What kind of charge controller was installed in 2013?

[Bailey'sMom]

Hi all

My TM is still tucked away in storage right now, but I am researching new batteries. Been looking at old threads. Thinking about buying AGMs to replace my current 2 6v golf cart batteries.

One of the threads mentioned needing an MPPT controller if you are using AGM batteries. How do I know which charge controller I have? I believe mine was factory installed with my 80W solar panel.

I won’t be able to pop up my trailer for another 6 weeks or so.

Hoping some one can tell me what was likely installed in a 2010 model. (Not 2013 as stated in thread name) Also if you can attach a pic of yours that would be great so I know for sure what a charge controller looks like. I am assuming it’s the thing that tells me the state of charge of my batteries?

(I know my total ignorance on this topic is shing thru, that’s why I’m asking)

Thanks in advance.

[Bill]

How many 80 watt panels do you have installed?

Bill

[Craigrrr]

Just a note, you do not need an MPPT controller for agm batteries a PWM will work , I have been using agm and pwm controller last 3 years no problems

[tentcamper]

+2

[Craigrrr]

Here is my current pwm charge controller I am using with AGM batteries and 2-100 watt panels

https://smile.amazon.com/gp/product/B00O8RGCCQ/ref=oh_aui_detailpage_o06_s00?ie=UTF8&psc=1

[Bailey'sMom]

How many 80 watt panels do you have installed?

Bill

Just one. It was the standard factory option.

[Bailey'sMom]

What brand are you using, where did you buy them, and approx how much did they cost?

[Kidkraz]

Sara, in my rig I have the WF-8955AN World Frindship converter. I also have the 80 single solar panel set up.

[Craigrrr]

What brand are you using, where did you buy them, and approx how much did they cost?

I bought them from Amazon

one I paid 164 the other was only 149

https://smile.amazon.com/gp/product/B00S1RT58C/ref=oh_aui_detailpage_o07_s00?ie=UTF8&psc=1

[rickst29]

Gel cells require reduced Charging Voltages, but AGM does not need a different profile than "regular" flooded cell batteries.
The two questions which might justify a new, MPPT-type charge controller are:

#1 (Most important): Are you failing to charge up the batteries to 85-90% maximum SOC with the Solar setup you now have?If you can fully charge the batteries now, then buying more panels (or a "better" controller) is money wasted on extra "charging power" which you will never need to use.

#2 (Second most important): Do you anticipate a need for more than 250 Watts of "maximum panel power", because you will be camping in non-optimal conditions, or because you consume a lot of power during the daytime?

MPPT controllers improve the efficiency of all the panels by about 20-25%. But they typically cost at least as much as adding another panel. If you have (or will have) less than 200W (nominal "max") on the roof, then your money is almost certainly better spent by simply adding another panel. When you cross over from 200W "max" to 300W "max", then the additional power provided by MPPT could be cost effective.

But when you consider a "need" to upgrade above 300W nominal "max" of all your panels together, than upgrading to MPPT will buy more "power per dollar-spent" than you get by adding yet another panel into a PWM controller.
For example: A PWM controller, charging batteries at 14.4V, will connect and disconnect the Panels very rapidly to make the average Voltage from the Panels. But a typical "100W Panel" will try to deliver those 100W as 17.9 Volts * 5.59 Amps (BTW, that is a genuine and typical pair of numbers.) A PWM controller will refuse to take in power which the panels could have provided at "excessive", accepting only the operating current (5.59A) at the controller-limited "Average Voltage Desired" (14.4V, or perhaps as little as 14.2V. We'll use 14.4V, that's the best case for PWM.) 14.4V * 5.59 = 80W, the other 20W are never delivered to the battery. A good MPPT controller would convert that 20W into more current at the lower Voltage, minus about 3% efficiency loss, yielding about 97W.

With just one panel, those 17W are insignificant (in comparison to the price of an MPPT controller). But with 4 panels, the PWM-wasted power is approaching 80W. That's nearly an entire panel of unused energy. In different operating modes, the charging Voltage might be only 14.2V (with max current allowed at that Voltage). In that mode, PWM loses another 11W on each panel, and MPPT has delivered about 120W more energy into the batteries (and appliances) than the PWM could do -that's more than an entire panel, but only when the configuration is large.

Unless you will need to upgrade the "80W" panel into more than "200W" on the roof, stay with PWM.

[Bailey'sMom]

Thanks Rick. Very detailed info.

I only have the one 80W panel and have no plans to,add more. So it sounds like I will,have no,need to upgrade my controller.

My batteries do fully recharge with the solar panel, but doesn’t hold the charge very long anymore. I don’t know exact age of batteries because it was not marked on either one. Could easily be the original batteries.

I purchased in 2013 and this will be my sixth summer with the trailer. But if they are original then batteries could be eleven yrs old.

I don’t really use much power but especially last yr I noticed that batteries would run down more quickly than in the past if I used the fan a lot.

[rickst29]

Your batteries are (almost definitely) past EOL - if you replace them, first, you might find that nothing else is required.

But the batteries need to be sufficient, without wasting money on storage you don't need. How much power does that fan actually use? The original Fantastic in my own TM had only one speed (using about 4A continuous), and running for more than just a few hours could add up pretty fast.

If you used the same fan for 8 hours, it would consume 32Ah - and your batteries, when brand new, were probably only good for 70Ah total storage each. (Batteries were a dealer-selected, dealer-installed add-on. So TM dealers didn't go super-good, unless specifically requested and paid to do so by the customer.)

But two factors would cut into using that, even when the batteries were new:


You shouldn't drag most batteries below about 50% SOC ("State of Charge"). They can be driven lower, but it hurts the battery lifespan (by dramatically reducing the number of future "charge" operations which can be completed effectively.)
The Solar Charge Controller which you've got can't get them much above 80% State of Charge ("SOC"). It doesn't have smart enough logic, and the last 10% usually takes many hours (because it's mostly done within low-power "Float" mode). At home, Even my ultra-fancy CTEK battery tender (7 stage) needs about 3 full days to reach "stage 7 operation" on my own batteries after a trip. My batteries are a lot newer than yours, and they've never been abused.

So, instead of getting 70Ah from, each battery, you need to leave about 35Ah unused in each one (to prevent increased battery damage. Then to make matters worse, that inability to reach the last 15-20% during a boondock cuts your available power a lot more: 65-70% of the "nominal" Ah on the label either can't or shouldn't be used on a regular basis. (Forklift battieris are built differently, and can be taken below 50% - but they cost a fortune, and don't come in our sizes.)
Figure out your loading first - how much power (AH at 12V) do you need to consume? Multiply that number by 3, to account for the 65-70% "unavailable" total. Then divide by the number of batteries you need to buy (arriving at battery size), or divide by the size of batteries you intend to buy (arriving at the number of batteries you will need.)

Your solar charging requirement is the power you will consume - excluding the two "battery factor" adjustments, but maybe increased for partly-cloudy days and off-season camping (shorter days, worse angles for sunlight). If you will use PWM, you also need to add back any PWM power losses to yield the total panel "nominal power" size, per my last post.

1: power "requirement".
2. Battery configuration, after battery "factors" added to #1.
3. Buy batteries.
4. Solar Requirement, after adding Solar "factors" to #1
5. If insufficient, buy more or better Solar stuff.