Battery disconnect and battery charge

[creativepart]

Originally Posted by imnprsd

creativepart: I just think you could have framed your response in a question instead of trying to discredit the subject you obviously know nothing about.

I'm sorry for not stating as a question the info I read online about Pulse charging and that it offended you. That was not my intention.

Good luck on bringing your house batteries that won't hold a charge back to life. We all would love to learn that a $36 device is the answer to all of our battery woes.

[imnprsd]

No offense taken.

UPDATE: After monitoring the pulse charger output voltage, it does indeed vary from 12.8-14.2, but it does not show how much charge-current (Amps) is present. This is probably because the max amps the pulse-charger can output is 8A, and when you have 4 house batteries that's not going to be harmful no matter how long you leave the pulse-charger connected.

I'm still conducting a field test and will report conclusions next week.

So far I have been able to confirm my battery bank will accept a charge at normal rates. The voltage after coming to a rest measures 12.7V, indicating 100% fully charged battery bank, but what is not working right is that the battery bank can't handle any power drain of more than 250W. ...So while I CAN power lights, TV and other small accessories for a day, I CANNOT power my residential refrigerator for than 15 minutes -- and then my inverter shuts off due to low voltage.

Note: There are also physical signs of battery case deformations, but I have always seen this in the past with other battery banks.

So right now I would say the chances of this pulse-charger working on an already sulfated bank of 4-6V-GC2 golf cart batteries is not looking good!

[BobC]

Years ago I had two 6v golf cart batteries in a sailboat I'd just purchased. They wouldn't hold a charge and I thought they were dead. I took them into a full-service battery shop and they kept them for a couple of days, did their magic (de-sulfating?). The batteries were good for several more years. I was impressed that the shop didn't try to sell me new batteries.

[imnprsd]

There is another term I came across called "False" Capacity." Apparently, this is when a battery can meet the voltage tests for being at full charge, and yet be much lower than it's original capacity. This occurs when plates are damaged, sulfated, or partially gone from long use. And the result is a battery that may give the appearance of being fully charged, but in reality acts like a battery of much smaller size (20% or less). See BatteryUniversity.com for more information.

This reference goes on to say: The same thing can occur in gelled cells if they are overcharged and gaps or bubbles occur in the gel. However,

Batteries usually go bad for other reasons before reaching this point, but if your batteries seem to test Okay, but lack capacity, aka life, and you find they go dead very quickly under load, it's possible you have a bad battery (bank) and you are reading "FALSE CAPACITY" on the voltmeter and/or hydrometer. (Not to be confused with reading surface charge, which is something different.)

So here are some questions I need help sorting out:

* How does "Repair Mode" work on these pulse-chargers?

* How is "Repair Mode" different than the "Equalization" or "Conditioning" phase our inverter/chargers use?

* I understand how voltage is a potential difference measurement between the positive and negative plates, but why won't current flow out of the battery if you can get current to flow into the battery?

I think the answer is this: When I left my RV in storage for 10 months I forgot to disconnect the battery cables. (I don't have a battery switch like on a boat. And simply disconnecting the "Battery Disconnect Switch" is not the same as removing the battery cable from the house batttery post.)

My house batteries were extremely dead, but they did come back to life for 1 week and then "poof." ...And now my current situation appears I am getting "False Capacity" measurements on my voltmeter and hydrometer. It's as if someone put mud in my batteries and I only have 1" of active battery plates on the top... where I am measuring voltage and using a hydrometer to verify SOC. I.e,. my house batteries are acting like they are 1" tall instead of 10"!!!

I also have checked all my battery cables and cleaned the rust of the 15 year old 300A fuse block and at the positive and negative battery posts and chassis grounds. And I have replaced the terminal ends on the inverter and battery disconnect cable, which didn't need clipping.

So I'm still trying to verify one or more of these things are the problem:

A) Bad batteries? (Of which I am 95% sure this is the problem.)

B) Bad inverter (draws too much power)?

C) Bad 9" long "00" battery cables that I use to connect my 4-6V-GC2 batteries in series & parallel to deliver 430AH at 12V? ...However, I used welding cable this time, but I don't think that's a problem? Isn't welding cable with pressed on lugs supposed to be better then battery cable?

D) Bad 300A fuse even though it looks good?

[BobC]

Originally Posted by imnprsd

I think the answer is this: When I left my RV in storage for 10 months I forgot to disconnect the battery cables. (I don't have a battery switch like on a boat. And simply disconnecting the "Battery Disconnect Switch" is not the same as removing the battery cable from the house batttery post.)

I don't understand why activating the disconnect switch to disconnect the battery wouldn't act the same as removing the cable unless it's faulty. Can you elaborate?

[Wyatt]

Originally Posted by BobC

I don't understand why activating the disconnect switch to disconnect the battery wouldn't act the same as removing the cable unless it's faulty. Can you elaborate?

I don’t know about his set up, but on mine, there are several parasitic loads that remain even after turning off the coach battery disconnect switch. I believe one is the propane gas detector, and I know another is my Victron monitor...

[BobC]

Originally Posted by Wyatt

I don’t know about his set up, but on mine, there are several parasitic loads that remain even after turning off the coach battery disconnect switch. I believe one is the propane gas detector, and I know another is my Victron monitor...

I suspect this varies by model and/or year. On my 2002 35U, the battery disconnect switch does disable the propane alarm.

[Goodspike]

Originally Posted by BobC

I suspect this varies by model and/or year. On my 2002 35U, the battery disconnect switch does disable the propane alarm.

I think the only thing my trailer doesn't disconnect is the tongue jack. I think even the emergency brake gets disconnected, but not certain of that. Probably worth looking into.

[thataway4]

I have been using Pulse Tech products (patented in 1989) for over 25 years in both RV's and Boats. and they definitely appear to prolong the life of batteries. I generally get 5 to 7 years out of batteries, depending on the application. I had 7 years service on two Group 31's in parallel starting bank for a Cummins 8.3 L in an RV. They were echo charged thru a BIRD relay system. The Golf Cart house bank lasted over 5 years, running a residential 22 cu foot refrigerator freezer. (I had solar panels for charging, but not enough for 100%, when boon docking.)

The Pulse Tech can be used wired directly to the battery, not requiring external power: Powerpulse https://www.impactbattery.com/power-...r-pp-12-l.html

Here is information on Pulse Tech: https://www.pulsetech.net/our-techno...echnology.html
(I don't endorse any specific site or product, it may be cheaper on other sites.)

The Power Pulse will work well with solar chargers. I kept an RV and Boat in Las Vegas both with solar power to maintain the batteries and kept one of the pulse chargers on the house banks of each. It would often be 6 months between trips where I used these.

I have also been using VSR/AVR for many years. They are very helpful in many cases. For the RV, with a fairly large house bank, I suggest an Echo Charger, which as by Xantrex for the chassis battery maintainer. You only need a small "Trickle "charger to keep up with parasitic loads on the chassis battery, and any self discharge.

I have not delved into the profile of the "converter/charger" on my current VIA, but in general I have found that "smart" chargers, such as the NOCO Genius (and a number of chargers) will do a better job of maintaining the house banks than the converter / chargers.

The way that your use or abuse batteries has a lot to do with longevity. I always recommend that a Shunt based state of charge meter be used: Victron 700 series is what I am currently using in several applications. You can monitor voltage, amps in, amps out, cumulative use of amps, watts, mid point voltage and state of charge. It is important not to abuse batteries by discharging them excessively. I consider for a FLA battery a voltage of 12.2, in resting state (no load or input current for an hour) to be 50% discharged, and that is where I try and draw the line for discharge before recharging.

[imnprsd]

I will explain what I learned about battery charging and maintaining after I tell you I could not repair my 4-GC2-6V Golf Cart batteries.

I also called Pulse Tech and they explained you can often repair a dead battery, providing there are NO internal (cell) shorts. And since most of the market is targeting 12V engine start batteries there is not much written about golf cart deep cycle batteries.

What I was able to clarify (in my mind) are these things:

* When you put your coach in storage it is very important to hook up a Battery Maintainer (BM). There are several types or flavors of BMs to choose from, but basically they fall into 3 categories: trickle charger, pulse charger, and variations of both charger and frequency pulse devices that available in different amperage.
...Or if you have solar panels on your RV then your solar charge controller will maintain your battery bank... and your engine battery bank too if you have a VSR or battery combiner. (This is the best way to go if you park outside.)

My problem is that I park in a Pole Barn and I can't utilize my solar panels and there is not AC power.

==> Therefore, if you put your RV in storage it's very important you disconnect the positive battery cables from the house and engine batteries if you do not have a high quality battery selector switch, like those from Blue Sea. I.e., simply turning off the Battery Disconnect Switch (aka Salesman Switch) is not good enough, because you may find your batteries so dead that they cannot be recharged.

* Trying to repair a dead house battery requires you to connect 2-6V batteries together to make 12V; and because these 2 golf cart batteries are are 215AH at 12V, according to Pulse Tech, it may take you 2 weeks to bring these back to life... and there is no guarantee you will be successful.

==> So I'm not willing to pulse 4 golf cart batteries for 4 weeks to find out if this will work, but that is because a also have these concerns:

* The sides of my batteries are slightly bulging (minor concern)

* The top of my positive battery post was bulging up a bit -- and the tech at Les Schwab in Montana says he sees this when batteries freeze.

So this is another very good point, because the secondary purpose of putting a trickle charger on a battery in storage is to make sure it does not freeze.

* And then we tested the cold cranking amps in each of my deep cycle batteries, because the battery tester at Les Schwab uses cranking amps as a parameter to graph % load. I.e., my batteries all exhibited a wide array of cranking amps, and these are: 180, 240, 300, 480.

Note: CCA is the amount of current or amps a battery can provide at 0 °F (−18 °C) for a 30 second duration until the battery voltage drops to unusable levels.

Consequently, with the battery tester set to 200CA... all of my batteries pass, but if the battery tester is set to 400CA then all the batteries would fail.

Further, it is my understanding 6V deep cycle batteries will produce ~650-700CA even though they don't rate deep cycle batteries this way.

* So the basic problem load testing a golf cart battery is the fact the tester everyone (90% of the battery shops use) is based on a 6V or 12V or 24V and they can't test for heavy current loads... like we do when we turn on our inverter to run a microwave or residential refrigerator.

* So the best load test is right there in your coach.

CONCLUSIONS

* Use a battery maintainer or trickle charger whenever your coach is left in storage; and if you live in climates that reach freezing for more than 3 days in a row it's very, very important you use a maintainer of some sort if you want your deep cycle batteries to lase more than 2-3 years.

* Disconnect your positive battery cables if you don't have a high quality battery disconnect switch!

* According to Pulse Tech, if you have 4-6V-Golf Cart batteries then you need 1 Pulse Device for each 2-6V batteries in series (12V side). So 4-6V batteries will require 2 pulse chargers. However, if you have 3-12V batteries you can use one maintainer or pulse charger since all your 12V are connected in parallel.

* Clearly, it is better to maintain your batteries vs. trying to repair them.

I decided to trash my 4-GC2-6V batteries because that all were displaying different cranking amp ability. I.e., when you have a bad battery it's like cancer and will affect each battery in the line. Likewise, this tells me my battery cells are NOT EQUALIZED and therefore each battery is working against the other!

Consequently, I'm not sure which is better: 4-6V deep cycle batteries hooked up in series and parallel to deliver 430AH at 12V... or 3-12V deep cycle batteries hooked up in parallel to deliver 450AH at 12V?

I have used both and the 6V deep cycle batteries seemed like they had more useful life between charges, which means I ran my generator less when I'm boondocking; but both solutions are costing me $500-$600 every 2-3 years to replace.

I thought about adding a smarter Converter Charger to my power grid, but now I think a solar pulse charger will be best.

So testimonials from "thatway4" are much appreciated. Let's just keep in mind that storing an RV with available shore power or solar power is not the same as storing an RV without any battery maintenance going on... and if you live in sub-32F then that's an even bigger problem because you battery will freeze and cause premature shorts!

Alternatively, you can go to Sam's Club In Puerto Penasco on your way to Rocky Point and buy 6V-GC2-Golf Cart Batteries for $300.

[imnprsd]

So I ended up buying 4-6V-GC2 Golf Cart batteries from Costco for $99/ea and no tax in Montana.

These batteries showed a full charge, but after putting a load on them it was apparent they were only 50% SOC. So I took my time charging them slowly for 2-days, I fired-up my inverter and verified it was operating normally!

So the good news is that I did NOT need to replace my old Dimensions Qusai-Sine Inverter, but I did decide to buy the Victron Smart Blue Charger (IP-67), because it came with a Bluetooth App, which allows me to monitor and control the charger functions and I did not want to bother with a second remote panel, but I did want to see what all this bluetooth stuff was about.

Amazon $133: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

==> Bluetooth is nice to see what is going on and it's great for trouble shooting or to make you feel more at ease that everything is working properly. Otherwise, it's just a fancy on-off switch, but I would recommend it, and if you really want to create your own battery charge modes... you can! ...But you probably won't!

I also went with Victron because they seem to be growing their market share in the solar market and they have received a lot of favorable reviews. Plus if I decide to "grow" my power grid and buy a "pure sine" inverter someday; or if I need to replace my "solar controller," then I can monitor and control all these Victron bluetooth devices from my cell phone, which is nice.

I also like trying newer technology with Amazon's return policy, but this time I will be keeping this IP67-17A charger. Why?

* Truth is: My 420A Battery bank is only good for 225AH if you follow the 50% rule of recharging your batteries at this point.

* So all I really need is a charger that can charge 225AH in a reasonable amount of time. And with a 17A charger it will only take 13.2 hours to fully recharge my battery bank... in theory.

* In actuality, it will take 20hrs to complete a 50% SOC charge cycle and that's never a problem for me since I always stay more than 1 day when I have shore power available.

* Therefore, I use to think buying a 100A charger was the best way to go, but I have since learned the best way to charge a bank of batteries is to use a new technology charger... and to charge it slowly! ...NOT FAST!

* The faster you charge your house batteries the more likely you will only reach 90% SOC... or less over time.

* I also now believe there is no such thing a "repairing" a bad battery to more than 50-70% SOC; and while this maybe okay for an engine-start battery... it does us deep cycle battery owners very little good. ...Just put a load on a weak house battery bank and you will see what I mean.

* Pulsing also is not something you can do reliably to a bank of 4 batteries. Why? Because when you use "pulse-repair" on a group of batteries you will end up with different cell voltage and this will work against you when you assemble you battery bank in series and parallel.

==> Remember, one bad apple can spoil the hole bunch and this applies to batteries too. Especially in series!

* In order for you battery bank to function in an optimal manner, you need every one of those battery cells to be the same voltage, and the same internal resistance, which is impossible to achieve with a pulse charger unless you let it run for weeks on all 4 batteries at one time... and even then you don't know what results you will get, but you do know the most you can hope for is a repair of about 50% to 70% of new. And that's not good enough for deep cycle batteries!

* All my research shows you cannot repair a battery back to a fully charged state. So I have given-up in the ideas of using a pulse-repair-charger on a bank of deep cycle batteries. However, they may be some real value to using a pulse-repair-charger on a single, dead, engine-start battery!

* Most higher-end battery charging algorithms will include an "equalize" mode or "condition" mode and they may use a form of pulse-repair. I can't say for sure, because no one really likes to talk about it.

==> I now believe it is apparent that if you want your batteries to last the longest you will:

* slow charge them whenever possible;

* maintain them properly, which includes a battery maintainer in addition to your 3-stage charger; and you will...

* recharge them often and above 50% SOC all the time.

MORE OBSERVATIONS

* Be sure your bank of batteries is connected properly.

* Every battery charger will utilize it's maximum current possible during the "bulk" charging stage. Therefore, one way to minimize that is use a small amp charger. For example, don't rush off to buy a 100A charger when a 45A charger will work just fine.

* Use a new technology smart charger. I chose Victron IP67-17A charger, but that's because I can always turn on my Dimensions 100A charger if I only have 1 night to pump-up my batteries. And for all the other times I spend in a camp spot with shore power of 2 or more nights... when what's the rust to charging my batteries fast? ...Answer. There isn't any rush. So use the slow charger.

* Use a battery combiner or VSR to your house batteries can charge while you drive; or solar panels; but solar will not power your residential refrigerator alone; and the sun has to be shining, but every little bit helps!

* Understand that your Solar Charge Controller is like a dumb charger. Which means my Victron 17A charger, plus my variable 0A-19A Solar charger, means I can pump up to 36A on a sunny day;l and that's plenty fast charge if I only need to charge 225AH at 50% SOC. (Less what I use for lights, which means I only need 2-3 days to recharge my battery bank without using the Dimensions 100A Charger.)

Consequently, with my Victron-17A charger l will be leaving my Dimensions 100A charger turned "off" more often now that I better understand my power grid and I will not be in any hurry to charge my house batteries. And maybe now I can get more than 2.5 years of life out of them! TBD.

* Alternatively, I think if my Dimensions Charger every "crapped-out" then I would still keep it for the inverter, and turn the charger portion "off" on my remote panel. Then I would buy a 45A Progressive Dynamics Wizard Charger, and put it next to my Dimensions Inverter...

...and for power I would plug the cord into my Engine Block Heater wall socket... so I can switch it on-and-off from inside the RV... and as for the Converter-12V-line-out? ...don't use it. ...you don't need it.

Good luck extending your battery bank life.