Trojan T105RE

[Motrukdriver]

Is there enough of a benefit to use the T105RE over the standard T105 battery.  Both have 225 Ahr but there is a 5 pound difference and about a $30 increase in cost per battery to go with the RE.  I've been reading about them and several sites are saying that the standard T105 isn't really designed for solar applications where the RE series is.  They are all saying using the standard T105 in this scenario shortens the lifespan.  So with a 6 battery system you are adding an additional 30 pounds and $180 more or less in price.  Yes?  No?  I'm in study mode now and trying to learn all I can before the purchasing begins.

[sternwake]

The RE's are also taller IIRC.

regarding solar applications, many manufacturers just slap a green RE label on their regular offerings.

Concorde, who make the venerable Lifeline AGM battery, market a battery for solar called sunextender or something like that.

A solar battery should be happy with low and slow recharges, but in the user manual they still say to apply no less than 20 amps per 100Ah of capacity to the battery when it is to be regularly depleted to the 505 state of charge level, which is highly unrealistic on Solar.

The RE is likely a better battery, but whether those extra 5 lbs of lead are magically able to make the batteries resistant to repeated partial state of charge cycling, is of course debatable and with no data those debates would be a useless waste of time.

if one reads the recommneded charging specs of regular trojan batteries they want to be brought to absorption voltage(14.82v) with 10 to 13 amps per 100Ah of battery capacity.

No solar installation is going to have that kind of amperage available unless it is only flipped on at 10:30 am and is well more than a 2:1 ratio of wattage to AH.

Everything is a compromise and meeting exact recommended charge parameters is a lesson in frustrated futility.

Just about any lead acid battery, besides starting batteries, is going to give good cycle life as long as it is fully recharged often and promptly, even if it is depleted below 50%.

Full charge requires time at absorption voltage, and it takes time and amperage to reach absorption voltage. The more amps available the less time to reach absorption voltage.

how much time is determined by how many amps are available and a hydrometer. With AGMs one requires an Ammeter and battteries at absorption voltage to determine full charge, or an AH counter and a few grains of salt..

Get to full charge every day and the batteries will be happy
getting to 98% every day will yield only half the total cycles before replacement is required.

The extra money spent on perceived better quality batteries might be better spent on more solar to ensure that absorption voltage is hit earlier in the day, so that it can be held long enough for 98% to become 100%

That extra money for RE's could be better spent on a controller that allows one to change absorption voltage and duration.
The extra money for the RE's might be better spent on thicker copper charging circuits or a better plug in charging source which can perform an EQ charge at 16 volts when required.

Trojan makes a great battery, but beware of marketing.
Marketer's promise that physics can be defied.
Physics prove that marketers are paid by greedy liars and guilty of the same