AGM battery question

ShadowcatcherShadowcatcher Solar Expert Posts: 228 ✭✭✭
This is an unmitigated whine :cry:
The wiring in our teardrop trailer was messed up, (not done by me) and had the white leg of the AC and the DC negative 'grounded' to the frame and the Progressive Dynamics controller was screwed up as a result. How did I know the there was a problem, I could hear the battery boiling and the converter was stuck on boost at 14.4 V
The cost has just made itself known.
I had to replace the battery for my back up sump pump, one cell was dead, and decided to have the AGM battery from the trailer checked, and against a new battery it has half the capacity. I had specified a Lifeline (Concord) battery and paid for it, and they substituted a Chinese made AGM which is now junk. The company BTW is now out of business and I have the last trailer made by them and had to threaten legal action to get it, uncompleted.
The question, should I have been able to hear the battery boil if it was a true AGM

Comments

  • firerescue712firerescue712 Solar Expert Posts: 95 ✭✭
    Re: AGM battery question

    AGM Batteries are sealed. There is no water in this battery. The only thing you will hear from an AGM is when the vent pops. This means the battery is toast. It does not vent. The gases caused by charging a reabsorbed into the material inside the battery. I am by no means an expert. There are many here, though. Cariboucoot, BB, WayneinCanada are just a few that pop into mind. Why did they swap batteries with you? Did you contest this? Or was it too late?

    Have a safe and Happy New Years!
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: AGM battery question

    sorry for your loss. i guess it made no difference what agm battery you wound up with as it would've been toast. maybe you should go with cheaper golf cart batteries for now in case another mishap happens. you can always buy the agms 3-5yrs down the line should your setup prove itself viable with the golf cart batteries. if not, then you can add water to the flooded golf cart batteries and still use them even if some life was sucked out of them from abuse.
  • RCinFLARCinFLA Solar Expert Posts: 1,399 ✭✭✭✭
    Re: AGM battery question

    AGM have a 'squeeze' vent. When pressure builds up due to overcharge they will gradually start to vent. Sometimes you can hear a high pitch squealling sound but it is not very loud.

    During an absorb period you can sometimes see the ends of the battery bulge a bit.

    Grounding battery negative to chassis is common. Chassis grounding the neutral of AC power is not. Grounding neutral to negative terminal of battery should not cause battery overcharging by the charger.

    Ability to connect neutral to chassis depends on your inverter. Many low cost portable modified sinewave inverters do not allow their neutral to be grounded. On these, if you tie their AC output neutral to battery negative terminal they will blow their power fuse, or self destruct.

    I would check out your charger to see if it setup properly or possibly defective.
  • Blackcherry04Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: AGM battery question

    Using Progressive Dynamics, WACO, PowerMax or a IOTA RV Power supply / Converter as a dedicated Battery charger is not the best. They do what they are supposed to do, once they sense a load, the more they ramp up the power. I know they call them a " Battery Charger " and they will charge a battery , but you have to watch them. The IOTA with IQ4 does a ok job as a charger, but again it's quirky with a 7 hour absorb stage and 7 day repeat cycle. If you have a battery hooked to them and you forget a light or some drain on them, they will do just what yours did. If they ever get to the float stage, 1-2 amps will pull them out and they will stay there.
  • ShadowcatcherShadowcatcher Solar Expert Posts: 228 ✭✭✭
    Re: AGM battery question

    The PD converter is now working correctly I monitor it when it is plugged in, it is a three stage charger and well accepted with in the RV croud. The problem I think was that you had the AC and DC both through the converter and I cant think back feeding AC into the DC output didnt cause the converter to fail, PD replaced the converter with no question.
    The sound I was hearing was a distinct boiling sound which stopped the second I disconnected the battery from the converter.
    Nothing is now 'grounded' to the frame, a really bad idea particularly when you use copper lugs screwed to an aluminum frame. I had to rewire everything from the tongue back to the converter, one example the electric brakes were not working on the way home and I found they had never been wired in.
    I don't have an inverter or really need one, this is a teardrop 6X10 galley in the rear you cant stand up in it, big for a teardrop. It has a 185W panel and Morningstar MPPT controller all LED lights gas water heater and stove top...
    The amount of space that I have is limited, Large for a teardrop small for anything else.
    The album on the Teardrop & Tiny Trailer forum is http://www.mikenchell.com/forums/album_personal.php?user_id=8503 which has lots of pictures and the story of how the trailer was built.
    One of the other factors is I am purity much stuck with an AGM because of battery placement, in the tongue box with a number of electrical items including air pump and with little ventilation for vented gases.
  • techntrektechntrek Solar Expert Posts: 1,372 ✭✭✭
    Re: AGM battery question
    RCinFLA wrote: »
    Grounding battery negative to chassis is common. Chassis grounding the neutral of AC power is not.

    True. But the ground wire should be attached to the trailer's chassis.
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
  • ShadowcatcherShadowcatcher Solar Expert Posts: 228 ✭✭✭
    Re: AGM battery question

    If all of the lights etc. have ground wires there is no reason to ground to the frame. I have seen a number of threads on The T&TTT forum with wiring problems,turn signals not working on both cargo trailers being converted and Red trailer and Harbor Freight trailers i.e. and the final outcome in each case was that wiring light sockets with a separate ground fixed the problem.
  • Blackcherry04Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: AGM battery question

    Good Luck to you, sounds your on the right track. I know that RV crowd, I am one of them. They wear out a set of jumper cables for me every year. Your correct about the PD it does have 3 Stage charging ( or something like it, but not exactly ).
  • techntrektechntrek Solar Expert Posts: 1,372 ✭✭✭
    Re: AGM battery question

    Every RV I've owned or have seen has the frame grounded. You might be ok since a teardrop doesn't have a shower, but I wouldn't want to take a shower in a camper hooked up to shore power w/o proper grounding.

    OT, since you have a teardrop you'll appreciate my current camper:

    Attachment not found.
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
  • Blackcherry04Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: AGM battery question

    Is it possible to get a glossary of the terms being used.

    1) Frame
    2) Chassis
    3) Ground 12 V or 120V AC or DC
    4) Earth Ground
    5) Neutral

    As the reply's go back and forth it gets confusing.
  • bmetbmet Solar Expert Posts: 630 ✭✭
    Re: AGM battery question
    Nothing is now 'grounded' to the frame, a really bad idea particularly when you use copper lugs screwed to an aluminum frame. .

    I just purchased an RV with an aluminum frame. What is the proper way to ground it with copper wiring?
  • RCinFLARCinFLA Solar Expert Posts: 1,399 ✭✭✭✭
    Re: AGM battery question

    Grounding or 'common connections' can be very confusing.

    Neutral is the return line for the utility company. In U.S. the regulations are that there will a single point of earth grounding of the neutral at service entrance. There will be a physical grounding rod driven into the earth that connects this single point to the neutral wire coming from the utility. If you have overhead power lines coming into your house, again in U.S., the neutral return is the non-insulated support cable, around which there are two insulated wires wrapped that are the 240 vac feed. The neutral is like a center tap of a 240 vac output transformer. It may also be phyically earth grounded at the utility pole.

    Chassis and frame are pretty much the same thing. On your RV it is the metal frame and any metal that connects to it. On your car it is the frame and engine block which also has the negative terminal of the battery connected to it. You cannot rely on a trailer hitch to provide the electrical connection to the trailer so there will be an extra wiring connection for negative return for your trailer lights. Your trailer may or may not connect this negative return to its chassis although it is commonly connected. If your trailer has a metal skin you should check that it is electrically connected to the frame that supports the trailer body.

    Most people are not going to physically drive a grounding rod into the earth to connect their trailer frame to the chassis/frame when camping. The ramification of this is care must be taken when an extension cord is supplying power, also referred to as 'shore power' from boating industry. The neutral is the wider prong of 120vac outlets. On your trailer this should not be connected to frame/chassis. Any extension cord used to shore power should be a three conductor cord with the green 'ground' wire of the cord plug connected to your trailer's chassis/frame. This ensures your trailer's metal parts are connected to the shore power ground.

    Same thing should apply when connecting power from a portable generator or inverter.

    The primary principle is for normal conditions no current should flow in the ground/chassis, frame. The grounding is for safety if something fails. If you have a battery in the trailer that relies on the vehicle alternator for charging then the connections between vehicle and trailer should be large enough to handle the charging current from the alternator to trailer battery. Again, you may have a chassis to chassis connection through the trailer hitch but it should not be used to carry the charging current. A separate, properly sized wire/connector-plug should be used.
  • Blackcherry04Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: AGM battery question

    Thank's RC, what happens is that posters or readers see different terms and get confused. I just read a court case of a death in a RV with a Kitchen light and contact with a Faucet that electrocuted a lady. It was all because of a 3 way switch where just the neutral was being disconnected and the earth ground was never connected.

    I try to never take for granted that a shore power connection is grounding correctly. Get out your multimeter and check them.
  • RCinFLARCinFLA Solar Expert Posts: 1,399 ✭✭✭✭
    Re: AGM battery question

    The most common problem is stepping from the outside, standing on the ground, to the trailer. You put your hand on the metal frame of the trailer door while still standing on the earth ground.

    Many portable inverters do not allow connecting their neutral to their chassis (ground prong on plug). They also have some small EMI (electro-magnetic interference) bypass capacitors from their two AC terminals to their case (metal chassis). This can cause some 'tingling' when touching some appliances that also have a capacitor from their AC power connections to their chassis unless the appliance's chassis is 'grounded' to the inverter chassis, 'grounding' meaning the inverter case is electrically connected to appliance case.
  • techntrektechntrek Solar Expert Posts: 1,372 ✭✭✭
    Re: AGM battery question
    RCinFLA wrote: »
    Again, you may have a chassis to chassis connection through the trailer hitch but it should not be used to carry the charging current. A separate, properly sized wire/connector-plug should be used.

    To add to what you said, on the car side of the Bargman connector (the big round 7-pin connector used for campers), the +12 volt line should be at least 10 gauge and run directly to the battery, connected via a 30 amp DC circuit breaker or fuse. The negative line should be at least 10 gauge, preferrably 8 gauge, but it can be smaller if it is securely connected to the vehicle chassis near the Bargman. Keep in mind that the negative line carries the combined load of everything - brake lights, brakes, running lights, battery charging, fridge when on 12 volt mode, so don't skimp on that connection. Or the +12 line which will carry all battery charging and fridge current, the biggest loads.
    4.5 kw APC UPS powered by a Prius, 12 kw Generac, Honda EU3000is
  • ShadowcatcherShadowcatcher Solar Expert Posts: 228 ✭✭✭
    Re: AGM battery question

    Back to the original question Is this a true AGM battery, can they boil?
    I will be replacing it shortly with a Lifeline

    In our case the frame and chassis are both aluminum and the skin Filon so weight is about 1500# wet. Both pos and neg to the plug were run using 10ga direct to the battery on the TV. There is a circuit breaker at the battery in the TV and a fuse in the line to the battery in the tongue box. There is also a 10 ga line going to the back of the Subaru to power the Waeco refrigerator which rides in the back until we set up.
    I do like the R-pod and if we were to go for a standie that might well be it. But we have everything it does (except the inside bathroom) and I can tow it with the Subaru.
  • BB.BB. Super Moderators, Administrators Posts: 32,027 admin
    Re: AGM battery question

    "Boiling" meaning excessive gas production... Yes. Many AGM's have a small catalyst capsule in them (pladium or something) that "combusts" the H2 + O2 back into H2O. If there is too much gas being generated, the catalyst may overheat (melt the cap) and/or the battery may vent the gasses and electrolyte too.

    A couple of interesting threads about AGM batteries:

    Low rest voltage on GNB absolyte IIP cells
    Sulfated Lifeline Concorde AGM Batteries

    Concorde seems to claim they are very resistant to high charging voltages (not sure I would make it a habit).

    Will you hear a "boiling sound"--Not sure. Others hear have reported they can sometimes hear a whistling sound when the batteries are venting.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • Blackcherry04Blackcherry04 Solar Expert Posts: 2,490 ✭✭✭
    Re: AGM battery question

    I'd say when you see the top separated from lower case of one or a post melted off that they were making some kind of a sound before failure. I guess it would depend on the Volts and AMP's your charging source was putting into it. They will defiantly leak electrolyte when they fail. I have interest in a certain type of car where the battery is tucked in the rear fender and they have always had AGM's standard with a drain tube and they leak and cause a lot of damage when over charged. Choosing the correct charging source is important with them, not all chargers have the correct algorithm to support them or GEL batteries. ( although they may claim they do )
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