RE: (ET) Trouble with batteries, speed control, and mower???

["Elie, Larry (L.D.)" <lelie ford com>]

Batteries???

-----Original Message-----
From: G McPherson [mailto:lifesmith hotmail com]
Sent: Tuesday, July 25, 2000 8:35 AM
To: elec-trak cosmos5 phy tufts edu
Subject: (ET) Trouble with battreis, speed control, and mower???

<snips>

;1. The power pack appeared to be fully charged but when I checked the 
cells

;their specific gravity would range from 1125- 1175.   The spread 
concerned 
;me a little but the low level concerned me more.  No plates were exposed
but 
;the electrolite was generally low.  I charged it for a few hours with no 
;appreciable change in the "fuel level" meter.   When I started to use the 
;tractor I noticed that it seemed listless and under powered the fuel 
level 
;meter immediately "full" to "low " and it seems to struggle under load.  
So

;I stopped and checked for undue friction. However  the wheels were free 
and

;the brake was not dragging so put it on charge again and toped up the 
cells

;with distilled water.  After a "6 to 10 " year" charge (7 hours) it only 
;showed 85% full.  I do not want to over charge the pack.  But something 
;seems amis.  Are my batteries toast or just out of shape?  Do I continue 
to

;charge them or  am I facing replacing them?

Try a trickle charger on either pairs (if it is 12V) or singles (for 6V) 
for

HOURS until the reading with a DVM is within .2V each battery.  Within 1V 
or

even 1/2V is NOT that close in charge (a battery to first approximation is 
a

non-linear integrator, but that's another story).  Check the specific
gravity 
to see if they are equal.  I suspect they are not fully charged.

;2. The Speed Control lever would shift from forward to reverse normally 
but

;would not accelerate to a higher speed at all just "on or off"  All the 
;graduated speed control had disappeared.  Could this be related to the 
low 
;battery level or are there switch contacts that need to be cleaned?

No, it sounds like contacts or relays/contactors.  Low batteries may let 
you

back-up and not go forward, but I haven't seen this.

;3. When I inspected the mover I discovered that one of the blades was a 
;little stiff and when I tried it under power the motor would heat up.  Is 
;this a lubrication issue (if so where do I lubricate?) or could  the 
shaft 
;or bearing be worn or damaged?  What are the possibilities and how should 
I

;approach it.?
 
Bearing replacement time.  A little stiffness is ok as long as the 
batteries

hold enough charge to let you mow your whole lawn; it is after all, taking 
more current than it should.  If it doesn't turn fast enough, or, if the 
power use is too high, the bearings need to be replaced.  I only use true 
sealed (not just shielded) bearings.

Larry Elie