Battery Problem?

[Botman]

Sorry to ask again but have you checked if your charger is going to a fast charge indicated by a red light on the charger instead of a green light?  I had the same problem. I could charge for 48 hours and only get to the mid 2800 reading. My charging plates would read 29.3 as well. Replaced the charger and problem solved.

[Radjack]

Ya there is a solid green light on the battery charger...

[Botman]

Check this out.  Have the mower go out and when it returns to the base station because it is low on battery, immediately check your charger light.  It should be red and not green.  The red light indicates fast charging mode and it gets the charge up faster and will switch to green after a couple of hours. 

[Radjack]

I will check that...
If this is the case how do fix it? Replace charger?
How would have this changed from last year to this year?

[Botman]

Unfortunately the charger can malfunction and go bad.  Replacement is what worked for me.  Keep us posted...  As suggested by gyro, take the filter out to make sure it isnt malfunctioning.  It can go bad with time as well.

[Radjack]

Filter is out as of this morning, and last night about 20min after the bot went in to start charging the light on charger was still solid green, i will try to catch it again this afternoon/tonight to see if i ever see any red. We will see...
Third new battery from kyodo should arrive wed or thurs this week...
Will keep updating until i figure this out.
Keep the suggestions coming.

[mafster69]

When diagnosing a similar issue, I found that the problem was in the cable from the charger to the hut. I was able to verify this by using my winter charging cable. I ended up running my own wire in parallel to the charging cable which solved my charging problem.
I think that they know about this issue since one of the items in the upgrade package last year was a new cable.

[Radjack]

The bot came in just now and the charger stayed with a green light.

The cable issue sounds like a very real possibility, any idea what was wrong with the cable? Over the winter I made the cable longer, so there is now a splice in it... Since the voltages all remained the same I figured it was all good.

[mafster69]

I noticed the connections to the charging plates were crimped and then glued in place with silicone instead of soldered.
I thought this was the problem, but I can't be sure. The best clue I have for sure is using my winter charging cable charges fast and full.
The wire itself seems adequate, so that leaves added resistance at the conectors at one end or the other.

If you have a voltmeter, try measuring the voltage drop accross the cable while it is charging. If you see any appreciable voltage drop from the source end of the cable to the charging plates, there is abnormal resistance in the link.

[RobotLady]

Is the splice in the charger wire soldered?  If a new battery does not fix the problem, you might want to take a closer look at the splice.  Although the voltage is correct, the current could be getting restricted if the connection is poor.  You would still get a good voltage reading but the charge time will increase (similar to the behavior you are observing; so that's why I am mentioning it as a possibility).

[Radjack]

Filter is out of line and the run times have went up drastically with the old batteries....
I would estimate that the run time has gone up 30-40% from where it was when i started complaining.
Any one have more info on what this filter is doing, and if it serves any useful purpose in North America?
Should everyone be removing it?

I still havnt recieved the new battery from kyodo....
Will keep updating

[Botman]

The filter will remove interference with AM Radio waves.  If you are running without your filter, you or your neighbors will have trouble listening to the AM Radio.  Something seems amiss with your charger, because it should trigger a fast charge after running low.  I assume your mower is scheduled to mow daily?  Twice daily?  Good to hear you have increased runtimes...

[Radjack]

ya it is scheduled to run twice daily...
lack of AM radio...I dont think that will be a huge problem.

Just got the new battery from kyodo this morning...
I doubt it will react any differently but we will give it a try over the next few days.
The deeper we dig into this, the more i think it is simply the splice i have in that cable. If the resistance went up, that would mean the current would drop to the battery, therefore not providing enough for the battery to charge. I will have to do some testing to see...
will keep updating

[RobotLady]

"Over the winter I made the cable longer, so there is now a splice in it... Since the voltages all remained the same I figured it was all good."

This is the source of the problem.  There is resistance in the cable, this creates a voltage drop across the cable.  The voltage will never get higher due to the resistance.  The only way to solve it is to reduce the resistance.  It could be how the splice is soldered, it could be the wire itself.  Fatter wire will have lower resistance.

The upgrade included a fatter cable to the LB35XX charging base (this was not an issue for the other models).  The fatter cable reduces the resistance and allows the battery to charge higher.  If you did not get the upgrade, then making the cable longer increased the resistance even more.

Here is a tutorial on basic electronics so you can understand what is going on:

http://www.electronics-tutorials.ws/dccircuits/dcp_4.html

[Radjack]

I only made the cable longer by a foot or two, to reach the new base location. The length should not be an issue, but the splice might be...