Re: Firefly Battery Update.

Arno Luijten

Hi Bill,

You did an excellent job in charting the way your batteries are behaving!

I guess I'm just disappointed by the expectations the Sales Blurb set for me about the the way these batteries behave. I consider a 0.1 C load on a battery not exceptional at least not to see voltages dropping to close to 23 Volt. This is a point where all the voltage alarms start sounding on our boat if it lasts longer then 10 secs or so. With an big inverter, a freezer and two fridges getting to these loads is not so hard. The loads are not continuous but long enough to set off the alarms. So in my case the set of batteries I had was not big enough to withstand an excessive voltage drop. When sailing it also means a lot of generator time as the solar panels we have is not be be enough to compensate all usage in the 24h timeframe. Charging was better then with AGM but still the last 20% takes a lot of time. And this is where I got into a catch-22 situation as I wanted the batteries at high SOC because of the voltage drop.
We are now on Lithium and that makes a lot of difference. But that was to be expected. Thanks to the dimensional aspects of the replacement it also allowed us to install 700Ah@24V. But as said before, the cost of this whole exercise is something I really want to forget.

I'm happy these batteries work good for you as I don't believe they are bad batteries but their use-case is different then I expected.

Arno Luijten
SV Luna,

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