Freedom 20 & AGM batteries?

Hi there,

Our stone age Heart Interface Freedom 20 inverter/charger has 'dip switches' allowing it to properly charge wet cell and gel cell batteries.

Do you think the gel cell settings would work with AGM batteries?

Thanks,

Murray

Here is what the Freedom 20 manual says:

Advanced AGM (Absorbed Glass Mat) Batteries
This battery is lead acid but maintenance-free. The performance is similar
to gel cell batteries. The charge parameters are similar to wet cell batteries.

The wet cell settings will be closer to the requirements of AGMs.

In this case I would suggest contacting the AGM mfgr for the specific voltage requirements of their batteries and compare that to the chargers output.
Hmmm, Heart is now Zantrex but it may still be worthwhile trying. Do you still have the manual. If not then maybe the manual is available online.

My Zantrex charges the AGM batts at 13.15 volts and they float at 12.75


I'm quite sure all three batt types should be set up specifically for standard lead acid, gel cell or AGM. So no I don't think so but the

The last word can be heard at Boat Electric in Seattle.

rochepoint said:

Here is what the Freedom 20 manual says:

Advanced AGM (Absorbed Glass Mat) Batteries
This battery is lead acid but maintenance-free. The performance is similar
to gel cell batteries. The charge parameters are similar to wet cell batteries.

Click to expand...

Our Freedom 20 is older, and the manual doesn't mention AGM batteries at all. What it does say is that the gel cell have, "Low internal resistance - the result of this is a higher battery voltage under load, which will result in better inverter performance on demanding high power loads. In addition this allows gel cell to accept a high rate of charge, a plus for rapid recharging".

This led me to believe the gel cell batteries would have a faster rate of charge, as programmed by the dip switches.

Am I wrong in thinking AGM batteries are able to accept a faster rate of charge than gel cell, and therefore a much faster charge rate than wet cells???

AGM can be charged faster , BUT suffer if charged at too high Voltage or overcharged.

A wet batt will need some distilled water , an agm scrapped if abused..

Our charger is old enough to only have two settings: lead-acid and gel. The manual says to use the lead-acid setting for AGMs.

-Chris

rochepoint said:

Here is what the Freedom 20 manual says:

Advanced AGM (Absorbed Glass Mat) Batteries
This battery is lead acid but maintenance-free. The performance is similar
to gel cell batteries. The charge parameters are similar to wet cell batteries.

Click to expand...

ranger42c said:

Our charger is old enough to only have two settings: lead-acid and gel. The manual says to use the lead-acid setting for AGMs.

-Chris

Click to expand...

All-righty-then, wet cell settings it will be. Thanks guys

So, to tie a nice tidy bow around my understanding of this (don't get your hopes up!) the AGM's fast charge rate is it's ability to absorb a charge faster, not as a function of the charger 'pushing' a higher load into it...right?

I just went through all of this.
See the thread here.... http://www.trawlerforum.com/forums/s4/batteries-11513.html

Long story short, the wet cell setting is very similar to AGM charging profiles. I bought Sears Die Hard Group 31 Marine AGM batteries. Don't laugh, they are made by Odyssey and some of the best batteries on Earth. Odyssey sells them for around $375...Sears sells them for $260. Odyssey will tell you straight up they are the exact same battery. I have a Charles 80 amp Charger. Anyway, I called both Charles and Odyssey to get the voltage rates for the charger and the charging profiles for the batteries. The wet cell setting on the Charles was within the parameters of the Odyssey batteries. I was trying to find the link for "approved" chargers for charging Odyssey batteries but I can't seem to find it. It tells you the brand of charger that is approved and what setting to put it on. The Charles was on there and they said to set it on "Wet cell". The girl at Odyssey said that amperage is very important. AGMs need a good blast of power to desulfate. A weak charger may not be up to that task.

One of the beauties of the Charles Charger and Odyssey batteries????......is that they are made right here in America and calling them and talking to an English speaking person that is friendly and EXTREMELY knowledgeable(and proud) of their product. All of the people I talked to at both companies were AWESOME!!!!

MurrayM said:

All-righty-then, wet cell settings it will be. Thanks guys

So, to tie a nice tidy bow around my understanding of this (don't get your hopes up!) the AGM's fast charge rate is it's ability to absorb a charge faster, not as a function of the charger 'pushing' a higher load into it...right?

Click to expand...

AGMs will accept a charge of a little higher voltage than flooded batteries. However, it is not good to charge them at the higher voltage charge of a gel cell battery. It should not harm them to charge them at flooded battery recommended voltage charge as it is close (but not over) to the AGM recommendation.

Thank you all for clearing some of the mists of confusion way down here at the bottom of the learning curve.

Moonstruck said:

AGMs will accept a charge of a little higher voltage than flooded batteries. However, it is not good to charge them at the higher voltage charge of a gel cell battery. It should not harm them to charge them at flooded battery recommended voltage charge as it is close (but not over) to the AGM recommendation.

Click to expand...

FWIW, our charger uses a lower absorption charge for gel (14.1v for gel versus 14.7 for wet cell and AGM in 12v systems). Float for both is 13.5v.

-Chris

lower absorption charge for gel (14.1v for gel versus 14.7 for wet cell and AGM in 12v systems).

The charge Voltage and the max amps pushed into the battery are different animals .

AS long as the voltage is at least one volt higher the battery will charge , the question is how long it will take , and that is usually determined by the Amperage provided

That is why a 135A or larger truck Alt with smart regulator gets the job done in lowest time.

For 24V systems 250 to 300A alts can be had from bus parts shops.