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Jetta03's avatar
Jetta03
Explorer
Apr 26, 2015

Trojan T-105 charging specs

Hi all. Thx for the help with my previous question re: 6v battery selection

So I went ahead and bought the Trojan T-105's mostly because of reputation, the shop (Rocky's in Edmonton, awesome btw) matched the price, and they were a bit shorter than the Crown's and fit my battery box better.

Question is around charging. In looking at the specsheet for the T-105's I saw they specify a 14.8 volt absorption charge. Is there really any noticeable difference to be seen in capacity or lifespan by going to the extra trouble of increasing to 14.8? I believe most chargers are probably 14 or so volts at this stage. Thoughts?

Thx

25 Replies

  • The hydrometer is the BS detector in all of the assumptions listed above. If the cycled battery regains full specific gravity in all cells in a timely manner, that charging protocol is correct for that battery. There is no other way to judge the efficacy of a charger. This is a black and white area with shades of gray being BS. Reread what I wrote about in A Timely Manner. This is where many amateur's assumptions collide with reality.
  • Typical three stage converter is 14.4 and 13.6 charging and will work fine.
    Plenty of RVs have reported excellent 10+ year life with Trojan without perfectly matching the 14.8 absorption voltage.

    Do verify what voltage actually gets on your battery. Good luck if you have a WFCO.

    Properly working multistage converters do not kill these batteries... poor maintenance by the owner is what kills them.
  • At 14.4 volts, the battery probably will not get as warm, and probably will last longer. At 14.8 volts, that is probably the maximum voltage that they should be charged at.

    When I would charge my batteries, if I was really low, I would set the charger to only 50% and keep the amperage to around 35 amps, so that they did not warm the battery, or boil off to much water.

    Normally I would use the solar system to charge the battery, and it would take all day, slowly charging at 21 amps, tapering off near nightfall. This provided me with 13 years of battery life from the factory 4 Trojan batteries.

    Good luck!

    Fred.
  • I would think that the most common DC batteries are desined to be charged on the most common charging equipment. The engineers of this equipment are not stupid. Any later model 2-3-4 stage converter/charger is designed to adequately charge any of the common DC batteries out there.
    All of them charge at well over 14 volts, My PD 9245 goes to 14.6, floats at 13,3-5. If you think that your Trojans need special charging, I'd say, go for it,
    If I thought Trojans or any other DC battery needed special charging, I would not buy them.I myself would not even look at,....or care what the charging specs were, as they would do fine w/ my PD charger.
  • You can bet your last Loonie Trojan is right on the money with their recommendation.

    Standard "Smart Chargers" kill more batteries than lights accidentally left on times 50.

    There are plenty of threads here that discuss this issue in detail.

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