Keeping a 12v battery charged above 80%

[amdx]

On 6/13/2012 2:06 PM, Wrecker wrote:

On 06/13/2012 10:42 AM, amdx wrote:
On 6/9/2012 10:57 PM, Wrecker wrote:

I bought a Battery Tender Jr. for my motorcycle.
...
After a year, I smashed it with a sledgehammer and
threw it in the trash.

I note Amazon.com has 761 customer reviews.
95% are 4 or 5 star and 84% are 5 star.
Leaving only *5% unhappy with the product,
looks like you got a bad one.

Yep. And when I needed the warranty (5 years I think it was, not
lifetime), I found it was laughable.

* I think it might be lower, as unhappy people
are more likely to complain.

People also like to push their choices, and rally others to follow.
Everyone likes to be an authority. I see that so often on hokey
Newegg.com reviews.

Mikek

hmm.. maybe!
I bought an FM transmitter from Amazon 6 months ago and wrote a positive
review after setting it up and seeing how great it worked. Just this
morning I was thinking how well it works and I should write another
review and tell everyone!
http://www.amazon.com/0-5-Fail-Safe-Long-Range-Transmitter/dp/B003FO4UHW/ref=sr_1_12?s=automotive&ie=UTF8&qid=1339624789&sr=1-12&keywords=fm+transmitter++++
Dang, now I'm not happy the price has dropped 50%!
Ok, I'm still happy, I might but another one.
Mikek

 

[krw@att.bizzzzzzzzzzzz]

On Wed, 13 Jun 2012 17:12:56 -0500, amdx <amdx@knology.net> wrote:

On 6/13/2012 2:06 PM, Wrecker wrote:
On 06/13/2012 10:42 AM, amdx wrote:
On 6/9/2012 10:57 PM, Wrecker wrote:

I bought a Battery Tender Jr. for my motorcycle.
...
After a year, I smashed it with a sledgehammer and
threw it in the trash.

I note Amazon.com has 761 customer reviews.
95% are 4 or 5 star and 84% are 5 star.
Leaving only *5% unhappy with the product,
looks like you got a bad one.

Yep. And when I needed the warranty (5 years I think it was, not
lifetime), I found it was laughable.

* I think it might be lower, as unhappy people
are more likely to complain.

People also like to push their choices, and rally others to follow.
Everyone likes to be an authority. I see that so often on hokey
Newegg.com reviews.

Mikek



hmm.. maybe!
I bought an FM transmitter from Amazon 6 months ago and wrote a positive
review after setting it up and seeing how great it worked. Just this
morning I was thinking how well it works and I should write another
review and tell everyone!
http://www.amazon.com/0-5-Fail-Safe-Long-Range-Transmitter/dp/B003FO4UHW/ref=sr_1_12?s=automotive&ie=UTF8&qid=1339624789&sr=1-12&keywords=fm+transmitter++++
Dang, now I'm not happy the price has dropped 50%!
Ok, I'm still happy, I might but another one.
Mikek

Wrecker makes a good point. I see tons of reviews where the buyer just
unwrapped the present and talks about how well it works. OTOH, I generally
look at the negative reviews. I want to see what problems were encountered
and how they were fixed. If the seller takes care of the problem, that's a
positive in my book.

 

[Grant]

On Wed, 13 Jun 2012 18:13:17 +0200, tuinkabouter <dachthetniet@net.invalid> wrote:

On 6/12/2012 11:43 PM, Bob Engelhardt wrote:
news@jecarter.us wrote:
...
Ideally, a lead acid battery is never discharged below 50% - ...

How is charge measured? Voltage? Does 50% mean a 12v battery at 6v? That
doesn't sound right.

Read the wiki: https://en.wikipedia.org/wiki/Lead%E2%80%93acid_battery
Look at the open voltage caracteristic (the name is misleding):

https://en.wikipedia.org/wiki/File:Lead-acid_voltage_vs_SOC.PNG

When a lead battery starts gassing it is full.

No, when a LA battery starts gassing it is about 80% charged, putting
in that last 20% take three hours at C/10, after up to five hours at
C/5 to get to the gassing point.

Old numbers for flooded traction batteries. Sealed LA batteries may
have a different charge curve.

Grant.