Shocking Discovery. . .

[RJ]

 Noticed that the house system's voltage dropped dramatically a couple days after arriving in Cheney, WA, after visiting my daughter and her family in Kelowna, BC.

I also noticed that the chassis voltage was also down.  So I  pulled the chassis batteries (which were new in March 2016) and found they were both at 10.5 volts.  However, they both bounced back to normal after a few hours on the charger.  I'll check them again in the morning to see if they're holding the charge, as they're sitting in the garage (on cardboard, btw.)

After getting the chassis batteries out and on the charger, I tackled the house set.  After removing the protective box, the photo below is what I found.  I have NO idea what happened, and am curious if my fellow busnuts have not only ideas as to what happened, but suggestions on how to prevent it in the future.

This is (or was) a Sonnenschein Prevailer dryfit DF8D gel cell battery.

[TomC]

7 years old, low on water. Lucky it didn't do any real damage. Good Luck, TomC

[RJ]

7 years old, low on water. Lucky it didn't do any real damage. Good Luck, TomC

This is (was) a maintenance-free gel cell battery, Tom. 

Somebody will ask, so here is info and a photo of my on-board charger:

http://www.iotaengineering.com/pplib/dls2740spec.pdf

[chessie4905]

Another gel battery problem. Overheat runaway? Do you have any type of temp monitor/ control?

[Sam 4106]

You mention removing a protective box, does the box allow air circulation to keep the batteries from overheating?
Good luck, Sam

[luvrbus]

 I don't believe you use a Vanner to equalize Gel Cell or AGM deep cycle batteries if the LifeLine guy knew what he talking about.Gel's are good batteries but real picky on the charging 

[eagle19952]

i have been told by DEKA and xantrex not to EQ AGM's and gel's. is that what happened ?

iirc 13.8v is max charge on mine.(AGM's)

[Jon]

It should be clear that the equalizing is not maintaining a proper relationship between a 12 and 24 volt circuit via the use of an equalizer, but the equalizing to be avoided is a high voltage battery charge to bring some life back into older batteries. An equalization charge is usually in excess of 15 volts and that voltage will ruin gel cell batteries for sure. So will constant charging with any inverter or charger not capable of going through the three stages of charging and whose charging currents are not set for the specific battery type.

[luvrbus]

He has a 24v system and the Iota 27-40 is a 2 stage converter/charger he needs the IQ series with 3 stages I don't think Iota makes that converter/charger anylonger 

[bigred]

Could the inverters being set on the wrong type of battery have done this??

[luvrbus]

Looking at the photo on another board he has the fast charge plug in the converter that changes the charging rate on his converter from 27.2 to 28.4 volts 

[Lin]

On my former bus, we had a bank of AGM UPS batteries that may have had a similar problem. but it was the posts that rotted out.  We also had an Iota charger, not converter though. It was supposedly a three stage charger.  I do not know for sure what happened, but a battery man I spoke to suggested that the charger was at fault.  My house loads were directly connected to the batteries, and I believed the charger would just make up for usage when I turned lights, etc on.  He said that some 3-stage chargers will interpret that load as the battery needing to charged and go into bulk mode.  Not only that, but some of those chargers had a minimum timed bulk charge once the process started.  Therefore, I could have been turning some lights on, which put the charger into bulk mode and let it stay there for an hour even when the load was turned off.

It's hard to know for sure in such situations without an almost expert knowledge of the electronics of a particular unit.

[luvrbus]

Drawing from a battery bank and using a charger has long been a practice in the marine world.I used that setup in the Eagle and it was never a problem 

[Lin]

Well, I still do it too, but the inverter/charger I am using is supposed to be much smarter.

[luvrbus]

Well, I still do it too, but the inverter/charger I am using is supposed to be much smarter.

Lin I had a dumb @$# Marinco charger and it worked for 10 years till it started frying batteries towards the end of it's life