About Victron chargers and AGM batteries

[hey-hey-my-my]

Hi all,

I've just purchased a Victron 7 stage 30A charger : Victron Blue Smart IP22 Bluetooth Battery Charger - 12V 30A, 3 outputs - https://www.12voltplanet.co.uk/victron-blue-power-ip22-7-stage-adaptive-battery-charger-12v-30a-3-output-uk-plug.html

This coupled with a 400W solar array should manage to look after my 260Ah AGM battery throughout grey winters across Europe.

Can anyone confirm I've made the right choice? On paper it's all good, but I'd like to be 100% sure this model is adapted to AGM batteries due to the reasons below:

1) I'm aware that some manufacturers don't configure the End Amps setting correctly for AGM charging, leaving it at 2% (flooded batteries) instead of 4% (due to AGMs having lower internal resistance), therefore overcharging/damaging the battery. This Victron charger has a "high voltage mode" rather than an "AGM mode". There is mention of AGM charging in the manual, but it's almost described like a "once size fits all" charger, which has me somewhat worried now that I've ordered the damn thing.

2) The Victron user manual recommends that I charge my battery at 14.4V. Until reading this I was pretty sure AGMs need 14.6-14.8V to charge properly. Am I wrong?

NORMAL (14,4V): recommended for flooded flat plate lead
antimony batteries (starter batteries), flat plate gel and AGM
batteries.
HIGH (14,7V): recommended for flooded lead calcium batteries,
Optima spiral cell batteries and Odyssey batteries.

3) Another point of concern about this product: in the user manual, they recommend occasionally reconditioning AGM batteries (see passage from the user manual below). I thought AGMs should never, ever be reconditioned!?
My battery has indeed stayed below 80% for over three weeks due to the weak mains charger & insufficient solar power. Would you recommend a "reconditioning" cycle as Victron suggest?

"A lead-acid battery that has been insufficiently charged or has
been left discharged during days or weeks will deteriorate due to
sulfation¹. If caught in time, sulfation can sometimes be partially
reversed by charging the battery with low current up to a higher
voltage. Remarks:
a) Reconditioning should be applied only occasionally to flat plate VRLA
(gel and AGM) batteries because the resulting gassing will dry out the
electrolyte"

Thanks in advance!

 

[marconi]

I have been looking at the un-answered posts and see you asked a question in Oct 19. I don't have a definitive response but maybe some re-assurance on your purchase. Victron is a very good make which I have used in half-a-dozen off grid solar pv applications with Victron 100Ah or 200Ah AGM batteries. I have set-up Victron solar chargers for AGM batteries as advised by Victron in the charger literature and not tweaked the voltages or currents - preferring to let the 'wisdom of the in-built' software worry about how best to charge the battery. I put a date on the battery so I know its age and useage.

I have not set up for reconditioning - I read 'only occasionally' as a strong clue to hardly ever if at all, nor do I set up for periodic equalisation.

One thing you might want to be careful about is the maximum charge current limit as attempting to charge a battery to quickly causes heating and incremental damage reducing the life of the battery. In our applications we use the advice provided for Victron AGM Valve Regulated Lead Acid batteries which says keep the charge below 0.2 x C where C is the Ah of the battery, so 20A for 100Ah battery. If you connected the charger at the same time as the solar pv was active you may exceed this limit.

I cannot respond on the 'end Amps' query for the reasons above.

As a caution to you - if you have not done so - you should (I would say must) have a fuse or circuit breaker close to one of the battery terminals. If the battery has one terminal connected to metalwork - say the chassis of a vehicle - then the circuit breaker/fuse is put into the lead to the other terminal. And the terminals must e covered with plastic boots. Do not underestimate the arc, flash, plasma and heat produced if by accident you short circuit these types of battery. One can buy arc flash protection equipment (Class 2).

I use these:

Fuses, Fuse Holders/Boxes & Circuit Breakers | 12 Volt Planet - https://www.12voltplanet.co.uk/fusing-circuit-protection.html

Push-On Terminal Insulators | 12 Volt Planet - https://www.12voltplanet.co.uk/push-on-terminal-covers-insulators.html

Arc Flash Protection - https://www.boddingtons-electrical.com/personal-protective-equipment/arc-flash-protection/

What Are the 4 Different Arc Flash PPE Categories in NFPA 70E? - https://enesproppe.com/blogs/electrical-safety-stories/what-are-the-4-different-arc-flash-ppe-categories-in-nfpa-70e

 

[Zerax]

+ 1 for Marconi's comments.... I'm also a fan of Victron equipment... and use their charge controllers. They also have an excellent forum where you can ask questions and get proper answers.

I wasn't certain from the OP whether they were Victron batteries or not... if not, I'd always use the battery manufacturers recommended charging regimen rather than any 'general' settings etc.