Re: (ET) Elec-trak Digest, Vol 14, Issue 37

["David Roden" <etpost drmm net>]

On 29 Mar 2016 at 12:18, Robert wrote:

> A 100A battery should be charged with C/10 to C/20, that means 100/10 =
> 10 amps max charge current. 

I assume that by "100A battery" you mean 100 AH.

Most batteries will benefit from an initial charge of at least C/10.  C/20 
will be OK for some.  I wouldn't recommend going much lower than that.  A 
5 
amp charger or less would be undersized for an ET.

It's fine for the current to taper after a while.  However, batteries 
really 
like that opening grand slam for some reason.  I'm not an electrochemist 
and 
I have no clue why.

This is the reason that Lester golf car chargers charge at an initial rate 
of 20-22 amps (220AH batteries).

Some batteries will actually lose capacity if they aren't charged with a 
high enough initial current.  In the mid-1990s, Hawker Genesis AGM 
batteries 
got quite a reputation for failing early when not charged with enough 
current.

> It's also better to charge each battery individually or in pairs of
> two 

For valve regulated batteries, it would be even better if you could charge 
each CELL individually.  For most batteries, regulating the charge at the 
monoblock level is about all you can hope for.

I guess block or even cell balancing would be nice for flooded batteries 
too, but I've never done it, and I don't know anyone who has.  They're 
much 
more tolerant of equalization by overcharging than VRR batteries are.  
Also, 
in most applications, the operation economy gained probably doesn't offset 
the cost of the hardware to do the balancing.

Batteries are fascinating critters.  :-)


David Roden - Akron, Ohio, USA

= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = 
Note: mail sent to the "etpost" address will not reach me.  To send 
me a private message, please use the address shown at the bottom
of this page : http://www.evdl.org/help/
= = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = =