Re: Problem with new batteries keeping the charge
In comparison with your experience, this past July 23rd I installed 4 T-105 batteries as replacements for our then 7 year old batteries. Trojan indicates the battery self-discharge rate of their batteries at about 4% per month and, with all the electrical services shut off, that is about what we have observed.
Also, while some have suggested that flooded cell batteries need to be "exercised" a few times to achieve full capacity, when questioned about this, the Trojan tech's indicated that it was really not necessary, at least with their batteries.
Given the foregoing, you may have a drain you are not aware of. Several years ago we had a situation where a grounding foil has chafed through one of the positive cables in a spot under and behind our engine and only discovered by accident. Once the cable was replaced (and armored) our mysterious discharge problem was solved.
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