LB3510 Not charging

[LAGbot]

I'm having trouble getting the Lawnbott going this spring:  voltage on display reads 2650-2660.  I have done the following:
- Cleaned the charging plates and nuts with sandpaper and steel wool
- Unplugged/plugged the battery from the motherboard
- Removed/inserted the 20A fuse
- Removed/inserted the wires into the charging base
- Unplugged/plugged the power supply

I did charge it monthly over the winter to keep the batteries conditioned, and I've had it for 3 seasons (this will be the 4th).  Could the batteries be dead?

[Botman]

Doubt the batteries are bad. I am on my 10th year with mine (knock on wood).

Did you clean the posts after removing the dome nuts?  I've needed to clean them periodically. Also check the voltage at the plates with the mower out of charger. Should read 29.3 volts. You could use your winter charger to see if it charges. Then you can troubleshoot if it the mower or charging system.

Also if your voltage at the plates is less than 29.3. Check the voltage from the signal generator. When you unplug it from the cable that goes to the charger look at the the wires and remember which pin goes to the black and red wire. The voltage there should be 29.3.

If you use a signal filter remove that from the chain because it can be a source of problems.

[LAGbot]

I am getting 29.3 volts at the charging plates, so I think everything is working right up to that point.  I have not cleaned the threaded posts, so I'll try that.  Next step will be new dome nuts:  The chrome is worn away, so they oxidize pretty quickly now.

[moti]

This thread is timely, because moti is only getting about 30 minutes of work time on each charge. When I looked back through the forum posts, I saw that I complained about this same issue in 2015 but it must have corrected itself. I am encouraged by any reports of long battery life (moti's batteries are 2012) so I'll take your advice and clean the plates and post caps. Then I'll report back.

[Botman]

Also check if your charger enters rapid charge mode when the bot returns to the charger.  The light on the battery charger will be red instead of green (if the voltage is low).  I've had problems with the bot returning to the charger with only 2600 on the readout and it doesn't enter rapid charge mode so it will only increase by 50 points before the next mow (using general numbers for example).  Cleaning up all the contacts seem to correct the problem.  Also I remember in the service manual a setting to force the bot to always rapid charge - but I would want robotlady's input on that one before changing that setting.

Another pattern I have noted, but not sure if it is real is that these problems tend to occur for me in the spring and fall so I am not sure if ambient temperature can play a role.

[RobotLady]

Ambient temperature can have an affect, but more likely it's something like dull blade, charge contacts, etc.  If you let it go fully dead, even one time, it will affect run time, but just keep running it - eventually it will recover.

Cleaning oxidation off the charge base contacts needs to happen each Spring.

We have recently posted troubleshooting guides and Winter Service information here:

http://www.paradiserobotics.com/dealer-information

There is a "Short Run Times" troubleshooting guide and others, also.  Even clogged wheels will impact run time.

As for "service menu rapid charge" in the service menu, I have not heard of that setting before.  I would have to investigate it and report back.

RobotLady

[LAGbot]

My problem last year was solved by replacing the charging nuts. The old ones were too far gone that polishing with sandpaper wouldn’t help. The coating was gone and they would oxidize quickly. I ended up replacing them with stainless steel dome nuts from Home Depot.

This year I had a new problem. I brought the mower out from hibernation with a fully charged battery and it started right up and mowed for several hours. However, when returning to charge, it wouldn’t stop in the base...it would drive right through. When I turned it off and placed it in the base then turned it on again, it would stay paused and wouldn’t start charging. I cleaned up the charging plates and the charging nuts to no avail. Then I went the clean the threads on the charging posts and noticed the black wire to one of the posts was broken. It seems to have degraded over time and just snapped. I repaired it: stripped the two ends, soldered and coated the joint with liquid electrical tape.  Good to go now!

[Botman]

LAGbot I had the same problem occur but mine was caused by a small pinecone which had worked its way between the hood and the chassis.  The pinecone eventually rubbed the wire and broke it.