Lifeline GPL-27T AGM Battery Upgrade

Thanks for the info Beagle..

woodhog wrote:
Where the AGM batteries seem to require these strict charging criteria, do our truck alternators when charging the AGM's meet these requirements when the batteries are being charged with the truck running?

Generally, No.

Would the trucks alternator voltage eventually damage or diminish the life of high quality AGM batteries?

Possibly, Yes.

If the alternator set point is too low, it will undercharge your camper batteries, particularly if there is additional voltage drop in the too-small wiring to the camper. Undercharging will not by itself damage the batteries, if there is another source of proper charging voltage such as a line or solar charger.

If the alternator set point is too high, you will dry out the absorbed electrolyte in the AGM which cannot be replaced. I have never seen too high voltages in any truck I have owned. Often the set point is above the 13.4V usually recommended for AGM float operation, but very rarely does anyone drive more than 8 or 10 hours at a time and that won't hurt them. If you plan on driving for several days straight with no shut downs, you might consider unplugging the cord for some periods.

So practically, it is unlikely to be a problem for most people. I have a charge controller between the truck and camper than regulates charge voltage to the AGMs, but this is probably overkill.

Where the AGM batteries seem to require these strict charging criteria, do our truck alternators when charging the AGM's meet these requirements when the batteries are being charged with the truck running?
Would the trucks alternator voltage eventually damage or diminish the life of high quality AGM batteries?

I am pretty familiar with Lifeline batteries and their charge recommendations. They do say a charge rate of 0.2C is desirable (and most campers would have that in their line charger), but also say that an alternative is a slower rate for a longer period. As for as I am aware, Lifeline alone among AGM manufacturers allows a low equalization charge, but they do not recommend it routinely (as flooded cell manufacturers do), rather only when the battery is already showing signs of sulfation.

I have had numerous Lifeline battery banks up to 900 AH, the capability to charge them at over 1.5C, and full instrumentation. My experience, and that of most independent tests is: charge them to the right voltages (temp comp is desirable), charge them fully periodically even though that takes 8 or more hours, and they will last a long time.

All that said, when I replace the 10 year old Lifeline bank on the boat, I think I will try Firefly foamed carbon, specifically because of their unique ability to withstand partial state of charge for long periods without any performance degradation, independently tested and confirmed.

Great batteries. I find they do take a long Absorb time, so I have trouble keeping them fully charged boondocking. Shore can take 18-24hrs to really do the job.

HMS Beagle wrote:
I think maybe the finicky nature of AGMs is being overstated. They will benefit - a little - from a heavy charge occasionally.

The manufacturer flatly states more initial charge current is better.

Without the ocasional high amp recharge, the time it takes for amps to taper to 0.5% of capacity takes much longer, especially, and more so when accumulating many deep cycles back to back.

While I have a thin plate pure lead Northstar AGM, not a lifeline, I can easily notice when too many low and slow solar only recharges has tanked performance,( voltage drops much lower for AH removed under a given load) and a high amp recharge to a true 100%, is the resetting cure. I deep cycle nearly daily and have a battery monitor at my right hand and this behavior is overwhelmingly obvious. The high amp recharge is Key.

100% recharges are of course important even at a slower rate to achieve them, but when the cycles are deep on these high$$ AGM's, so is the initial charge current as it needs to get that electrolyte a migrating through the glass matting.

Disregard the necessity of an occasional high amp recharge at the cost of the longevity of your expensive AGM battery.
Read the lifeline manual regarding charging parameters, more than once.


And lifeline allows and recommends EQ charges, they just call them 'conditioning' charges since 'Equalization' freaks out the masses when typed near the letters 'AGM'.

Scroll to page 19, read and reread:

http://lifelineb.wpengine.com/wp-content/uploads/2015/12/manual.pdf

You have a 650$ battery bank, do not disregard the manufacturer recommendations as to proper recharging.

Low and slow solar only recharges, on back to back deep cycles, even to 100%, will have these batteries fail prematurely.

The less deep the cycle, the less important the high amp recharge becomes. So claims of longevity without this data point are not much value.

landyacht318 wrote:
These lifelines, if cycled to 50% regularly, need a high amp recharge regularly too. Lifeline recommends 20 amp per 100Ah of capacity minimum when deeply cycled and no upper limits on charging amps. They flat out say more is better.

90 watts feeding 200AH of lifeline AGM, or Any AGM, is woefully inadequate if these batteries are ever discharged below 90%.

Expensive batteries to kill prematurely.

People tend to paint AGMs with a Super battery brush due to their price, but really they are finicky princesses waiting for an excuse to pack up all their shoes, belittle you, then leave, when their particular demands are not met.

if you cycle them deeply, feed them properly, be able to feed them at least 40 amps from their most depleted state until they reach 14.4v and hold 14.4v until amps required to hold them at 14.4 @77f tapers to just 1 amp.

If you can't do this, you will have very effective paperweights, very prematurely, for top dollar.


I have Northstar AGM group 27 at 90Ah capacity.

I removed 18Ah to take it to 80% State of charge.

How long do you think it took to recharge fully with a 40 amp capable charger?

3.5 hours at 14.5 volts before amps tapered to 0.45.

If this battery was not recently high amp recharged, it could take twice as long for amps to taper to 0.45 @ 14.5.

Lifeline is top quality, but it is not going to make up for improper recharging, and 90 watts for 200Ah is woefully inadequate.

The PD9245 would be a good converter for lifeline setpoints, but the PD9270 would be better.

Do not discount the need for an AGM to get a high amp recharge occasionally, at a minimum. 100% recharges achieved often are paramount, but so is the high amp recharge.

Do note lesser$$ AGMS have a 30 amp per 100Ah capacity maximum current, but even these AGMs will benefit from charge rates approaching 30% when cycled deeply, often.

If you can't properly charge a battery according to its needs, then get the cheapest flooded marine battery you can find, as it will hurt less when it fails prematurely.

Lifeline's huge $$ does not make it immune to improper charging. It actually is more demanding of proper and particular recharging parameters to achieve any where near its potential cycle lifespan.

X2

Wardster wrote:
With respect to the comment about converters, my NL has a PD4045KA (30A) in it. Is that sufficient?

I assume the 30A is the load center input(120vac). I think the 4045 will put 45 amps into the battery. This is on the low side of adequate for fast charging with a generator. Plugged in is fine.

I think maybe the finicky nature of AGMs is being overstated. They will benefit - a little - from a heavy charge occasionally. It will take them longer to reach 100 percent state of charge at 14.1 that 14.4, but they will get there. I agree with the advice to use the flooded setting (vs. gel) if those are your only choices. Mainly because the float setting for gel will be too high for AGM (13.8 vs. 13.4). A temperature compensating controller is a very good idea as well. You do need to fully charge them periodically, and never store them partially charged.

Lifeline AGMs are a high quality AGM, but the chemistry is nearly identical to other AGM batteries. The other different choices in AGM are foamed carbon (Firefly) or thin plate (Odyssey). Only foamed carbon lead acids tolerate begin operated in a partial state of charge for long periods, even flooded batteries suffer from this. But flooded batteries can be equalized to reverse the sulfation (to a large extent) while AGMs are ruined by that procedure.

Those are excellent batteries. I have two identical to yours. They will have been in service 9 years this summer. Still going strong.