Member Kimbal asked:
I’m looking at an ad on Yachtworld for a boat that has “New Victron Super Cycle AGM batteries – 3 x 125ah (2022) – Note: These batteries are a new type of AGM which approach lithium in some respects, and matches the Carbon Foam Firefly batteries performance – capable of up to 100% depth of discharge occasionally, and 60-80% frequently without damage.” Have you heard of this, and does it sound legit?
Yes, in fact that’s what we have installed on our new-to-us J/109, and testing at Ocean Planet seems to indicate that they do very well on deep discharges.
So far we have not used them enough to say anything really useful, although they are looking good after one season.
That said, it’s important to understand that Victron have two offerings with different strengths:
- Super Cycle, which we selected because we have a very small bank and occasionally will need to take it a long way down, say when aboard for a weekend, but will be able to bring up to fully charged at our wharf when we get home.
- Carbon Foam, which might be better for a long-distance cruising boat since they are more resistant to being left in a partial state of charge.
Do note though that all discharge cycles of all batteries (lithium included) reduce life to some extent (batteries are expendables) so claims like “and 60-80% frequently without damage” are simply not true. Like with Firefly, it’s important to read the fine print.