Lead acid & AGM/Gel in the same charging system

2

[2574]

...
Joined
29 Nov 2002
Messages
6,022
Visit site
Lead acid batteries have different charging requirements to Gel/AGM batteries. As I understand it the latter require a lower voltage charge as compared to the former. Does anyone know of a fancy alternator regulator which would enable a single alternator to charge the different battery types with the required correct (different) voltages? If not a regulator how else can this be achieved? Or should one never mix lead acid and Gel in the same system. I've heard that the whole system voltage should be reduced to suit the AGM/Gels - but that would mean that the lead acid's would never be fully charged?

Any thoughts would be appreciated.

rob

(ps - when I say mixed in one system I mean lead acid for the domestics and gel/agm for the engine start and bowthruster.)
 
Re: Lead acid & AGM/Gel in the same charging system

Check the charging requirement with the gel / AGM battery manufacturer, the one I looked into required a constant voltage charge of around 14.6 volt. So check out your selected battery for it's particular requirement, do not assumme a charge rate.

Brian
 
If your lead acid battery is of the sealed/no maintenance type then it has the same charging requirements as Gel/AGM

Even for other lead acid batteries you won't lose much by charging them as for Gel batteries - many people would recommend you to do that anyone to minimise gassing
 
Ive had dryfit tractionblocks for over a year!I let them charge by solar panel Monday i tried a pulse charger and it wouldent charge????? Put on my old ultra inexpensive normal charger and it charged to 14.6v!!!! stayed at 14.3v and is now 13.8v (just measured it.)

My second dryfit also charges to 14.xv and is now 13.4v my 95amp/hr car battery is at 11.9v i dont use much power yet,but i will when i find a fridge thats right!

I use the gels for SSB depth and telephone! Lead car battery for lighting.They sometimes fall to 10v when used at night.

Oh the question!! (wellits 10pm!) i charge them with the same solar panels and the same charger but each seperatly i change the charge as needed.
 
[ QUOTE ]
I've heard that the whole system voltage should be reduced to suit the AGM/Gels - but that would mean that the lead acid's would never be fully charged?


[/ QUOTE ]

1. You have heard correctly that the system should be set up for the Gel type batteries. It will still successfully charge both battery types.

2. The only drawback is that the charging will take slightly longer.

The reason for this is that you can sail a little closer to the wind in terms of the charging rate with a wet battery than a gel. You might lose a little more water by doing this, but this can be replaced. You can't take any risks with losing the electrolyte in a sealed wet or Gel battery. Hence the slightly lower charging voltage.
 
I am about to fit a Red Flash(AGM) as my starting battery & use my two other lead acid (sealed types) now both as domestics.I asked the supplier if this was a problem re charging of different batteries.He replied that the AGM can be considered as a lead acid battery & I have no need to change my charging regime either altenator or battery charger.He did say that the AGM charges more quickly as it has less resistance & as I still have the 1/2/both switch I should not charge the AGM for too long.
I do not ask about Gel batteries.
 
[ QUOTE ]
I am about to fit a Red Flash(AGM) as my starting battery & use my two other lead acid (sealed types) now both as domestics.I asked the supplier if this was a problem re charging of different batteries.He replied that the AGM can be considered as a lead acid battery & I have no need to change my charging regime either altenator or battery charger.He did say that the AGM charges more quickly as it has less resistance & as I still have the 1/2/both switch I should not charge the AGM for too long.
I do not ask about Gel batteries.

[/ QUOTE ]I was referring to the 'setup' of advanced mains and alternator regulators. What you are suggesting or saying that the dealer has told you doesn't contradict anything in my previous post.

All the batteries that we are discussing are Lead-Acid Batteries. The difference is in their plate design and the way that the electrolyte is held in place.
 
If you are using a smart alt. regulator then leave it set to gel, Have set mine to gel even though they are standard lead/acid, never had to top up and slightly longer to charge. /forums/images/graemlins/grin.gif
 
Last year i set my lidle pulse charger to normal car charge and it charged my gel batteries, this year day befor yesterday it just blinked on standby??

They were i think 12.X v and 12.8v one is less and just get chargedafter the other

i charged with a normal car battery charger on slow charge (13.8?? but the battery arrived at 14.8v is that a good voltage for gel????

why dosent my pulse charger work??it used to??
 
Re: Lead acid & AGM/Gel in the same charging system

Squadron marine GEL and AGM batteries are recommended to be charged at a constant 14.7 volt, so if anything you are going to overcharge a normal lead acid wet battery.
I still go back to original statement, check with your selected battery manufacturer, he is the only one who can say how it should be charged.

Brian
 
14.8v. is too high for Gel: if you have them in the set up you should restrict the voltage to 14.2 and the charge rate to a 10 hour rate, i.e. nominal capacity divided by 10. e.g. 400AH charge at 40Amps maximum.

As previous poster says, AGM will charge more rapidly, but are also no-maintenance and leak proof as in Gel. They can take higher rates of discharge.

We use a small lead acid for engine start and Gel for all other services. Chargers and alternator regulator set up for Gel accordingly.
 
Going to disagree with most of the above. You should NOT mix gel with either AGM or wet cells. They have different charge requirements including float voltage.

You can probably get away with mixing AGM and wet as they are much closer but personally I would pick one type of battery and standardize on that for all my needs.
 
You must log in or register to reply here.

Other threads that may be of interest

N
Volvo Penta Alarm Module/Alternator Issues
Replies
1
Views
137
superheat6k
superheat6k
Baggywrinkle
Test run of the Lithium system that has been sitting in my cellar for most of this year.
Replies
7
Views
377
jakew009
J

Share this page

Top