I guess Deka 9A31s aren't as good as they seem...

[TimK]

Hi All,

I've been swamped lately and waiting for parts, so there are few
updates on the blog. One thing I would like to report to everyone is
that I visted Synkromotive two days ago and they told me about their
history with the Deka 9A31 series of batteries.
It turns out that all the public buses for Oregon and Washington
have four Deka group 31 batteries in them. The bus companies were
very frustrated because the batteries kept dying after 10-12 months of
operation. Synkromotive worked with these companies and found out
that the Deka warranty was only 12 months and that they only list 150
full cycles of lifetime operation. All the buses now use Odyssey
group 31 batteries and have not had any issues.
It looks like the amp-hour and amperage rating for the Dekas isn't
too bad, but the lifetime is horrible. The Odyssey batteries are
twice as much but last three times as long and have even better
amperage ratings. John Wayland uses Odyssey batteries in his EVs.
Northwest Battery here in portland highly recommended Discover EV31a-
a and FullRiver group 31 batteries over the Dekas as well, but they
also cost more. The ZAP cars have a Discover EV31a-a upgrade, so they
use them too.
I'm just passing this along in case anyone was considering group 31
batteries.

Cheers,
Tim

[DavidH]

I have a Deka starting battery in my 2004 Civic and it is a POS. It is
actually the thrid Deka in a year, and is going bad after 4 months. It
will discharge if left in the car for 4 days of not being used. I
thought it may have been my security system, but after I placed it
onto my smart charger it said that there was an internal short and it
was sulfated. This is the thrid Deka in a row that has died on me, and
the car is used almost everyday.