13313Re: Which brand and type of batteries are used in the current RL1000 models
- Jul 31, 2007I measured all the voltages, 11.1 and 11.0V when the mower goes back
to the dock, 13.1 and 13.2V after the docking station is done
charging. I suspect that the charging algorithm is not very good for
SLA type batteries (it uses a constant charging current of about 1A
and a voltage limit of 28V). In my mind the batteries don't get
charged well under these conditions (manufacturers recommend way
higher charing currents and constant voltage chargers). In addition
the charging is interrupted if the FET is getting hotter than 125°C,
which happens frequently. It will restart the charging when the
temperature gets below 110°C. Manufacturers recommend to charge the
battery w/o interruptions until it is full.
ALso: The battery pack gets too hot during charge due to sun exposure
of the mower and the vibration of the mower are not good for SLA
Just my 2c, I will buy a original replacement pack since they give
you a 1 yr warranty.
--- In RoboMower@yahoogroups.com, Christopher Zach <cz@...> wrote:
> I'm really curious as to all these battery problems. Partially
> my 500 Robomower is using packs that are several years old and
> gets >2 hours per charge.
> Has anyone hooked a meter to one of these packs and watched it when
> mower poops out? What happens to the voltage on each battery? Is
> sagging low under load? Do they both sag? Is one reading 10 volts
> the other reading 12?
> How about on charge? When the mower says "full" are both batteries
> 14 volts? Do they have a nice 13.0 volts at rest? How about when
> first start charging? Is one still at 12.8 while the second drops
> 11.0 right out of the gate?
> Something here doesn't make sense.
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