SLA Charge and Equalize

Maine Sail · Mar 22, 2017

LeslieTroyer said:
I wouldn't choose a Sealed Lead Acid (SLA) battery by choice - but that is what came with the boat - so I'm wondering if I can Equalize them, especially as I can't replace boiled off water or measure the SG of the cells.

The (4) batteries are some kind of 6V golf cart (GC2) the labels are positioned so it is impossible to read without pulling the batteries.

I also recently added a Balmer 614 and am using the Standard Lead Acid rather than Deep Charge Lead Acid to limit water evaporation. (Alternator & Battery Temp sensors are installed, belt tamer on 70% for 105A LN 8MR alternator, 3/8 single belt, Universal M25)

I also purchased a Sterling 40A charger from you - and was planning on using the "Sealed Lead acid" profile -

Any hints on prolonging the life of these things?

Thanks for the support!

Can you get me a photo of the batteries? Brand? Model?

jssailem · Mar 23, 2017

It is great when they fail to identify the date of the battery production. They must be new Les.

jssailem · Mar 23, 2017

Located the business. They identify as a manufacturer in Anchorage.
https://ssl.batteryspecialistsalaska.com/contact.aspx
Also have a Facebook page.
https://www.facebook.com/Battery-Specialists-of-Alaska-1018045718229350/

Maine Sail · Mar 23, 2017

LeslieTroyer said:
I was wrong. They are AGM - only thing that looked like a model is BAGC2. No amp-hrs listed

Thanks
Les
View attachment 134536 View attachment 134537

LeslieTroyer said:
I was wrong. They are AGM - only thing that looked like a model is BAGC2. No amp-hrs listed

Without seeing a zoomed-out version of the battery its a bit tough to say for sure, but I am 99% sure those are a re-labeld East Penn / Deka 8AGC2.

These days I believe Whatcom is re-labeling the new Crown AGM's as "Alaskan Gold" but the Crown's are all black cases and Deka is gray with a black top. Also East Penn used to reference a 68F baseline for charge voltage temp compensation on their AGM and GEL series batteries, where everyone else uses 77F - 80F. Today they use 77F like everyone else.

LeslieTroyer said:
Charge limited to 7.3 or 14.6V. I will switch the balmer to AGM

I would not do that or you'll wind up under charging them in PSOC cyclic use. Like I mentioned in the article Installing a Battery Charger we really need to ignore the words "AGM, GEL or FLOODED" and focus on the voltages behind the words. The Balmar AGM setting is not optimal for East Penn AGM's. The closest factory programs in the Balmar would be FDC or OPS but again, neither are "optimal". For PSOC cycling (partial state of charge) you want the highest possible safe absorption voltage you can use.

The East Penn AGM's really need all the voltage they can get as they don't tolerate PSOC cycling as well as some others. See the May 2015 and August 2015 issues of Practical Sailor for more on this.

You'll want to configure the Balmar regulator using the advanced programming feature. Reduce bulk time/b1c to 6 min and set bulk voltage/bv at 14.7V. Now set absorption voltage/Av at 14.6V for a minimum absorption time/A1c of at least 1 hour. If you are off grid a lot then your A1c duration should be longer, upwards of 3-4 hours. Regulator float should be 13.6V and ideally, unless the batteries were already fully charged it should not drop to float unless you're doing a very long motor..

Undercharging East Penn AGM's in PSOC cycling applications is really bad for them. When you are tied to a dock set your new shore charger for 14.6V and 13.5V using the custom setting.

LeslieTroyer said:
Can you equalize AGM batteries??

No, you can not condition/equalize East Penn AGM's with a charger that has an "equalize button". Only Lifeline AGM's can be equalized using a charger with an equalize button but it must be temp compensated and 15.5V limited.. The best you can do to condition them is to hold 14.6V to 14.7V for 8-10 hours to reduce sulfation.