Mark Hanson via EV wrote:
Sounds like it's best to keep a spare small battery capable of 450a or ultra
caps by Maxwell etc like Lee mentioned. It's a bummer to be in the middle of a
big lake and the boat won't start for the next skier.
When an ICE starting battery "suddenly" goes dead, it's usually because
it's been slowly failing for a long time, and finally crossed the
threshold where it no longer has the "ooomph" needed to start the
engine. Most vehicles have no instrumentation at all on the battery; so
the owner has no idea that the battery is getting weaker and weaker.
You know a lot about batteries. If you added at the very least a
voltmeter and ammeter, you should be able to tell if something is going
wrong. For instance, if the voltage sags more than normal during
starting, or if the charging current after starting does not rise to a
high level for a short time and then drop off to a normal "trickle
charge" level, then something is failing.
Best regards
Mark
Sent from my iPhone
On Aug 12, 2018, at 7:31 PM, Bobby Keeland <keela...@gmail.com> wrote:
Mark Hanson asked "curious if LiFePO4 dies suddenly or gradually like lead."
My experience with lead acid batteries in both a Dodge RAM pickup and in a
Subaru SUV is that they were working great when I stopped at the dealership
(Dodge) and pharmacy (Subaru), but when I got back in the vehicles the battery
was dead. No obvious gradual decline.
On Sat, Aug 11, 2018, 10:04 AM mark hanson via EV <ev@lists.evdl.org> wrote:
Thanks Cor,
Yes, it has a standard 14V alternator regulated. I start and stop frequently
as skiers are getting in/out of the boat, so curious if LiFePO4 dies suddenly
or gradually like lead. I assume a small battery like this would start fine
one second and then not, so I keep a spare battery in the boat (unless someone
has any real data on this battery, couldn’t find on the great god google) .
What is the projective life, 1,5,10 years?
I had an electric boat www.evalbnum.com/2749
but couldn’t H20 ski behind it so bought a lean burn Honda BFP60, same engine
that was in my 2000 (real) Insight 65mpg. In the alum 1200lb 6x16 boat, gets
6.5MPG which is considered “good” most fiberglass 3400lbs are 2.3MPG.
Have a renewable energy day,
Mark
Mark E. Hanson
184 Vista Lane
Fincastle, VA 24090
540-473-1248 phone & FAX, 540-816-0812 cell
REEVA: community service RE & EV project club
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From: Cor van de Water [mailto:cor.vandewa...@gmail.com]
Sent: Saturday, August 11, 2018 12:19 AM
To: Electric Vehicle Discussion List
Cc: mark hanson
Subject: Re: [EVDL] Shorai LiFePO4 LFX36L3-BS12 Longevity Reviews
Mark,
I presume that your boat engine has an alternator and is generating 14v as long
as it keeps running, so not too likely that your boat suddenly dies in the
middle of the lake, but good to have backup.
That said, your 4lbs battery probably has between 200 to 300 Wh of capacity at
best, using normal density numbers.
At 12.8v this means probably 15 to 20 Ah so the usual Chinese twice (or more)
overspec.
Cor.
On Fri, Aug 10, 2018, 8:29 PM mark hanson via EV <ev@lists.evdl.org> wrote:
Hi Folks,
I was curious if anyone has used/evaluated the Shorai LiFePO4, Lithium Iron
Phosphate LXF35L3-BS12 I bought from Amazon $250 with charger/balancer $67
for my HondaBFP60 boat (1000cc similar to large motorcycle) claims 550
cranking amps, 36ah but only weighs 4 lbs so probably Chinese inflated
specs. Looks more like 7-14ah MC battery. It does start the engine with
little voltage sag, 11V whereas the lead battery sags to 8V when starting.
I'm concerned that it may suddenly die out in the middle of the 80 mile lake
here Smith Mountain Lake near Roanoke, VA so keep a spare tractor battery on
the boat just incase. I replaced a 40lb lead marine battery to save some
weight but curious about the longevity and how LiFePO4 dies, if it's sudden
or gives some warning like lead (that gets gradually saggy when starting).
Have a renewable energy day,
Mark
--
"Verschlimmbessern" (German, verb) - To make something worse by
trying to improve it. (English translation: "Microsoft"?)
--
Lee Hart, 814 8th Ave N, Sartell MN 56377, www.sunrise-ev.com
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