What specific battery did you use for the replacement set?
 
I  have just purchased this sparrow that has originial batteries and have just
got it to its new home.
 
I wnat to use if of an 8 mile commute, at about 45 mph one way and need to look
at doing the whole thing.
 
Is there a procedure I need to follow to get down to the batteries and to follw
to make sure I don't mess things up?

--- On Fri, 7/3/09, w_satterfield <wade@...> wrote:


From: w_satterfield <wade@...>
Subject: [sparrow_ev] Re: Batteries
To: sparrow_ev@yahoogroups.com
Date: Friday, July 3, 2009, 3:18 PM








> If some batteries are old an can hold a charge but the others are dead is it
best to replace them all to keep the system running right?

I only replace batteries one or two at a time and have never replaced the whole
pack.

I have been driving my sparrow nearly every day for 7 years. As soon as I cannot
make the 13 mile trip to work and back, then I find the weakest battery in the
pack and replace that one.

You can see more detail at http://thetruthmain ly.com/sparrow/ batteries. html.
The web site is a little out of date. I have replaced two more batteries since I
last updated the page. I have replaced 33 batteries and gone almost 18K miles.

If you are trying to resurrect a long idle sparrow, then as Jake suggested,
replacing the whole pack might be the best thing. Finding the few good batteries
in the pack can be really hard. If the pack is in regular use, then the
batteries generally fail one at a time, and it is not too hard to find one bad
battery. You can find the bad battery with a nice meter, but I agree with Eino
that a BMS makes this much easier. I was able to make a simple BMS for about
$50.

I would agree with replacing the whole pack, if after replacing one battery, the
other 12 were soon to fail. Some batteries last 11k miles, while others only
last 2k miles. This variance leads me to believe that replacing the whole pack
will cause me to throw away batteries that are not even half used up.

Jake may well be right that mixing a new battery into an old pack will keep that
new battery from lasting as long as it would in a new pack. On the other hand,
it is a certainty that replacing the whole pack when one battery is bad will
keep the other 12 batteries in the old pack from lasting as long as they would
if I only replace one battery. By replacing batteries one at a time, I am
avoiding a certain waste but risking a possible waste.

If I were paying someone to replace batteries for me, then replacing the whole
pack might make more sense. It takes me an hour to replace a battery under the
hood, and about a half an hour to replace one under the seat. One at a time the
whole pack could take ~10 hours to replace, but as a group they might take only
3 hours to replace. If I were paying someone $50 per hour, saving 7 hours of
labor costs might be worth giving up the chance to milk all I can out of the
batteries.

Wade
















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