Confusion over AGM battery charging

[Deffheads]

Earlier this year I was forced to buy an AGM Odessy PC2250 leisure battery at considerable cost, as replacement gel battery was not available at all in any of the battery outlets.

I am concerned that the alternator on my 2006 Dethleffs A class 2.8JTD is not supplying the required voltage as it the standard fitment, I believe it should be charged at 14.4v to 15v.

How can I remedy this? as I want longevity from this battery. Also I have considered buying a dedicated AGM charger for when on EHU, is it possible to turn off the standard fitted one?

[mtravel]

No idea about the alternator.

Except the possible installation of a "booster" like the ones used on recent chassis equipped by an "intelligent alternator".

BTW, most motorhomes come equipped by AGM batteries, nobody care about voltage supplied by the alternator.

 

Charger: which make is the you original one ?

They usually have an internal dip switch(or similar) to address gel or liquid lead batteries.

(AGM is just a sort of fiberglass sponge absorbing liquid).

 

Max

[Deffheads]

Hi, it's an EBL 99 control panel, and I think AGM batteries were not available in 2006, only gel.

[mikefitz]

Charging from the engine via a dc to dc converter would be a suitable method . The Voltronic VCC 121230 is programmable (use AGM2 setting) for the correct charge voltage and is designed to interface to the EBL 99.

 

The AGM Odessy PC2250 requires a high charge voltage in the region of 14.6 to 14.8 volts with a long absorption time and a float voltage of 13.6. The standard mains charger in the EBL 99 has the option of GEL or normal lead acid via a switch on the RH side of the panel. This gives a 16 amp current charge at 14.3 volts for either setting with a float of 13.8 volts. All the setting switch does is change the absorption time from 8 hours for GEL to 1 hour for lead acid. The recommended absorption time for the Odessy battery is several hours so although the voltage is a bit low, using the GEL setting would seem to be the best option.

Measuring the voltage of a rested battery is one method the determine how well its charged. For this type of AGM battery around 13 volts indicates full charge, ( no loading, no charging, several hours rest).

Although the voltage from the EBL 99 is a little low, the slightly higher float will, to some extent, 'top up' the battery over a period of time.

 

My personal view for the design of a motorhome lead battery charging system, is that you need to have one of the chargers optimised for the battery, it wont matter too much if the others are lacking a bit in performance . Of course in an ideal situation all the chargers would be optimum design..

 

The EBL99 internal mains charger is supposed to be protected against excessive current draw taken by the battery and limit to 16 amps. How reliable this will be charging a 'hungry' AGM battery is a factor you may need to consider.

 

Mike

[Derek Uzzell]

The background to this is in the following earlier forum threads

 

https://forums.outandaboutlive.co.uk/forums/Motorhomes/Motorhome-Matters/Where-to-obtain-Exide-battery/52744/

 

https://forums.outandaboutlive.co.uk/forums/Motorhomes/Motorhome-Matters/ODYSSEY-PC2250-BATTERY-12V/52746/

 

https://forums.outandaboutlive.co.uk/forums/Motorhomes/Motorhome-Matters/Auxiliary-battery-charger-on-EBL99/53584/

 

and a technical manual for Odyssey batteries is here

 

https://www.odysseybattery.com/documents/US-ODY-TM-002_1214.pdf

 

Me, I’d select the gel setting on the present Schaudt charger and hope that this won’t cause any problems. Modifying the motorhome’s existing system in the belief that this might improve the longevity of the Odyssey battery would not be cheap and there would be no guarantee of a successful result.

 

It was known from Square One that fitting an AGM battery would not be best practice but (as Kevin has said) there was no realistic alternative at the time. If this is to be a real concern for Kevin, it’s likely to be less expensive to source an equivalent size gel battery now and fit that (and flog the AGM battery) rather than play about with extra chargers and worry about the motorhome’s alternator being suitable for the Odyssey battery.

[colin]

Our last AGM battery lasted for 8 years with a EBL99 set to 'Gel'.

[spirou]

I'd leave the EBL99 in place (in gel setting) but add a DC-DC booster. Especially if you tend to charge by driving. Possibly not worth if you don't. Votronic, Schaudt, Victron or any other with appropriate settings will do. They are not terribly expensive and should be relatively easy to fit into existing wiring. In this case you get at least one "correct" charging source. Changing the EBL would be more expensive if you couldn't sell the old one for a decent price. On the other hand, might be easiest if an updated 99 with AGM setting exits (no idea). In which case you'd just switch over. Those are the "easy" options. Adding a second charger in parallel could be less so.

[Robinhood]

The EBL 119 is effectively the EBL99 unit, but with AGM and Gel charging regimes, rather than Lead Acid and Gel.

 

I've already suggested on one of the other threads that the OP simply runs on the Gel setting, and sees how long the battery lasts (replacing with gel if and when it expires), but if this is unattractive, then another option is to have the existing EBL99 upgraded.

 

http://www.apuljackengineering.co.uk/repair_pages/agm_ebl_upgrade.html

 

An enquiry about cost may well reveal this is the simplest, most cost-effective solution to the concerns.

[Willum]

Deffheads - 2019-12-16 2:46 PM

 

Earlier this year I was forced to buy an AGM Odessy PC2250 leisure battery at considerable cost, as replacement gel battery was not available at all in any of the battery outlets.

I am concerned that the alternator on my 2006 Dethleffs A class 2.8JTD is not supplying the required voltage as it the standard fitment, I believe it should be charged at 14.4v to 15v.

How can I remedy this? as I want longevity from this battery. Also I have considered buying a dedicated AGM charger for when on EHU, is it possible to turn off the standard fitted one?

 

Forgive this if I've missed something but with the benefit of painful experience gained from the misfortune of trying to sort out charging problems on a new motorhome fitted with an AGM battery and supplied by a lying, toerag dealer, I'd offer the following:

Why use either a Gel, or AGM battery in the first place? A GOOD QUALITY lead acid will work just as well, be less prone to damage from charging system inadequacies and just as important as far as I'm concerned, considerably cheaper. A single 90/100 AH Varta/Yuasa/Bosch can be had for about £100. If treated correctly it will last a very long time.

A search through the forum for 'aandncaravans' responses regarding AGMs, or a look at their website pages at:

http://www.aandncaravanservices.co.uk/general-battery-faq.php

and the other related articles on it tells quite a story when you follow up their campaign for more honesty with battery descriptions and their thoughts on AGM batteries. Very few, if ANY, motorhome power units are equipped to charge AGMs. They fit them because they are either deceived by marketing woffle, or they can be left on a dealer's forecourt for a much longer time without being as badly affected as a lead acid battery left to go flat.

Will

ps yes, I am bitter about the dealer's business ethics.

[colin]

747Heavy - 2019-12-18 9:45 AM

 

Deffheads - 2019-12-16 2:46 PM

 

Earlier this year I was forced to buy an AGM Odessy PC2250 leisure battery at considerable cost, as replacement gel battery was not available at all in any of the battery outlets.

I am concerned that the alternator on my 2006 Dethleffs A class 2.8JTD is not supplying the required voltage as it the standard fitment, I believe it should be charged at 14.4v to 15v.

How can I remedy this? as I want longevity from this battery. Also I have considered buying a dedicated AGM charger for when on EHU, is it possible to turn off the standard fitted one?

 

Forgive this if I've missed something but with the benefit of painful experience gained from the misfortune of trying to sort out charging problems on a new motorhome fitted with an AGM battery and supplied by a lying, toerag dealer, I'd offer the following:

Why use either a Gel, or AGM battery in the first place? A GOOD QUALITY lead acid will work just as well, be less prone to damage from charging system inadequacies and just as important as far as I'm concerned, considerably cheaper. A single 90/100 AH Varta/Yuasa/Bosch can be had for about £100. If treated correctly it will last a very long time.

A search through the forum for 'aandncaravans' responses regarding AGMs, or a look at their website pages at:

http://www.aandncaravanservices.co.uk/general-battery-faq.php

and the other related articles on it tells quite a story when you follow up their campaign for more honesty with battery descriptions and their thoughts on AGM batteries. Very few, if ANY, motorhome power units are equipped to charge AGMs. They fit them because they are either deceived by marketing woffle, or they can be left on a dealer's forecourt for a much longer time without being as badly affected as a lead acid battery left to go flat.

Will

ps yes, I am bitter about the dealer's business ethics.

 

And yet as I posted above, we had two of Allen's pet hates as a battery, not just a AGM, but a Banner. 8 years of good service, have now replaced by couple of Varta's which haven't had much use, but are no big improvement.

[Willum]

............... apologies, don't know why my original came up twice but: (Now edited - Keithl)

 

In response to Colin: I agree, it's one of Allan's pet hates, but I believe with good reason.

 

I've certainly been the victim of flagrant mis-advertising of leisure batteries (Elecsol) and my experiences with AGM and Banner have not been good. Early failure for my first attempt at an AMG and poor demonstrated capacity for the Banner AGM.

The (expensive) Rolls AGMs in the first instance were quite hard worked (although not incorrectly) but failed after three years. The Banner AGM in a new motorhome was simply incapable of being charging correctly by the alternator (and the onboard charger was set incorrectly).

The excuses used ranged from an outright display of ignorance to the suggestion that the motorhome must be plugged in to a mains hookup on a regular basis. Oh really? What use is that if you are touring and/or free camping?

No offence to anyone intended and I'm certainly not trying to take this thread off topic but I will stick to what I said:

Lead acid batteries need no special treatment, the technology is tried and tested and continues to be developed. If it works OK, why look for an expensive, difficult to maintain solution, never really meant for the purpose for which it is being used?

Will

[Derek Uzzell]

If you refer to the links to earlier form threads that I provided above, it should be apparent why - in this instance - there was no realistic alternative to the Odyssey battery that happens to be AGM type.

[Willum]

Derek Uzzell - 2019-12-18 11:16 AM

 

If you refer to the links to earlier form threads that I provided above, it should be apparent why - in this instance - there was no realistic alternative to the Odyssey battery that happens to be AGM type.

 

It's a fair cop, Derek. Yep, I should have read the linked articles first. :$

I do still wonder at the rationale behind such a restrictive installation, though. My much loved, ancient Hymer was similar but I excused it on the grounds of age. :-)

Will