Raymarine "Smart" controller

BobE

BobE

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In a moment of weakness (won on the GGs) I invested in a Raymarine Smart Controller. (the wireless type)
It works fine and will steer the old girl from the bow.
But I'm a bit wary of leaving it plugged in on permanent charge (Cigar lighter socket).
If I've not been on the boat for a time, say 14 days, the inbuilt battery scale shows that it has lost charge although it's been switched off. Of course I can still use it plugged into the socket. But not from the bows when on Lobsterpot lookout!
I found this interesting Sailing Forum thread.

http://forum.ssca.org/phpBB3/viewtopic.php?f=4&t=12922

Which finally claims that the batteries are simply 2 x AA 1.2v 1600mAh nickel metal hydride.
from the thread it appears that they are in series. (One of the poster's writes about 2.6 v
when "Off Charge")

Has anyone found anything out about the things??

No info. as to power sources and battery replacement on the Raymarine site..
If I take the plunge I'll take photos for posterity!

Finally advice on whether it would, if the forum post is correct, be OK to use say 2500 mAh cells i/o the 1600 mAh mentioned???

Cheers Bob E..
 
From Wikipedia

Self-discharge
NiMH cells historically had a somewhat higher self-discharge rate (equivalent to internal leakage) than NiCd cells. The self-discharge varies strongly with temperature where lower storage temperature leads to slower discharge rate and longer battery life. The self-discharge is 5 – 20% on the first day and stabilizes around 0.5 – 4% per day at room temperature.[20][21][22][23][24] But at 45 °C it's approximately 3 times as high.[15] This is not a problem in the short term but makes them unsuitable for many light-duty uses, such as clocks, remote controls, or safety devices, where the battery would normally be expected to last many months or years. The highest capacity cells on the market (>8000 mA·h) are reported to have the highest self-discharge rates.[citation needed]
 
I've changed the cells on mine. Opening the casing (without damage) is the hardest part of the job.
I've used NIMH cells from a electronics shop in my town.
The point is that you require a set off cells with solderlips welded to the poles. If you are using normal ones without lips you are required to solder the tips of the battery. This may lead to damage on the battery because of too much heat applied to the electrode.
I'm not sure how bad this could get however.
I used the highest capacity I could get.

The real problem with this gadget is however that it never really shuts off. There is always some drain on the battery. This, combined with the self-discharge, makes the controller not the best thing for occasional use unless you keep it on the charge cable. But continuous charging of NiMH cells is also not recommended...

The annoying thing is that the simple version of this gadget works with plain AAA batteries that last quite a long time (months).

Cheers,

Arno
 
Battery level indicators

Electronic devices often use a simple volt meter to indicate battery level. This is not very useful for battery types like NICad or NiMh as these batteries by nature hold a pretty constant voltage until the last gasp. So if you get a low batt indication it is probably very low. A full indication means between 10 and 100%.
To overcome this problem some sophisticated devices use a cumulative milliamps in milliamps out indicator (like a BM10 battery monitor.) This has its own problems but tends to be more useful indication.
However this latter type does not take into account self discharge.
I would suggest to the OP that he does not leave it on charge long term. But recharge on arrival at the boat for hopefully a period which will recharge the batteries enough for the service needed then put on charge again before departing the boat. Or charge it from a circuit controlled by main battery switch so turned off on leaving the boat.
Incremental readings of battery charge IMHO is not reliable on any device. Only when it stops can you be sure battery is flat. Only after a long charge can you be sure that is the best the battery can give.
Replacing with larger batteries should give more charge current and longer life but as said more self discharge. I wouldn't bother until original batteries are dead.
good luck olewill
 
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