Battery and Solar woes

[Qwazert]

Long read, so grab a coffee...
Rockwood Mini-Lite 2306.
We’ve had this generic 100W flexible solar panel which has served us well for several years now. I hate drilling holes in the roof of my RV to pass wires through, so we simply toss the panel onto the roof when we arrive, and make connections to the controller and batteries. When not in use, the panel travels inside the RV between two mattresses, to keep it safe.
I coupled it with a 10Amp PWM controller that I had purchased from a different solar vendor a few years prior. This controller is adaptable for flooded or AGM batteries, but was set for flooded, as that is what we’ve always used. The controller has minimal user-interface (other than setting the battery type) and the only display you have is two green LED’s to indicate proper connection, and when the batteries are “fully charged” it will blink a green light to show “full”. As I mentioned, this setup has served us well for the past several years.
Last year, I needed to replace the batteries in the RV as they were over 6 years old and one of the terminals was starting to show deposits, meaning that gas was leaking through somewhere. I replaced them with a pair of Trojan T-105’s.
We do a mix of dry and full-hookup camping over the summer months, so either the solar panel or the on-board charger is keeping the batteries at the ready...according to the LED display on the controller or the one inside the RV.
Things started acting up on this last trip; after a couple of days of sunny skies, we had a few days of rain which meant the batteries wouldn’t get full power from the panel, but enough to keep the interior indicator showing 100%, and the green LED on the controller blinking. As soon as dusk fell, the indicator would show about 80% and would drop to 40% when running the water pump. This wasn’t normal, so I looked into the battery connections...definitely not perfect, but not bad enough to cause this. Cleaned them up but the results didn’t change. Luckily my buddy had a hygrometer, so I tested the individual cells...reading around 1230...only about 75% “fully charged” contrary to what my solar charge-controller was telling me.
The next few days gave us some more sun, so I monitored them carefully. According to the T-105 data sheet, the OCV of each battery when fully charged should be 6.37 yet even when I was able to achieve this reading through use of the solar panel...the hygrometer would still only indicate about 75 - 80 % charge. I use a high-end FLUKE multi-meter, in case there’s any concern about my tool-of-choice.
By contrast, my buddy also has the T-105 batteries and his OCV is around 6.9 and the hygrometer shows fully-charged.
When we arrived at the “full hookup” site the following week, the converter/charger in the RV went wild, as it struggled to charge the batteries. After about 4 hours with the fan running full blast, it finally quieted down and the batteries seemed to catch up and recuperate to full charge....or so I thought.
Checking them with the hygrometer again...only 80% charge even though the OCV was 6.6V now. By now, I’m starting to question whether this hygrometer is accurate, so my buddy takes it over to his rig and checks his batteries...100% charged.
At this point, I’m wondering if my converter/charger is defunct, so I pull out the manual and run through the troubleshooting guide. According to it, the output terminals should read 13.6 with the batteries disconnected...it only reads 13.2....half of which is 6.6...sound familiar?
I usually carry a spare car battery for Emergency use and even it shows between 1220 and 1230 on the hygrometer after being “charged” on the solar panel.
So it looks as if I have several issues at play here. One is the charger in the RV not putting out enough and the other being the charge controller from the solar panel also giving me bad intel.
I could use some advice/feedback....

[Gdetrailer]

Qwazert wrote:

I understand what you are saying and I appreciate your input, but there seems to be a misconception regarding my "setup".
At no time do I have the solar AND shore power working together...it's one or the other.

When dry-camping (or boondocking), we will use the solar panel to keep the batteries charged, or at least that's what we used to do before the gigantic battery upgrade. The stock batteries were installed by the dealer at the time of sale, so I imagine they weren't top-of-the-line types.

When dry camping, we don't use the inside shower...rarely use the furnace...only roll up the awning during high winds...basically, we turn on a light or two at night to find our way around. When getting ready for bed, we have battery-operated taplights at bedside. In other words, we put very little demand on our batteries, other than what the parasitic loads are. The fridge is a Dometic absorption-type, so it doesn't have a compressor.
When connected to shore power, the solar panel is stashed away and is not used...why would it?
Only when we are "full hook-up" do we run our AC or furnace...leave lights on indiscriminately, etc.
Might not be the way "most" people operate, but that's how we do it.

Furthermore, all of the disconnecting and removal was a one-time thing to verify if my batteries were salvageable...I don't do it every time.

In bold type is your problem.

100W solar panel "may" have worked OK, but adding MORE battery capacity, it no longer is able to keep up with the barebones basic draw downs plus any other additional optional draws.

Since you obviously are not using a gen daily to supplement and compensate for the load demand, you are constantly drawing your battery down further and further each day.

You buddy with same rig but with a 190W panel is obviously not having your issues which leads me to conclude your panel is not of sufficient wattage to not only keep up with demand but actually put a charge back into the T105s.

To do this, you NEED voltage and you NEED sufficient current, you have neither.

2A-4A for the very short window of solar charging isn't cutting it, you need 200W-300W to get it done. This is because the typical high point of solar charging is about a 5 hr window and that is on the longest day of the yr and when the sun is directly above your panel and you have zero clouds and you are not at a high northern latitude.

If your panel is not pointing directly at the sun and is angled, it will never be able to harvest the maximum rating.

That is why your buddies system is outperforming yours and hasn't killed his batteries.

You want to stop killing them, add MORE solar and/or use a generator at your campsite to pump energy back into your batteries.

[3_tons]

Well, admittedly I’m diagnosing from a distance, but from the info you’ve provided and using the principle of Occam’s Razor, it sounds to me like your Trojans may have suffered from a prolonged case of undercharge…Even though you can made a fair case for slight consumption, my sense is that (the other side of the equation…) the batteries have over a time sulfated (thus, of diminished capacity) due to an insufficient charge regime - equalization may restore them - Again, JMHO

3 tons

[Qwazert]

Gdetrailer wrote:

You need to consider "changing up" what you are doing.

You are working much harder than necessary by disconnecting, removing, moving, charging separate, then moving, reinstalling and rewiring them. It may have worked well for you for yrs, but there IS a better way that does not require all that work.

You do have a built in charger, although the one you listed is made by WFCO which is a multistage converter, it is somewhat less than ideal since there have been reports that it often does not go into bulk mode (14.4V) and gets hung in 13.6V mode. You reported the last two digits of the the model number which is 55.. That is the amperage the converter can supply.. Yep, you have a 55A CHARGER..

The trick is to see if the voltage at the battery terminals goes above 13.6V while on shore power, if it does then you are golden to let the converter do the work once you get home or while camping with a gen running.

The voltage is important, those small chargers you are using will not be able to provide 14.4V until the amps taper down significantly (like less than 1/2A).

One of the issues with WFCO converters is they monitor the battery voltage and the current being drawn and if the voltage is above a certain threshold and you have enough parasitic phantom current loads the bulk mode never gets tripped. This problem can often be resolved but that often requires removing all of the parasitic phantom loads plus upgrading the wire size from converter to the batteries..

Additionally with having solar feeding the batteries that may present more challenges to getting the WFCO to trigger bulk mode voltage.

You can save a lot of back breaking labor by considering more solar and perhaps replacing the WFCO converter with a Progressive Dynamics converter with Charge wizard.. PDs just work and is what I am using on my rig..

My batteries love the PD I have and thank me with 9+ yrs of service.. I abuse them pretty hard since the batteries must supply power 24/7 to my home fridge conversion.. I can run the fridge, furnace and some lights for 20hrs before recharging.. I have no solar at all.. If I added 300W of solar I could easily run off of the same batteries for a 3 day weekend and never have to run a generator.

I understand what you are saying and I appreciate your input, but there seems to be a misconception regarding my "setup".
At no time do I have the solar AND shore power working together...it's one or the other.
When dry-camping (or boondocking), we will use the solar panel to keep the batteries charged, or at least that's what we used to do before the gigantic battery upgrade. The stock batteries were installed by the dealer at the time of sale, so I imagine they weren't top-of-the-line types.
When dry camping, we don't use the inside shower...rarely use the furnace...only roll up the awning during high winds...basically, we turn on a light or two at night to find our way around. When getting ready for bed, we have battery-operated taplights at bedside. In other words, we put very little demand on our batteries, other than what the parasitic loads are. The fridge is a Dometic absorption-type, so it doesn't have a compressor.
When connected to shore power, the solar panel is stashed away and is not used...why would it?
Only when we are "full hook-up" do we run our AC or furnace...leave lights on indiscriminately, etc.
Might not be the way "most" people operate, but that's how we do it.

Furthermore, all of the disconnecting and removal was a one-time thing to verify if my batteries were salvageable...I don't do it every time.

[3_tons]

Since it seems that your batteries may be suffering due to a improper charge regime, if you have a such a bench top charger that puts out upper 14.9 to lower 15.x volts, you might consider putting a say 30-40 min or so cell-equalization charge on the T-105’s to help drive the sulphate from the plates and back into the chemical soup solution…(Be sure to loosen or remove caps…).

FWIW, I would agree that in your application the ‘single’ 100w panel is a toy - hopefully your batteries function can be restored…

3 tons

[Gdetrailer]

Qwazert wrote:

Gdetrailer wrote:

Both "chargers" you are using are toys, it will take weeks to months to fully charge those T105s and even then, I doubt they will be more than 98% charged..

Your "converter" in your RV should be capable of at a min of 35A which will speed charge your batteries compared to those pea shooters provided the converter is capable of switching to bulk charge mode of 14.4V.

You are safe to keep both T105s in series for 12V charging, there is no need to break them apart like you are doing unless the cells clearly show discrepancies in the specific gravity reading between the two batteries.

Nothing like doing things the hard way :S

This is the only way I've done it so far...in the past 15 years of using solar panels, this is the first time I've encountered any issues.
Nonetheless, I will keep these batteries on the chargers until the specific gravity reaches 1.277 (100% charged as indicated by the spec sheets for this battery), then I will return them to service.
Hopefully, I haven't caused irreversible damage by under-charging them.

You need to consider "changing up" what you are doing.

You are working much harder than necessary by disconnecting, removing, moving, charging separate, then moving, reinstalling and rewiring them. It may have worked well for you for yrs, but there IS a better way that does not require all that work.

You do have a built in charger, although the one you listed is made by WFCO which is a multistage converter, it is somewhat less than ideal since there have been reports that it often does not go into bulk mode (14.4V) and gets hung in 13.6V mode. You reported the last two digits of the the model number which is 55.. That is the amperage the converter can supply.. Yep, you have a 55A CHARGER..

The trick is to see if the voltage at the battery terminals goes above 13.6V while on shore power, if it does then you are golden to let the converter do the work once you get home or while camping with a gen running.

The voltage is important, those small chargers you are using will not be able to provide 14.4V until the amps taper down significantly (like less than 1/2A).

One of the issues with WFCO converters is they monitor the battery voltage and the current being drawn and if the voltage is above a certain threshold and you have enough parasitic phantom current loads the bulk mode never gets tripped. This problem can often be resolved but that often requires removing all of the parasitic phantom loads plus upgrading the wire size from converter to the batteries..

Additionally with having solar feeding the batteries that may present more challenges to getting the WFCO to trigger bulk mode voltage.

You can save a lot of back breaking labor by considering more solar and perhaps replacing the WFCO converter with a Progressive Dynamics converter with Charge wizard.. PDs just work and is what I am using on my rig..

My batteries love the PD I have and thank me with 9+ yrs of service.. I abuse them pretty hard since the batteries must supply power 24/7 to my home fridge conversion.. I can run the fridge, furnace and some lights for 20hrs before recharging.. I have no solar at all.. If I added 300W of solar I could easily run off of the same batteries for a 3 day weekend and never have to run a generator.

[Qwazert]

Gdetrailer wrote:

Both "chargers" you are using are toys, it will take weeks to months to fully charge those T105s and even then, I doubt they will be more than 98% charged..

Your "converter" in your RV should be capable of at a min of 35A which will speed charge your batteries compared to those pea shooters provided the converter is capable of switching to bulk charge mode of 14.4V.

You are safe to keep both T105s in series for 12V charging, there is no need to break them apart like you are doing unless the cells clearly show discrepancies in the specific gravity reading between the two batteries.

Nothing like doing things the hard way :S

This is the only way I've done it so far...in the past 15 years of using solar panels, this is the first time I've encountered any issues.
Nonetheless, I will keep these batteries on the chargers until the specific gravity reaches 1.277 (100% charged as indicated by the spec sheets for this battery), then I will return them to service.
Hopefully, I haven't caused irreversible damage by under-charging them.

[Qwazert]

3 tons wrote:
You didn’t mention the type (number of stages?) or brand of the onboard charger, but the 13.2v reading might have been during float (??)…If it’s a Progressive Dynamics, you can use their optional Charge Wizard dongle to kick the voltage up to Boost… Either way, in the real world (calc’s and other issues aside…) it’s difficult for me to see how a single 100w panel can up-charge two Trojans…Considering wiring losses and latitude, etc, at best I see the lone panel as more of a maintainer than a true charger - FWIW, old rule of thumb is 100w per 100a/h - from my own GC batt experience that would be the absolute very minimum - JMO

3 tons

The onboard charger/converter is a WF-8955PEC type.
This has definitely been a learning experience...my knowledge of solar charging is minimal, despite being a maintenance electrician for over 30 years.
I specialized in repairs of sterilizers, switchgear, ktichen equipment, fire alarm, etc....not in solar power.
Didn't realize that "upgrading" my batteries was going to have such an effect on things, or I would have stuck to the cheaper type that served us well for the past six years!

[Gdetrailer]

Qwazert wrote:
An update....

I took both T105's out of the RV this morning. One is on the Shumacher 6V 6A charger, the other on the NOCO Genius.
Shumacher showed about 4 amps of charge-rate at the beginning (about 2 hours ago) and has since fallen to below 2A.
SG reading is 1275 on all cells, so we seem to be making progress....cautiously optimistic so far.

I haven't taken any readings on the NOCO battery as it has a maximum 2A charge rate and is currently in "maintaining mode" with the green LED pulsing.
I will probably leave that one until this evening at the earliest.

As I overcome one problem, I start hypothesising about others....maybe I had "enough power" last year because the batteries were so new and we definitely had more sunny days than this year...it has been a dismal Spring and unimpressive Summer so far, in terms of hours of sunshine.

Both "chargers" you are using are toys, it will take weeks to months to fully charge those T105s and even then, I doubt they will be more than 98% charged..

Your "converter" in your RV should be capable of at a min of 35A which will speed charge your batteries compared to those pea shooters provided the converter is capable of switching to bulk charge mode of 14.4V.

You are safe to keep both T105s in series for 12V charging, there is no need to break them apart like you are doing unless the cells clearly show discrepancies in the specific gravity reading between the two batteries.

Nothing like doing things the hard way :S

[Gdetrailer]

Qwazert wrote:

Gdetrailer wrote:

2.2A-4.5A solar charge?

You are severely and chronically undercharging T105 batteries..

I think you are severely underestimating your energy usage and needs which contributes to killing your batteries in a hurry.. Properly maintained even with 50% DOD but promptly recharged those T105s should net you 9-11 yrs worth of service..

Typically with solar you get about 5 peak solar hrs worth of charge.. even a 4.5A for 5 hrs that is only 22.5Ahr worth of charge. That means you need to be running a gen for several hrs in the morning and several hrs in the evening and even that most likely will still fall short.

You need to audit your actual energy usage.

Your fridge uses battery to run the control board and open the gas valve.

Your water heater if it is DSI has a 12V control board and gas valve that like the fridge uses 12V battery.

The built in stereo system even if it is turned off sneaks 12V power..

Your propane gas detector also uses 12V battery power..

Furnace has a control board that uses 12V power even when the furnace is not running..

If you have a A/C unit with remote T stat, it too has a 12V control board that uses 12V even when A/C is not running..

If you have an inverter powered up all the time, it to uses 12V even when no 120V load is attached or turned on.

You can turn off all items and insert a Ammeter and see how much current is being drawn from the batteries without solar or converter running. Then one by one turn on those devices and record how much power is being used.. This will give you a better picture of your power usage.

If the total draw with just the fridge and water heater turned on is 1A or more you will have exceeded your potential 22.5Ahr harvest of your solar panel per day.

You most likely need more solar panel wattage and/or more gen run time..

I was aware that the fridge and Water heater would be parasitic draws, but never even considered stuff like the furnace (even when not in use) or AC. Propane detector is less than 100mA.
If I remove the fuses for these draws, will that disable them fully?

As I mentioned in the original post, my buddy has the same batteries but with 190W of solar panels and his batteries showed FULL charge on the hyDrometer. He has a Rockwood 2304 with similar accessories and doesn't seem to have any issues keeping his batteries at 100%.
According to calculations, he would only be harvesting about 50 A/hrs of energy daily.

And yet, he is harvesting TWICE of what you might get since his solar panel is nearly TWICE the wattage.. Which is TWICE the amperage..

When you are getting 2.2A he on the other hand would be getting around 4A.

When you are getting 4.5A, he would be getting almost 9A..

But even so, 9A is nothing much more than a trickle charge with a battery with 200 Ahr capacity..

See the problem?

You NEED MORE solar wattage..

Simple?

[3_tons]

You didn’t mention the type (number of stages?) or brand of the onboard charger, but the 13.2v reading might have been during float (??)…If it’s a Progressive Dynamics, you can use their optional Charge Wizard dongle to kick the voltage up to Boost… Either way, in the real world (calc’s and other issues aside…) it’s difficult for me to see how a single 100w panel can up-charge two Trojans…Considering wiring losses and latitude, etc, at best I see the lone panel as more of a maintainer than a true charger - FWIW, old rule of thumb is 100w per 100a/h - from my own GC batt experience that would be the absolute very minimum - JMO

3 tons

[Qwazert]

An update....

I took both T105's out of the RV this morning. One is on the Shumacher 6V 6A charger, the other on the NOCO Genius.
Shumacher showed about 4 amps of charge-rate at the beginning (about 2 hours ago) and has since fallen to below 2A.
SG reading is 1275 on all cells, so we seem to be making progress....cautiously optimistic so far.

I haven't taken any readings on the NOCO battery as it has a maximum 2A charge rate and is currently in "maintaining mode" with the green LED pulsing.
I will probably leave that one until this evening at the earliest.

As I overcome one problem, I start hypothesising about others....maybe I had "enough power" last year because the batteries were so new and we definitely had more sunny days than this year...it has been a dismal Spring and unimpressive Summer so far, in terms of hours of sunshine.

[Qwazert]

Gdetrailer wrote:

2.2A-4.5A solar charge?

You are severely and chronically undercharging T105 batteries..

I think you are severely underestimating your energy usage and needs which contributes to killing your batteries in a hurry.. Properly maintained even with 50% DOD but promptly recharged those T105s should net you 9-11 yrs worth of service..

Typically with solar you get about 5 peak solar hrs worth of charge.. even a 4.5A for 5 hrs that is only 22.5Ahr worth of charge. That means you need to be running a gen for several hrs in the morning and several hrs in the evening and even that most likely will still fall short.

You need to audit your actual energy usage.

Your fridge uses battery to run the control board and open the gas valve.

Your water heater if it is DSI has a 12V control board and gas valve that like the fridge uses 12V battery.

The built in stereo system even if it is turned off sneaks 12V power..

Your propane gas detector also uses 12V battery power..

Furnace has a control board that uses 12V power even when the furnace is not running..

If you have a A/C unit with remote T stat, it too has a 12V control board that uses 12V even when A/C is not running..

If you have an inverter powered up all the time, it to uses 12V even when no 120V load is attached or turned on.

You can turn off all items and insert a Ammeter and see how much current is being drawn from the batteries without solar or converter running. Then one by one turn on those devices and record how much power is being used.. This will give you a better picture of your power usage.

If the total draw with just the fridge and water heater turned on is 1A or more you will have exceeded your potential 22.5Ahr harvest of your solar panel per day.

You most likely need more solar panel wattage and/or more gen run time..

I was aware that the fridge and Water heater would be parasitic draws, but never even considered stuff like the furnace (even when not in use) or AC. Propane detector is less than 100mA.
If I remove the fuses for these draws, will that disable them fully?

As I mentioned in the original post, my buddy has the same batteries but with 190W of solar panels and his batteries showed FULL charge on the hyDrometer. He has a Rockwood 2304 with similar accessories and doesn't seem to have any issues keeping his batteries at 100%.
According to calculations, he would only be harvesting about 50 A/hrs of energy daily.

[Gdetrailer]

Qwazert wrote:

StirCrazy wrote:
100 watts on a PWM controler will give you a little more time but normaly won't keep your batteries charged unless your usage is verry low.

so the questions becomes, how low do you let your batteries get typicly when your camping. if you routeenly are using more than 50% of the capacity it will lead to shorter battery life, and if you run them dead you could fluke out and have no issues or you could kill the battery. also did you check every cell on the battery or just one with the hygrometer?

Steve

Hello Kamloops...coming to you from the Fraser Valley! 😄
I've tested the panel and its maximum output is about 4.5 amps...more than enough to keep a charge on batteries. Typically, it is about 2.2 a on a sunny day, so that should be sufficient to maintain FULL status.
The usage is low...the odd light now and then, maybe the water pump for a few seconds, but there is always the parasitic loads for the fridge and hot water tank.
All cells were tested and all had the same type of readings; 1225 - 1230.

2.2A-4.5A solar charge?

You are severely and chronically undercharging T105 batteries..

I think you are severely underestimating your energy usage and needs which contributes to killing your batteries in a hurry.. Properly maintained even with 50% DOD but promptly recharged those T105s should net you 9-11 yrs worth of service..

Typically with solar you get about 5 peak solar hrs worth of charge.. even a 4.5A for 5 hrs that is only 22.5Ahr worth of charge. That means you need to be running a gen for several hrs in the morning and several hrs in the evening and even that most likely will still fall short.

You need to audit your actual energy usage.

Your fridge uses battery to run the control board and open the gas valve.

Your water heater if it is DSI has a 12V control board and gas valve that like the fridge uses 12V battery.

The built in stereo system even if it is turned off sneaks 12V power..

Your propane gas detector also uses 12V battery power..

Furnace has a control board that uses 12V power even when the furnace is not running..

If you have a A/C unit with remote T stat, it too has a 12V control board that uses 12V even when A/C is not running..

If you have an inverter powered up all the time, it to uses 12V even when no 120V load is attached or turned on.

You can turn off all items and insert a Ammeter and see how much current is being drawn from the batteries without solar or converter running. Then one by one turn on those devices and record how much power is being used.. This will give you a better picture of your power usage.

If the total draw with just the fridge and water heater turned on is 1A or more you will have exceeded your potential 22.5Ahr harvest of your solar panel per day.

You most likely need more solar panel wattage and/or more gen run time..

[Qwazert]

StirCrazy wrote:
100 watts on a PWM controler will give you a little more time but normaly won't keep your batteries charged unless your usage is verry low.

so the questions becomes, how low do you let your batteries get typicly when your camping. if you routeenly are using more than 50% of the capacity it will lead to shorter battery life, and if you run them dead you could fluke out and have no issues or you could kill the battery. also did you check every cell on the battery or just one with the hygrometer?

Steve

Hello Kamloops...coming to you from the Fraser Valley! 😄
I've tested the panel and its maximum output is about 4.5 amps...more than enough to keep a charge on batteries. Typically, it is about 2.2 a on a sunny day, so that should be sufficient to maintain FULL status.
The usage is low...the odd light now and then, maybe the water pump for a few seconds, but there is always the parasitic loads for the fridge and hot water tank.
All cells were tested and all had the same type of readings; 1225 - 1230.

[2oldman]

hydrometer