Battery Losing Charge!!

[uncle_bob]

Hi

If the battery goes from ~10V to ~14V when you plug in shore power ... you have a problem. Either there is a bum connection between the charger and the batteries or the batteries are toast.

A multimeter reading on the battery posts will tell you which it is. If the batteries *do* go immediately to ~14V they are the issue. If the charger goes to 14V and the batteries don't ... start looking for a wiring problem. Next check is at the output of the converter. ( = make sure it really is at 14V). Work from there towards the batteries.

You do want to work out what's going on before you start replacing things. Your charger could indeed be broken ... it happens. You could have a loose wire, that's more unusual but not impossible. Batteries (even good ones) do die an early death sometimes. Replacing the batteries if something else is the problem ... that gets expensive. Also keep in mind that one problem may have caused the batteries to die, you may have multiple problems.

As mentioned above, batteries get replaced in pairs. Opinion is split between the "go cheap on sale" crowd and the "get the best no matter the cost" end of things. It's very much up to you and your credit card ....There is no one size fits all answer.

If you are going to get into swapping parts out, consider adding something like a Victron BMV-712 to monitor the system status. With any battery system, it's better to have status information you can trust. There are other similar current shunt based systems, they also work pretty well.

Bob

[Delores]

Thanks

[Alex AVI]

Originally Posted by uncle_bob

If you are going to get into swapping parts out, consider adding something like a Victron BMV-712 to monitor the system status. With any battery system, it's better to have status information you can trust. There are other similar current shunt based systems, they also work pretty well.

Bob

UNCLE BOB - I am not having any of the extreme batt issues as the OP. My 2018 is always plugged into shore when not in use. I have been reading this thread (along with some older ones) because soon (weather is getting more mild), I will be replacing the PC BIM with Blue Sea ACR 7622, the Atkinson solar controller with Victron MPPT Smart Solar 100/50 and Victron BMV712 batt monitor. I think this may be redundant w/ Smart Solar bluetooth, but I can figure this out myself and not the purpose of my query. So in the meantime, my house batts get charged by Magnum, and for the most part full charge this last 3 summer months is around ~12.5v. Without a good shunt batt monitor, I guess that value isn't too reliable. My AI stored in my enclosed garage still gets above 105°F temp inside the rv in the height of summer (115°F outside of garage). I read in one of your 1yr-old post this :

"Next gotcha is temperature. If it's hot out and the batteries are hot as well, move all the voltages above down about a half volt. If they are cold (as in down towards freezing) move all the voltages up by a half volt."

So, is my ~12.5v full charge reading in line with the temp effect of extreme heat you alluded to? If this is the case, then I guess considering all factors, my batts are not doing too badly?

PS - tire temps inside the garage per TPMS read 100-105°F also. I choose to not run the garage swamp cooler and AI house A/C because we get a HUGE electricity discount in our rates when we minimize kwh used between 2pm-7pm in summer. We pay winter rates for 19hrs in exchange for voluntary minimum use the other 5hrs. If I ran the A/C, the huge savings disappears.

[uncle_bob]

Originally Posted by Alex AVI

UNCLE BOB - I am not having any of the extreme batt issues as the OP. My 2018 is always plugged into shore when not in use. I have been reading this thread (along with some older ones) because soon (weather is getting more mild), I will be replacing the PC BIM with Blue Sea ACR 7622, the Atkinson solar controller with Victron MPPT Smart Solar 100/50 and Victron BMV712 batt monitor. I think this may be redundant w/ Smart Solar bluetooth, but I can figure this out myself and not the purpose of my query. So in the meantime, my house batts get charged by Magnum, and for the most part full charge this last 3 summer months is around ~12.5v. Without a good shunt batt monitor, I guess that value isn't too reliable. My AI stored in my enclosed garage still gets above 105°F temp inside the rv in the height of summer (115°F outside of garage). I read in one of your 1yr-old post this :

"Next gotcha is temperature. If it's hot out and the batteries are hot as well, move all the voltages above down about a half volt. If they are cold (as in down towards freezing) move all the voltages up by a half volt."

So, is my ~12.5v full charge reading in line with the temp effect of extreme heat you alluded to? If this is the case, then I guess considering all factors, my batts are not doing too badly?

PS - tire temps inside the garage per TPMS read 100-105°F also. I choose to not run the garage swamp cooler and AI house A/C because we get a HUGE electricity discount in our rates when we minimize kwh used between 2pm-7pm in summer. We pay winter rates for 19hrs in exchange for voluntary minimum use the other 5hrs. If I ran the A/C, the huge savings disappears.

Hi

If your batteries are up around 110F, then full charge voltage will be *lower* than the magic 12.6V many use. Indeed this is where the risk of "over voltage" on the batteries comes in when charging them. What matters is the temperature deep in the battery. That will always "lag" the outside temperature by a bit. Getting batteries really hot takes just the wrong combo of sun on the battery area / temperature / wind.

Exactly how much the voltage changes and at what temperatures unfortunately is a "that depends" sort of thing. Battery chemistry impacts how things shift. Manufacturers realize this and try to build batteries to match the average temperatures in an area. One type of battery chemistry goes to Alaska, a different tweak goes to Arizona. How that works in the age of Amazon ... likely not well ...

=====

The BMV-712 and Smart Solar charger are complementary to each other. One does not make the other redundant. They actually have a Bluetooth based networking thing they do to work together. You put a temperature monitor on the BMV-712 and it will send the data to the MPPT. Indeed there's more to it than that, but in the context above, it's a fairly significant feature.

Bob

[Alex AVI]

Originally Posted by uncle_bob

Manufacturers realize this and try to build batteries to match the average temperatures in an area. One type of battery chemistry goes to Alaska, a different tweak goes to Arizona.
=====
The BMV-712 and Smart Solar charger are complementary to each other. One does not make the other redundant. They actually have a Bluetooth based networking thing they do to work together. You put a temperature monitor on the BMV-712 and it will send the data to the MPPT. Indeed there's more to it than that, but in the context above, it's a fairly significant feature.

Bob

UNCLE BOB - I appreciate the info. I was curious about the fact that our rigs were built in OH and being I am in Las Vegas, batteries may not necessarily be optimum for my local temps for maximum life expectancy. But that's just the way it is, until they need replacement from my local source.

Thank you for elaborating on the BMV & MPPT compatibility. I read up on it last night and deduced from their website the same. Hoping to get my upgrades done in a few weeks coz by that time, temps will only be in the 90's.

[uncle_bob]

Originally Posted by Alex AVI

UNCLE BOB - I appreciate the info. I was curious about the fact that our rigs were built in OH and being I am in Las Vegas, batteries may not necessarily be optimum for my local temps for maximum life expectancy. But that's just the way it is, until they need replacement from my local source.

Thank you for elaborating on the BMV & MPPT compatibility. I read up on it last night and deduced from their website the same. Hoping to get my upgrades done in a few weeks coz by that time, temps will only be in the 90's.

Hi

Back in the "good old days" one of the big differences between Las Vegas and the north east was the amount of headroom above the plates for extra electrolyte. The assumption was that in the desert heat, you would be unable to keep things topped off without a bit of "spare" in the battery.

One result of this was that the "super duper high capacity" batteries were not going to do the trick in Las Vegas. They packed the plates in as tight as they could to get the capacity. Either they just didn't advertise those batteries out there or they didn't stock them in the stores.

That info is from a while back. I haven't seen any recent studies on how they handle things today. They may just ignore it and take the hit in higher warranty costs (and charge accordingly) .... who knows ....

Bob

[Alex AVI]

Originally Posted by uncle_bob

They may just ignore it and take the hit in higher warranty costs (and charge accordingly) .... who knows ....

Bob

UNCLE BOB - they may just take the warranty hit coz in the 20 yrs we've lived here, all my batteries (regular cars, no rv until this year) have been replaced under warranty, a few even twice. Usually 3-4 yrs they would die in hottest day of summer, of course.

[uncle_bob]

Originally Posted by Alex AVI

UNCLE BOB - they may just take the warranty hit coz in the 20 yrs we've lived here, all my batteries (regular cars, no rv until this year) have been replaced under warranty, a few even twice. Usually 3-4 yrs they would die in hottest day of summer, of course.

Hi

Welcome to engineering by accountants ....

Bob

[Delores]

Update from my OP. I have ordered 2 replacement batteries, same type as original installed in 2016 Interstate. Should arrive next few days. I have never looked under coach, so I’m going to take to an auto shop with a lift to have them installed. I would like to know best practices for keeping the new batteries properly charged so same problem doesn’t occur.
FYI, parked in driveway when not in use and plugged in 20 amp house power. Everything is usually off and will only turn on appliances if needed. Is there any harm in keeping plugged 24/7 or will new battery automatically run down if unplugged and not used for a week or so? Also, if battery disconnect switch is OFF, will that keep batteries from being drained when not in use.

[68 Overlander]

Originally Posted by Delores

Update from my OP. I have ordered 2 replacement batteries, same type as original installed in 2016 Interstate. Should arrive next few days. I have never looked under coach, so I’m going to take to an auto shop with a lift to have them installed. I would like to know best practices for keeping the new batteries properly charged so same problem doesn’t occur.
FYI, parked in driveway when not in use and plugged in 20 amp house power. Everything is usually off and will only turn on appliances if needed. Is there any harm in keeping plugged 24/7 or will new battery automatically run down if unplugged and not used for a week or so? Also, if battery disconnect switch is OFF, will that keep batteries from being drained when not in use.

I keep forgetting that unit does not use the Parallax but curious what battery Airstream used in it. If it's Interstage, I keep getting calls on them not lasting more than a year or two with ANY charger. Even my pic-up ate a pair in 18 months and I'm not a fan. Not sure if Airstream is doing this but many OEMs for the sake of liability are leaving the sniffers (LP and CO detectors) out of the disconnect switch. Might want to check that.

[Delores]

Lifeline battery.

[Alex AVI]

Originally Posted by Delores

FYI, parked in driveway when not in use and plugged in 20 amp house power. Everything is usually off and will only turn on appliances if needed. Is there any harm in keeping plugged 24/7 or will new battery automatically run down if unplugged and not used for a week or so? Also, if battery disconnect switch is OFF, will that keep batteries from being drained when not in use.

DELORES - Good news. AFAIK even if there is some trivial negatives for keeping plugged in 24/7, the MANY benefits outweigh the negatives. 3 being batteries always on float (if solar is not generating enough amperage) and fridge can stay cool (even if not 32°F) and have vent fan on when hot. FYI my unit is now 7mos old and have been plugged in 24/7 when in garage. So far, so good. On 2018, as long as plugged in, does not matter if Disconnect Switch is on/off. It will charge from solar/shore power out in sun or just shore when no sun. I think other model years don't charge from shore if Disconnected, but don't know which years the change was made.

[68 Overlander]

Originally Posted by Delores

Lifeline battery.

I went back and read the posts I had missed. You did indeed mention Lifeline GPL-24. They have a 5 year warranty and I have warranties two in 13 years and one was a starting battery so something is going on. I know you don't know that the PO did to them but I can't fathom such neglect. Unfortunately since you bought the coach second hand, Airstream/Lifeline will not likely be of much help. I certainly would have considered Fullriver. They have a 7 year/2 year free replacement and just can't say enough good about them. That is having been a Lifeline distributor all these years. Lets see if we can figure out what killed them.

[Delores]

Thanks.

[Brezzin]

I know that Lifeline batteries can be equalized unlike most other AGM batteries. Has anybody ever done that through the Magnum?

httphttp://lifelinebatteries.com/201...agm-batteries/

[Alex AVI]

Originally Posted by 68 Overlander

Not sure if Airstream is doing this but many OEMs for the sake of liability are leaving the sniffers (LP and CO detectors) out of the disconnect switch. Might want to check that.

RANDY - I happened to be in midst using the AI all day today when I read above. So I double checked coz I was not sure myself. The CO detectors are standalone battery operated. The LPG detectors are in house battery Ckt 6 (along w/ fridge, tank sensors) which of course shuts off w/ battery disconnect.

Though slightly related to this idea of items left out of the disconnect switch - I saw on schematics that the lounge/sofa/bed motor, waste hose reel, & tank heating pads are not on disconnect switch. That last one is understandable, we do not want heating pads turned off from the disconnect switch. But the power sofa & hose reel ? Huh ? Am I missing something as to why this is ? Or have I misread the diagram ? But then I just confirmed power sofa & hose reel works with disconnect switch on/off.

[Titus]

On my 2013 the heater pads, lounge motor, radio, and solar are not routed through the disconnect switch. Instead they are fed from the battery to switchless breakers. All of my detectors go through the disconnect. Looks like they must roll the dice each year to decide which circuits to route around the disconnect. How is your hose reel fused if it does not go through the disconnect? Don't all 12V blade fuses get power through the disconnect?

[cazual6]

100% 12.6 >
090% 12.5
080% 12.42
070% 12.32
060% 12.2
050% 12.06
040% 11.90 - Yellow - Charge it
030% 11.75 - Yellow - Charge it
020% 11.58 - Yellow - Charge it
010% 11.31 - Red
000% 10.50 <

[Alex AVI]

Originally Posted by cazual6

100% 12.6 >
090% 12.5
080% 12.42
070% 12.32
060% 12.2
050% 12.06
040% 11.90 - Yellow - Charge it
030% 11.75 - Yellow - Charge it
020% 11.58 - Yellow - Charge it
010% 11.31 - Red
000% 10.50 <

CAZUAL6 - I like this. Thanks for posting. Printing it to put near nav station as constant remider

[68 Overlander]

Originally Posted by Alex AVI

CAZUAL6 - I like this. Thanks for posting. Printing it to put near nav station as constant remider

Just remember 12.2. It’s 50-60% SOC for almost all flooded or AGM batteries and should be your target don’t go below if possible. That said, it will not ruin your batteries to occasionally draw them lower. It will also lengthen their life to discharge them less if possible. It’s a balance of quality of Boondocking experience versus battery longevity. Some people are willing to shorten battery life and others are bent on making them last 8-10 years. Most important is to enjoy boondocking but you have to pay to play regardless.