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Topic: Alternator charging both sets of Batteries (Read 982 times) previous topic - next topic

Alternator charging both sets of Batteries

The specification sheet at beamalarm.com for the 1994 U225 calls for "Engine Batteries -1600 CCA Gel Cell" and "Coach Battery (1) Gel Cell 408 Reserve minutes", but came equipped (when I obtained) with 2 Optima "AGM" starting batteries (replaced with Interstate wet cell 34s) and 2 Coach 8D gel deep cycle batteries.  To cold to go out and pull out my build sheet and see what the real orginial factory equipment was.

Now I have a question!!  I understand that the alternators can be set up for charging at different rates just like a converter/charger can be.  Now if it is set up for the charging the Optimas "AGM" and AGM house batteries and you end up switching out with wet cell starting batteries and Gel cell house batteries, is the alternator going to kill those batteries.  Do you have to switch something to make them charge properly so they will last, like you would switch the converter/charger?  And in my case, with Gel 8D house batteries and wet cell chassis batteries, is it ok to use the Trik-L-Charge, or with the charge from my Progressive Dynamics PD9270  set up for Gel batteries kill the wet cells?
1994 U225
build #4514

Re: Alternator charging both sets of Batteries

Reply #1 –
Quote from: PatC –
Now I have a question!!  I understand that the alternators can be set up for charging at different rates just like a converter/charger can be.  Now if it is set up for the charging the Optimas "AGM" and AGM house batteries and you end up switching out with wet cell starting batteries and Gel cell house batteries, is the alternator going to kill those batteries.  Do you have to switch something to make them charge properly so they will last, like you would switch the converter/charger?  And in my case, with Gel 8D house batteries and wet cell chassis batteries, is it ok to use the Trik-L-Charge, or with the charge from my Progressive Dynamics PD9270  set up for Gel batteries kill the wet cells?


While you CAN have a "smart regulator" (we do on the sailboat:  http://www.northeastmarineelectronics.com/xantrexxar-12alternatorreg84-2006-01.aspx) they are very rare on vehicles.

This is one of the reasons that I threw out my diode-based battery isolator and replaced it with a simple marine ON-OFF 360 amp continuous duty switch.  Alternator output and chassis battery are wired to one side of the switch.  House battery to the other side of the switch.

So, switch off, engine running, engine battery charged. Switch on, both batteries charged.  If I am driving from a CG with power to a CG with power, it is crazy to pay diesel to push the alternator harder to OVERcharge the house batteries all day.

This set up also allows combining of both battery banks with the turn of the switch to ON.  Switch is located on the wall under the foot of the bed where it is easy to access and where all electrical connections could be made without altering any of them-- just pulled wires from behind drivers rear wheel into the "electrical compartment".

While two different battery technologies on the same charger are not ideal, in the real world, it WILL work.  We are talking about acceptable vs ideal. It is really the float level (voltage 24/7) that needs to be more tailored to the battery technology than short time charging voltage.  And wet cell and AGM's are much closer in their ideal charging voltages than are either combined with gel.

Brett
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: Alternator charging both sets of Batteries

Reply #2 –
Quote from: wolfe10 –
While two different battery technologies on the same charger are not ideal, in the real world, it WILL work.  We are talking about acceptable vs ideal. It is really the float level (voltage 24/7) that needs to be more tailored to the battery technology than short time charging voltage.  And wet cell and AGM's are much closer in their ideal charging voltages than are either combined with gel.

Brett
Then I take it that with my two Gel 8D house batteries, I am best to have the Progressive Dynamics 9270 converter  set up for the Gel batteries and not worry about the wet cell chassis batteries?  The PD converter just uses a jumper shunt to set it up for the Gel type batteries.  When I eventally get rid of the Gel batteries and switch to other type batteries, I can just pull the jumper off.
1994 U225
build #4514

Re: Alternator charging both sets of Batteries

Reply #3 –
Yes, if you have Gel batteries set your charger, converter or inverter/charger to GEL. 

Gel batteries float voltage is above that for wet cells, so keep an eye on water level in the chassis batteries.

Brett
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: Alternator charging both sets of Batteries

Reply #4 –
Well, I can't seem to find the Topic I thought was discussed in the past, but this one is somewhat relevant.  Pat C asked,
Quote from: PatC –
I understand that the alternators can be set up for charging at different rates just like a converter/charger can be.  Now if it is set up for the charging the Optimas "AGM" and AGM house batteries and you end up switching out with wet cell starting batteries and Gel cell house batteries, is the alternator going to kill those batteries.  Do you have to switch something to make them charge properly so they will last, like you would switch the converter/charger?  And in my case, with Gel 8D house batteries and wet cell chassis batteries, is it ok to use the Trik-L-Charge, or with the charge from my Progressive Dynamics PD9270  set up for Gel batteries kill the wet cells?
I'd like to know if the Leece-Neville 130 amp alternator has an adjustment for its voltage output.
Peter & Beth Martin
No Forrest? What have you done?
MC# 15890 until Dec 2016; FMCA #F329677
Cincinnati, OH

Re: Alternator charging both sets of Batteries

Reply #5 –
Leece-Neville sells both interchangeable and fixed voltage regulators.  They are easy to change, or have an alternator shop do it.  Of course, the critical voltage is at the battery bank, not at the alternator.
Regards,
Brett

'99 42' Foretravel Xtreme
'14 Brown Motorsports Stacker
'05 Chevy SSR
'02 BMW R1150R

Re: Alternator charging both sets of Batteries

Reply #6 –
If you can find a good alternator shop have them rebuild yours to a higher amp rating ,usually less than $100. Had mine built to 180 amp and it tested at 198 amp.
Gary & Sharon Karnes
1999 295 WTFE 3600

Re: Alternator charging both sets of Batteries

Reply #7 –
If you decide to change the voltage regulator on your alternator I suggest that you get one that is adjustable via a potentiometer or pot.  This will allow you to set the charging voltage exactly as you prefer.
Regards,
JON TWORK KB8RSA
Full Time RVer (10+ Years) & Dedicated Boondocker
Retired, Unemployed, Homeless Transients
1996 Foretravel U270-36 w/24' Timberwolf Trailer
I firmly believe that tomorrow holds the possibility for new technologies, astounding discoveries, and a reprieve from my remaining obligations.
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