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Topic: Batterys (Read 646 times) previous topic - next topic

Batterys

Hi all,
Has any one changed their D8 lead acid house batterys to AGM's,
Did you have any problems with them, If so, What problems,
As in the Diesel motors Alternator would not charge them, Old technology, Etc, Etc,
Or cooked them, ?????????

Thanks, Brian,
Cheers, Brian,
1989 Foretravel Grand Villa, 36 foot ORED, 300 HP Catapillar and Four Speed Allison Auto,
Right Hand drive, two Mid doors, Makes a good flow thru ventilation in hot weather,
Located in Melbourne, Australia,  The Land Down Under,
Honda Blackbird, 1100XX.    2002 Gemini 105 MC Catamaran,

Re: Batterys

Reply #1 –
Mine had AGMs when I bought it and I've replaced them all with the same during my ownership.  No problems.  Need to make sure your battery charging system is compatible.

Rich
Rich and Peggy Bowman
2002 U270 3610 WTFS, build #5939--"Freedom"
2022 Jeep Grand Cherokee Summit 4xe
SMI AirForceOne brake system
PakCanoe 15

Re: Batterys

Reply #2 –
Quote from: Mr B3 –
Hi all,
Has any one changed their D8 lead acid house batterys to AGM's,
Did you have any problems with them, If so, What problems,
As in the Diesel motors Alternator would not charge them, Old technology, Etc, Etc,
Or cooked them, ?????????

Thanks, Brian,


Brian, AGM batteries are lead acid batteries. Just pull the 8D and replace with flooded cell technology with the Absorbent Glass Mat technology.  The only thing that might cause trouble is if your inverter/charger uses a true equalizing charge, that you'll need to remove from the programming.  Other than that all will be fine.

FWIW I'm running an AGM battery in my 1968 Siata with its mechanical regulator and generator.  No problems even after a 6 hour drive.
1992 Foretravel Grand Villa
U225 SBID Build No. 4134
1986 Rockwood Driftwood
1968 S.I.A.T.A. Spring
1962 Studebaker Lark
1986 Honda VF700C
1983 Honda VF750C
Charlie, the Dog was broken out of jail 24 Oct 2023
N1RPN
AA1OH (H)e who must be obeyed.

Re: Batterys

Reply #3 –
Quote from: Rich Bowman –
Mine had AGMs when I bought it and I've replaced them all with the same during my ownership.  No problems.  Need to make sure your battery charging system is compatible.

Rich

Thats what worries me, My 1989 alternator on my 300 HP Cat diesel, Might not be compatible for AGM batterys,
Cheers, Brian,
1989 Foretravel Grand Villa, 36 foot ORED, 300 HP Catapillar and Four Speed Allison Auto,
Right Hand drive, two Mid doors, Makes a good flow thru ventilation in hot weather,
Located in Melbourne, Australia,  The Land Down Under,
Honda Blackbird, 1100XX.    2002 Gemini 105 MC Catamaran,

Re: Batterys

Reply #4 –
Charging algorithms for AGM and wet cell are very similar.

You may be concerned about a non-problem.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Batterys

Reply #5 –
Don't think there will be an issue with AGM house batteries--I have been told by many sources that AGM and LA bats have similar charging profiles.  However, Li batteries are a whole different animal.  My latest experience with bat replacement was last Fall when we bought our 2015 IH.  I now suspect both house and chassis bats were original, and they were gel-type. I mis-read the born-on dates and while dealer stated: "bats were fine," they weren't!  But to the point--when discovered, dealer declared that the chassis and house bats should match, so I eventually end up with new AGM bats for both house and chassis.  Have no idea if it's true but it does seem reasonable that charging profiles for both battery banks should be the same or similar. 
Old Scout
2015 IH45
New Braunfels Tx

Re: Batterys

Reply #6 –
Brian,

From what I've read on this Forum, more batteries are ruined by OVER-charging than by UNDER-charging.  If you are really concerned about using your 1989 alternator to charge new AGM batteries, you could check the alternator with your multimeter.  Run alternator output into any 12V battery known to be in good physical condition.  When the battery reaches full charge, check the "float voltage" being output by the alternator.  If it is too high, you may want to consider fitting a new alternator, just to be safe.

Text taken from a Battery University document, with links below:

"As with all gelled and sealed units, AGM batteries are sensitive to overcharging. A charge to 2.40V/cell (and higher) is fine; however, the float charge should be reduced to between 2.25 and 2.30V/cell (summer temperatures may require lower voltages). Automotive charging systems for flooded lead acid often have a fixed float voltage setting of 14.40V (2.40V/cell); a direct replacement with a sealed unit could overcharge the battery on a long drive."

BU-201a: Absorbent Glass Mat (AGM) - Battery University

BU-403: Charging Lead Acid - Battery University

1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Batterys

Reply #7 –
Part of the equation on alternator potentially overcharging is how many hours per year the alternator is actually charging.

14 VDC occasionally is very different than 14 VDC if driving 20,000 miles a year.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Batterys

Reply #8 –
That's why I installed the twin digital voltmeters on the dash where I can instantly read them while driving. Watching the voltages while driving is very useful in more than a dozen different ways. When at a campsite, it keeps track of battery voltages, condition with only a glance needed. Most radios, ECUs are rated at 13.8 volts while underway. Also the reason I went with the Progressive Dynamics converter as it's very stable at 13.2 volts while the coach is on shore power.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: Batterys

Reply #9 –
Interesting comments/information about over-charging AGMs.  My Outback inverter/chargers have a battery temp sensor mounted to the house bat bank, which I understand, derates the charger function if a specific battery temp is attained.  Would this capability help deter over-charging, assuming higher temps are associated with over-charging?
Old Scout
2015 IH45
New Braunfels Tx

Re: Batterys

Reply #10 –
Quote from: OldScout –
Interesting comments/information about over-charging AGMs.  My Outback inverter/chargers have a battery temp sensor mounted to the house bat bank, which I understand, derates the charger function if a specific battery temp is attained.  Would this capability help deter over-charging, assuming higher temps are associated with over-charging?


Yes, battery mounted temp sensor will help with over AND under charging.  The lower the temperature, the higher the needed voltage.

BTW there are "smart regulators" available.  Been using one on our sailboats for the last decade. IMO much more important on a boat that is covering miles, as the engine is on 8-10 hours a day for three weeks (Galveston Bay to the Bahamas).

Balmar Voltage Regulation Technology - BalmarBalmar
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Batterys

Reply #11 –
Someone before me put in the two voltmeters which awesome but I would also
like an ammeter on the alternator. I remember when cars had an ammeter and then
they changed them with a voltmeter. I prefered the ammeter as it gives me more in
information.
Peter and Frieda Morin
1999 36ft. U320 Foretravel
Build # 5436
1998 Suzuki Sidekick Sport

Re: Batterys

Reply #12 –
Quote from: OldScout –
My Outback inverter/chargers have a battery temp sensor mounted to the house bat bank, which I understand, derates the charger function if a specific battery temp is attained.  Would this capability help deter over-charging, assuming higher temps are associated with over-charging?
Most modern inverter/chargers include (battery) temperature compensated charging as a standard or optional feature.

However, Brian's original question concerned the OEM alternator's ability to properly charge AGM batteries.  I am not aware of any alternators with internal voltage regulators that compensate for battery temperature.

NOTE:  After further Googling, I have learned that some factory installed alternators DO have a temperature compensation curve in the voltage regulator which responds to ambient (under hood) air temperature.

And, as Brett stated, an external "smart" voltage regulator could also be employed with any alternator to serve this purpose.

Lots of ways to skin a cat...

1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Batterys

Reply #13 –
Quote from: oldguy –
I remember when cars had an ammeter and then they changed them with a voltmeter. I preferred the ammeter...
IMO it is simple - voltmeters are less expensive, if you get one at all.  Most cars today it's just a LED or a little icon on the dash.  It's all about the bottom line.

See below for further justification:

Which is better for monitoring a vehicle's electrical system - a Voltmeter...

1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Batterys

Reply #14 –
I agree Chuck it's about the bottom line but I can get a lot more information from 
an ammeter. I was talking to a friend yesterday and we both miss them. I might put
one in the coach. When I'm charging the coach batteries it is the ammeter I look at
to see if they are charged.
Peter and Frieda Morin
1999 36ft. U320 Foretravel
Build # 5436
1998 Suzuki Sidekick Sport

Re: Batterys

Reply #15 –
Quote from: wolfe10 –

Yes, battery mounted temp sensor will help with over AND under charging.  The lower the temperature, the higher the needed voltage.

BTW there are "smart regulators" available.  Been using one on our sailboats for the last decade. IMO much more important on a boat that is covering miles, as the engine is on 8-10 hours a day for three weeks (Galveston Bay to the Bahamas).

Balmar Voltage Regulation Technology - BalmarBalmar

Try 20 hours and 24 hours and 23 hours straight, coming down the Tasman Sea and Bass Strait on my way home,
Took over six weeks to travel approx 800 Nmiles, hiding from bad weather on the way down the coast,
I am well and truly over 4 and 6 metre waves on the nose,

My new AGMs I had in the boat went over the side, They were dead,  It might have been the alternator from 2003 on the diesel that killed them,
The lead acid batterys I never had a problem with in 3000 Nmiles,  Including running the diesel for 4 days straight, 24/7,  In the Coral Sea,
My Solar Panel controllers have anti every thing, They wont over charge, reverse charge,  Etc Etc,


Cheers, Brian,
1989 Foretravel Grand Villa, 36 foot ORED, 300 HP Catapillar and Four Speed Allison Auto,
Right Hand drive, two Mid doors, Makes a good flow thru ventilation in hot weather,
Located in Melbourne, Australia,  The Land Down Under,
Honda Blackbird, 1100XX.    2002 Gemini 105 MC Catamaran,
 

Re: Batterys

Reply #16 –
Quote from: Mr B3 –
My new AGMs I had in the boat went over the side, They were dead,  It might have been the alternator from 2003 on the diesel that killed them,
The lead acid battery's I never had a problem with in 3000 Nmiles,  Including running the diesel for 4 days straight, 24/7,  In the Coral Sea,
My Solar Panel controllers have anti every thing, They won't over charge, reverse charge,  Etc Etc,

Flooded cell batteries can always be topped up with distilled water.  Absorbent Glass Mat batteries are intended to run electrolyte starved to limit internal corrosion from being over charged.  In theory you can't overcharge an AGM design.  In reality, the internal catalyst that turns the hydrogen and oxygen gasses back into water becomes overwhelmed by the quantity of gas generated when being overcharged at 14.4V and the pressure regulation valves vent the gasses to the atmosphere.

14.4V up to about 80% state of charge is just fine, afterwards, not so much so.

The mechanical voltage regulator in the 1968 Siata is adjusted to 13.8V.
1992 Foretravel Grand Villa
U225 SBID Build No. 4134
1986 Rockwood Driftwood
1968 S.I.A.T.A. Spring
1962 Studebaker Lark
1986 Honda VF700C
1983 Honda VF750C
Charlie, the Dog was broken out of jail 24 Oct 2023
N1RPN
AA1OH (H)e who must be obeyed.