-15.3 volts on a regular basis with my solar controller set at 14.7 temperature adjusted.
 
The main reason to equalize batteries is to prevent stratification of the electrolyte, where the acid and water separate into discrete layers in each cell.  An equalizing charge makes the batteries outgass and the bubbles passing through the electrolyte mix everything back up.

Stratification is a problem with stationary batteries like in a stick and brick solar installation - in RV use normal road motion mixes the electrolyte every time you move the rig.
 
Gary RV Roamer said:
I think you missed the full WFCO spec. It is a 3-stage charger and provides 14.4v in bulk mode, 13.6 in absorption mode, and 13.2v float.  The Trojan T105 spec doesn't distinguish between absorption and bulk modes, probably because it does not assume that three-stage charging is available. A typical basic charger would produce around 14v for primary charging and then shift to a float or trickle mode.

Equalizing is not a normal charge mode and few people ever actually do it even if they have the capability. It isn't even needed in most cases - it is primarily used to help recover a battery that has been undercharged too long.

In short, your WFCO 8955 will do a good job with the T105's. Save your money for something else.

I agree, the existing converter will be fine.  If you are worried about the sulfation, connect a desulfator.  I have a 48V unit on my RXV cart bank and keep this 12V unit connected to various batteries with periodic charging cycles.  After moving to AGM on our SRX, I attached the 12V unit to our old 12V group 27 flooded battery that came out of the trailer, it brought the battery back to new condition.  Just another option.
 

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So getting past equalization.  I wonder what the difference is in battery life, and charge available between only charging T-105s to 14.4 volts and the recommended 14.8 volts?
 
Thanks for the great info, everyone. So, unless anyone has information to the contrary, it sounds like I can keep the WFCO unit and not have any problems.

That being said, Paul & Ann have essentially hit the crux of my inquiry. Will charging below the manufacturer's recommendation noticeably impact the battery's life or performance?
 
Bulk/Absorption charging:
Bulk is high speed (lots of amps) with regulated voltage.
Absorption is lower speed (very few amps) regulated... This is the last 10% of the charge.

Many "3-stage" chargers limit both voltage and current, but do NOT change the limits as the SOC rises.. They say "3-stage"
and may even indicate 3 different stages on their display (if they have one)

But in fact what happens is as the State of Charge rises, the charging current provided by the converter naturally goes down and becomes "Absorption"..  What starts at 50 amps, as charging happens, becomes 40,30,20,10,5 (Absorption level) zero,, at this point it switches to FLOAT mode.

Now: This may sound bad, but for Motor Homes and Trailers it is better than a true 3 stage.

True 3 stage the current is limited in BULK mode, but this means the voltage keeps climbing,, And by the time it switches to ABSORPTION (where current is regulated,,, by lowering the output voltage of the converter) you have damage to your electronic devices from the excessive voltage  But by limiting both voltage (to protect the electronics) and the current (to protect the converter) in Bulk and Absorption modes... No damage happens.
 
But in fact what happens is as the State of Charge rises, the charging current provided by the converter naturally goes down and becomes "Absorption"..  What starts at 50 amps, as charging happens, becomes 40,30,20,10,5 (Absorption level) zero,, at this point it switches to FLOAT mode.

That seems to me to be a definition for a single stage charger and the opposite of what a 3-stage unit does. If the charger merely lets the battery control the amp rate through its internal resistance, then there are no "stages". Or if it has a separate "float" mode, then maybe it's a 2-stage charger.  Common automotive battery chargers do it in the fashion you described, but I don't think any unit described as "3 stage" does that. It would be blatantly false advertising if they did.

True 3 stage the current is limited in BULK mode, but this means the voltage keeps climbing

A typo, John?  The only limit on amps in bulk mode is the max output of the charger and the amount the batteries are willing to accept. The charger does not limit amps in that mode.

This article is simple but instructive:
https://www.batterystuff.com/blog/3-stages-of-smart-chargers.html
 
John From Detroit said:
True 3 stage the current is limited in BULK mode, but this means the voltage keeps climbing,, And by the time it switches to ABSORPTION (where current is regulated,,, by lowering the output voltage of the converter) you have damage to your electronic devices from the excessive voltage  But by limiting both voltage (to protect the electronics) and the current (to protect the converter) in Bulk and Absorption modes... No damage happens.

Not true on the Inverter/Chargers I've used. My current Magnum 2880MMS switches from Bulk to Absorption when it reaching aborption voltage which in turn is set in the battery profile by battery type. For my Lifeline batteries this is set at 14.5, but it is temperature adjusted.

ken
 
I'm just not seeing a problem to address with this.  If one wished to spend on an advanced charging system then reaching the rates can be obtained.  However, is this really worth it or necessary? Only your wallet can decide that question.  Equalization is to boil-off the sulfation, if that's a concern, again, put a desulfator on the system.  If not, the WFCO you have will provide fully charged batteries, enjoy the charge!  Here is the Trojan spec sheet.  My personal experience is with the T-1260 plus batteries.  Keep them from sulfating and you have healthy batteries.  Well, the upload limit is not allowing the full data sheet .pdf, here is a capture.
 

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Again, thanks, everyone. I'm good with keeping the WFCO, and don't really care that it doesn't equalize. I was just curious if it's inability to get all the way up to 14.8V for bulk/absorption would at all be an issue. It seems that the answer is "no." Great news!  ;D

Again, thanks, everyone for all of the feedback!

Now, on to the next project: solar!  8)
 
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