an invalid topic 2 AGM batteries and converter

time2roll wrote:
I think Trojan AGM said 14.7 if that matters. Will 14.8 kill that spec? Remember PD tends to sag a bit on voltage and only holds 4 hours without manual intervention.

ISTR it is four if you use the CW or max of four (could be less) if it does it by itself.

I think Trojan AGM said 14.7 if that matters. Will 14.8 kill that spec? Remember PD tends to sag a bit on voltage and only holds 4 hours without manual intervention.

To me it's all about longevity fractions of a cent spent per kWh of lifespan, and economy of recharging. This means I am a cheapskate.

I do not trust battery manufacturers.

I know with the Lifeline I can saturate charge at 14.4 volts and battery internal temps rise very modestly.

Folks have told me their Full River, Odyssey and other brand batteries do not heat up using saturation charging.

But Trojan's claim of 14.8 seems to be a tad high. I would tend to want to see proof that the battery does not gain excessive heat.

A telecomm battery is higher in impedance than other common AGM batteries. And inherent impedance IS the single throttling factor when the correct voltage is selected for recharging. It would be interesting to saturate charge a few while monitoring heat at one of the lead terminals. If temps climb beyond say 7F Delta T, within 20 minutes, reduce the voltage.

14.4 volts is a good all-around base number.

AND AND AND AND

I need to keep reminding of this caveat.

If solar can be used to make up the last 10% of amp hour recharge DO IT! IT reduces generator run time and is the friendliest way to get to the magic .5% of amp hours fully charged status.

The quantity of amperage needed to do this must exceed the number of amp hours to full charge AFTER deducting for hotel loads. If you are looking for a makeup of a twenty amp hour shortage, then your solar regulator MUST be set for a 14.4 volt limit AND exceed the charge acceptance level if it turns out to be a race until sunset.

This is all linear. Typical chemistry straightjacket level deducement.

a) the closer you get to 100% recharge the less deterioration of capacity. A 95% level of recharge may allow a month or so of no degradation with a 70% level of recharge will deteriorate the battery.

b) the less depth of discharge the less deterioration of capacity.

c) like a maestro in charge of the symphony. You have the baton.

d) No one forces you to use added battery capacity (more batteries)

e) A comfortable camping experience with a 40% depth of discharge is ideal. It really improves the lifespan of the battery

f) Remember, when one battery is accepting say 20 amperes are 85% state of recharge a second battery means 40 amps, a third 60 amps. Which one do you think your generator likes the best? Your wallet?

I have used a pair of ex-golf car 12v T-1275s from 2013 until this year, and was very pleased with them. I posted a few times :) on how that went.

Latest thing is an AGM 12v "6GFM250" in an 8D format (big and heavy) as an alternative to a pair of 6s or 12s. (See other thread on that="opinion please") Might be good--too soon to tell.

I hope this helps.

OK, not a total battery geek,,,,, yet, but have watched and listened enough to get that a multi use battery ie; deep cycle/starting marine battery is not going to do as well as a Golf Cart battery, have seen very little for some reason about 12 volt deep cycle batteries such as sweeper batteries which can be 12 volt 200+ amphr, in a single unit for under $250, vs the GC-2's
Do they both poorly handle 50% + discharge rates?
Is one any better than the other?
Do the GC batteries better handle bouncing around?
Can AGM's better handle a 75% discharge?
And how long to recharge both types?
Those of you deeply invested in the differing types seem to get so deep into the littlest differences, that stating the basics in these threads gets by-passed.
Would love to see a site or thread explain the advantages of each.

I gather from Mex's posts, that "saturation charging" means you hit the battery with such high amps wrt its size in AH at the charger's set voltage, at whatever SOC the battery it is at, that it goes straight to Absorption--amps tapering--and you get no constant amps Bulk stage with your current-limited charger.

Of course this means the lower the SOC of the battery at any charger set voltage, the higher the charger's amps limit has to be. And that means you need enough generator VA to run that charger to do that.

red31 wrote:

MEXICOWANDERER wrote:

Charging a STANDARD AGM BATTERY by generator at any potential not near saturation charging makes about as much sense as ...

What does saturation charging mean for the guy that is listening.?

Give it all ya got?
Get er done?
Get the battery to absorption pt voltage (14.?) ASAP with however much energy it takes and let it taper from there and then cut the generator off?

Yep say 14.4 is the absorption, as many Amps as needed to reach it instantly.

MEXICOWANDERER wrote:

Charging a STANDARD AGM BATTERY by generator at any potential not near saturation charging makes about as much sense as ...

What does saturation charging mean for the guy that is listening.?

Give it all ya got?
Get er done?
Get the battery to absorption pt voltage (14.?) ASAP with however much energy it takes and let it taper from there and then cut the generator off?