Interesting discovery while topping off water in house batteries

[Rich W.]

I add water to my batteries more or less monthly unless I’m not plugged in and using solar a lot which causes more charge cycles in which case I check them more often. Anyway Im home how so I’m plugged in which miminizes house battery use so reduces the need, so….monthly.

So I did the usual with my hand bulb pump adding water to the six house batteries through my watering system from a gallon jug of distilled. As always I pumped until they wouldn't take any more, then put everything away. But I also noticed some corrosion on some of the connections so I decided it was time for a little battery maintenance.

But when I pulled out the tray I could hear water running down inside the batteries. Finding this a bit curious, I got out the pump and tried adding more water. They took about another 1.5 pints! So my little discovery is that something (air pockets?) is preventing the batteries from fully filling when I go through my normal routine, and it seems the batteries need a little agitation to cause the water to settle in all the way allowing me to fully fill them.

Or am I now over-filling them? Seems odd that the water would remain in the top portion of the batteries with a void below that point and not allow the addition of more water. Ideas?

 

[B52Bombardier1]

If your batteries are "out-gassing" due to excessive charging, pockets of perhaps this hydrogen sulfide gas could be trapped between the plates.

Rick

 

[Neal]

I just got done putting a half gallon in mine using the flow-rite system. I put what I had left in the other day, I do this probably quarterly. I'm about to start an equalization. Have you been doing those as well? I do it every 6 months.

 

[Rich W.]

no I dont have a decent charger. Its on my list and I should probably stop procrastinating and just buy something but locally prices are high and selection is low. I’d like to find a good used power supply which would be more useful than a basic battery charger.

 

[Neal]

How To - Equalization of your Lead Acid RV batteries

If you have lead acid batteries, are you performing equalizations? I've heard mixed reports on how often to do it, I personally do mine every six months. I also have the pro-fill battery watering system to help keep the water maintained which I check every 1-2 months. Here is a little video...

rvforums.com

 

[Rich W.]

How To - Equalization of your Lead Acid RV batteries

If you have lead acid batteries, are you performing equalizations? I've heard mixed reports on how often to do it, I personally do mine every six months. I also have the pro-fill battery watering system to help keep the water maintained which I check every 1-2 months. Here is a little video...

rvforums.com

I’ll check that out. Thanks.

 

[Kevin D Pem]

I’ll check that out. Thanks.

Once the batteries are fully charged, you can use the solar system to equalize if it has the option. And yes I would guess hydrogen bubbles is the issue.

When the battery terminals start to corroded it is time to think about replacement.

 

[Rich W.]

These batteries were freebies, installed by La Mesa when I bought the coach without being asked. I went there to buy it “as is” but they insisted on spending a full eight hours servicing and cleaning everything inside and out including a rack of new batteries. When I replace them it will be with bigger AGMs but I’m pretty sure I can get a couple more years out of these.

 

[Rich W.]

I had no idea it was so simple or that the magnum remote would do this. Thanks @Neal !

 

[Rich W.]

Interestingly this over charges the chassis batteries as well (at least on my rig) so one would be well advised (I think….?) to turn off the chassis batteries while equalizing the house batteries. My chassis batteries were cooking along at 15.7 before I noticed and shut them off, where the house battery bank is equalizing properly (I hope) at 14.9. According to a chart published in RV Tech the eq charge for 12v should be 15.5. I’m guessing that this unit was set up to eq at 14.9 which to my knowledge is also the bulk charge rate.

 

[Neal]

Hmmm, the magnum only controls the inverter which connects to house batteries. I'm not sure how it's related to chassis battery charging. However, is it really bad to also equalize the chassis batteries? May be a good thing in disguise. What may be "cooking" your chassis batteries is a known issue which is the solar panel for the chassis batteries has no controller and some have noted the overcharge conditions it causes. @redbaron I think was the first to raise this issue. I tend to equalize at night when demands are lower in the CG and on my rig, not in the heat of the day.

 

[Rich W.]

The little (10w?) chassis battery solar panel is long gone. Over-charging my chassis batteries has never occurred before and only happened when I initiated the hoise battery equalizing. It may not be a bad thing, but it‘s unnecessary and seems like it has to stress the batteries. Why the inverter/charger is “equalizing” both is a mystery to me to, but it can’t happen with the chassis batteries off, so until I figure it out or determine that is ok that’s going to be my approach.

 

[Joe Hogan]

In many new RVs they have a Bi-Directional Relay that allows current to charge the chassis battery from the house battery charging circuit. Hence the term Bi in the name

“
00-00362-100

Intellitec’s Bi-Directional Isolator Relay Delay (BIRD) offers a new approach to charging batteries in an RV application. Unlike prior systems that only allowed charging the RV battery from the engine’s alternator, the Bi-Directional Isolator Relay Delay charges both batteries when either one is being charged. When the coach is being driven, both batteries will be charged from the engine’s alternator. When the coach is plugged into shore power, both batteries will be charged from the converter. If neither battery is being charged, the batteries are fully isolated. The controller also senses heavy loads on either battery to prevent the wrong battery from being inadvertently discharged.”

 

[Rich W.]

In many new RVs they have a Bi-Directional Relay that allows current to charge the chassis battery from the house battery charging circuit. Jensen the term Bi in the name

“
00-00362-100

Intellitec’s Bi-Directional Isolator Relay Delay (BIRD) offers a new approach to charging batteries in an RV application. Unlike prior systems that only allowed charging the RV battery from the engine’s alternator, the Bi-Directional Isolator Relay Delay charges both batteries when either one is being charged. When the coach is being driven, both batteries will be charged from the engine’s alternator. When the coach is plugged into shore power, both batteries will be charged from the converter. If neither battery is being charged, the batteries are fully isolated. The controller also senses heavy loads on either battery to prevent the wrong battery from being inadvertently discharged.”

Yes I believe this to be the case. When charging, all batteries get power. When using the house batteries with shore power not connected, the chassis batteries are isolated. So to prevent 15.5v from over charging my chassis batts while equalizing the house bank, I turned off the chassis batts. The things you learn here…... The chassis batts are at 12.6v at rest - 100%; condition of the house bank remains to be seen. Guess I’ll know in a couple hours.

 

[Neal]

Not convinced but still ears wide open. We have to dissimilar battery banks, completely different batteries in each area, who and how is the charge current being controlled to ensure it's appropriate for the type and size of the battery bank?

 

[Rich W.]

Well two 12’s in parallel for the chassis, or three groups of two 6s in series for house, they’re still both 12v battery banks of LA batteries and it would seem the same bulk, absorb, and float voltages would apply, with amperage determining how long it takes to charge each bank. How that magic happens to me is a bit of a mystery beyond my assumption that it’s all regulated by various electronic adjuncts - BIM, BIRD, relays, ….etc. Right? I guess I should be more up to speed on this but as long as its all working, I have other things to concentrate on.

 

[Kevin D Pem]

Well two 12’s in parallel for the chassis, or three groups of two 6s in series for house, they’re still both 12v battery banks of LA batteries and it would seem the same bulk, absorb, and float voltages would apply, with amperage determining how long it takes to charge each bank. How that magic happens to me is a bit of a mystery beyond my assumption that it’s all regulated by various electronic adjuncts - BIM, BIRD, relays, ….etc. Right? I guess I should be more up to speed on this but as long as its all working, I have other things to concentrate on.

So your saying that ahr is programmed for the two banks separately?

 

[Kevin D Pem]

So your saying that ahr is programmed for the two banks separately?

Or are you saying it is a time thing and capacity is not an issue?

 

[Rich W.]

Or are you saying it is a time thing and capacity is not an issue?

not sure I understand the question(s), but I am surmising that the chassis batteries hit their eq charge of 15.5 first (rather quickly actually) because there are just two of them and they are fairly new - less than a year old. At that point I shut them off (started worrying about them), and let the house bank “equalize”. That took several more hours. Once everything was at rest both sets showed 100%, so life is good.

so….charging/equalizing is/was a time thing, and capacity is good (100%) so not an issue? I’m a little slow sometimes, so if I still don’t get it, just let me know.

 

[Joe Hogan]

Here is some useful data on Equalizing. (as I quietly mumble thank god for LiFePo)

RV Tech Library - Equalizing Batteries

www.rvtechlibrary.com

BU-404: What is Equalizing Charge?

BU meta description needed...

batteryuniversity.com