AGM battery charging and PL20 advice

Submitted: Thursday, May 22, 2008 at 13:11
ThreadID: 57885 Views:6422 Replies:6 FollowUps:0
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Good afternoon,
I was hoping that someone may be able to answer a few questions for me.

I have just changed over my wet cell batteries in my camper trailer to Remco agm (2 x 100amp) and would like to know the following.
I have both a Ctek 7 amp charger and a Xantrex truecharge 20i. From memory I have read somwhere that the Ctek may not be suitable for leaving on a float chartge with AGM's for an extended period of time?
Has anyone heard of this? Should AGMs be left on float for months or should they be charged and then removed from the charger?
On the the truecharge 20 there are several settings eg wet, gel and temp settings. Is anyone familar with this charger and which settings would you use when charging the remco batteries.
I'm not sure if the agms should be charged as wet or gel?
Finally I have a PL20 which I assume will need to be reconfigured for the AGM batteries if you are familar with the Pl20 which settings would you reccomend to charge these batteries?


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Reply By: Redeye - Thursday, May 22, 2008 at 14:27

Thursday, May 22, 2008 at 14:27

All batteries should be floated in preference to leaving sitting. Even new car batteries should be recharged every 3 months when on the shelf (this may never happen in real life).

For your settings on the true charge I would recommend Battery Type = Gel and Temperature to Hot. This will prevent the cells from overcharging and venting.

As for the Ctec charger I have no knowledge of these.

Good luck

AnswerID: 305281

Reply By: Member - Mark E (VIC) - Thursday, May 22, 2008 at 14:50

Thursday, May 22, 2008 at 14:50
The CTEK will be fine for float charging.

Advice I received from someone infinitely more knowlegable than I suggests that it isn't really necessary to float charge an AGM battery, due to the very slow no load loss...I think it is something like 1% per month.

I have an AGM in the car and one in the camper and I don't bother to float charge the camper...seems like a wast of energy to me. I do, however stick the charger on it once every couple of months and it shows the fully charged indication after just a few minutes.

The one in the car gets munh more use and I do top this one up fairly regularly whilst near 240v power.


AnswerID: 305285

Reply By: Sand Man (SA) - Thursday, May 22, 2008 at 15:55

Thursday, May 22, 2008 at 15:55

It's not factual that the CTEK charger cannot be left on a float charge with AGM's for an extended period of time.

The CTEK is arguably the best battery charger around.

One point however. An AGM battery will not lose much of a charge when sitting idle for a period of time and it is probably false economy to leave the batteries on float charge any longer than necessary, once they have reached full capacity.

Not to say you can't do it without damage to the battery or charger, but there is no real need that I can think of.



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AnswerID: 305300

Reply By: Member -Dodger - Thursday, May 22, 2008 at 16:36

Thursday, May 22, 2008 at 16:36
Treat the AGM batteries as you would your wet cell batteries. In other words leave your set up as is. The PL20 will charge these batteries quite well there really is no need to change anything.
AGM stands for absorbed glass matt batteries, that is they have electrolyte in them the same as a flooded battery only it is absorbed in the glass matt. The only real difference is that the AGM batteries accept a charge much more easily and will therefore charge up quicker.
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AnswerID: 305308

Reply By: richor - Thursday, May 22, 2008 at 18:37

Thursday, May 22, 2008 at 18:37
I have two 100 Ah AGM batteries and I set my PL20 up as follows : -

I use Prog 4
BMAX = 14.5
EMAX = 15.0
ETIM = 0 (this turns equalisation off)
FLTV = 13.5
CHRG = 20
BFRQ = 15

I find this works well.

AnswerID: 305331

Reply By: Member - Phil G (SA) - Thursday, May 29, 2008 at 23:02

Thursday, May 29, 2008 at 23:02
You can get (hopefully) all the info about charging Remco batteries here:
AnswerID: 306651

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