Repairing an HS35 handset

May 17, 2004
5,032
Beneteau Oceanis 37 Havre de Grace
Had some trouble with our Simrad HS35 wireless handset that goes with our RS35 VHF. Others with the HS35 or its B&G equivalent H50 might have similar problems in the future so I figured I’d mention our solution. This really could solve two problems with the device - a rare software bug that leaves it unresponsive, or battery failure. Simrad has discontinued the model so there’s no easy way to just replace it other than an expensive VHF upgrade.

The problem started when we put the handset in its charging cradle and its distress light turned on, as if it were charging, but the little charge icon on the screen didn’t come on. We took it back off the cradle but the distress light stayed on, and we couldn’t turn it back on with the power button. None of the buttons, charging cradle, or USB charger seemed to do anything.

We figured we would try to disassemble the handset to see if its battery could be unplugged to reset it. Disassembly was pretty easy - just removing the screws around the perimeter on the back. Once open there’s a wire from the speaker that goes to a connector on the circuit board, and that connector can be pulled apart so the cover with the speaker can be separated from the body. Next there are 2 screws holding in the circuit board and display, so those can be removed, exposing the battery in the back of the device. At that point we got a surprise- the lithium polymer battery had swollen pretty substantially.

1634003077006.jpeg


The original battery was 850 mAH and fit in a recess that’s 48mm x 31mm. We were able to find a replacement on Amazon that 950 mAH and the same size. We spliced the new battery onto the old connector, hooked it all back up, and everything worked fine. There’s also a gasket around the perimeter. The easiest way to reinstall that is to place the gasket back in its recess in the front cover then put the two halves back together.
 
Jan 7, 2011
4,727
Oday 322 East Chicago, IN
Thanks for sharing that info.

i have the B&G equivalent. So far, no charging issues, but at times the handset seems to not change channels correctly. I was hailing a Laker ore boat on Lake Michigan the other day, and the skipper asked to go to channel 8…could not get my handset to change channels…kept changing to 3-channel scan or something.

Is your charging cradle mounted in the cockpit or at the nav station? my charger is at the nav station, where I charge it when not in use. I have thought about moving it out to the helm, but not sure I want to do that.

Greg
 
May 17, 2004
5,032
Beneteau Oceanis 37 Havre de Grace
Thanks for sharing that info.

i have the B&G equivalent. So far, no charging issues, but at times the handset seems to not change channels correctly. I was hailing a Laker ore boat on Lake Michigan the other day, and the skipper asked to go to channel 8…could not get my handset to change channels…kept changing to 3-channel scan or something.

Is your charging cradle mounted in the cockpit or at the nav station? my charger is at the nav station, where I charge it when not in use. I have thought about moving it out to the helm, but not sure I want to do that.

Greg
You might be able to disassemble it and clean the contacts under the buttons. Those are exposed after the front cover comes off. Also be sure you’re off scan before you try to change channels. While it’s scanning it just ignores channel changes. You need to press scan first to stop scanning, then channel change. Not necessarily intuitive when a big steel thing is coming at you.

We have the cradle in the cabin on a shelf near the nav station too. Earlier this year we bought an extra cradle from Simrad for the helm, because the battery wasn’t holding a charge quite as well. (They still sell the cradle at HS35 VHF Charger Cradle - 12V | Accessory | Simrad USA even though the handset is discontinued). We spliced the wires from the cradle into a 12V plug that we can plug into a jack on our pedestal. Although we just now found out that the handset has a USB jack on the bottom that you can charge it with, so if we had known that we could’ve just used a USB cable and a USB cigarette lighter plug for the helm.

I have read that the cradle isn’t rated for much water exposure, and the same is true of having the USB plug exposed, so neither is a great solution for rainy days, but for a brief charge in dry weather it’s fine. We were still getting about 8 hours from a full charge with the old battery, and with the new 950mAH one we’ll probably get through a whole day sail no problem, so not a common need anyway.
 
Nov 21, 2007
631
Beneteau Oceanis 34 Kingston, WA
Is your charging cradle mounted in the cockpit or at the nav station? my charger is at the nav station, where I charge it when not in use. I have thought about moving it out to the helm, but not sure I want to do that.
My charging cradle died a couple of years ago, took forever for B&G to have replacements available, but once they did they were reasonably priced and an easy replacement of the existing cradle. I think the new one came with quite a pigtail for the wiring connection, it should be easy to add one near the helm. I moved my dead cradle to the helm and use it as a holder for the handset, zip-tied onto a tube next to the chart plotter. I like the idea of having a charger out there, but I'm going to procrastinate until they are obsolete before I try to find another one. ;)
 
Jan 7, 2011
4,727
Oday 322 East Chicago, IN
Although we just now found out that the handset has a USB jack on the bottom that you can charge it with, so if we had known that we could’ve just used a USB cable and a USB cigarette lighter plug for the helm.
That is a good find! I will have to look at mine and see if has the USB port. That would work great.

thanks again.

Greg
 
Nov 21, 2007
631
Beneteau Oceanis 34 Kingston, WA
The USB port is what I used to charge mine for a year, when there were no charging cradles available.
 
Jun 6, 2022
3
nimbus 305 almere
Hi, I got probably a similar battery problem.

My remote HS35 stays only connected for 1 minute and then displays the message : searching…. It probably lost its connection with the RS35
Even (after clearing) registering again doesn’t solve this. Stays on register for ever…

My best guess is that my battery is on his end-of-live. The battery indcator however shows that the battery is completely loaded. So, has anyone an bright idea?

Maybe I should replace the inside lithium 3,7v battery anyway…

please give me your suggestions :)
 
May 17, 2004
5,032
Beneteau Oceanis 37 Havre de Grace
Hi, I got probably a similar battery problem.

My remote HS35 stays only connected for 1 minute and then displays the message : searching…. It probably lost its connection with the RS35
Even (after clearing) registering again doesn’t solve this. Stays on register for ever…

My best guess is that my battery is on his end-of-live. The battery indcator however shows that the battery is completely loaded. So, has anyone an bright idea?

Maybe I should replace the inside lithium 3,7v battery anyway…

please give me your suggestions :)
Replacing the battery could be worth a try, but if the icon still shows full I would guess that’s not the issue.

Did you update the VHF firmware without updating the handset firmware at some point, or vice versa? I know there were a few iterations of VHF firmware that required the handset to also be updated, or else they would lose their connection. The VHF could be updated over the NMEA network, but the handset could only be updated by a Navico tech, which made it a pain. We were able to get our handset updated by a Simrad tech at a boat show to keep everything sync’d.
 
Jun 6, 2022
3
nimbus 305 almere
Thanks for your update. Never did any updates ;). Tomorrow I will consult a local Simrad dealer…. I keep you posted…..

the thing what’s keeps me thinking…. Where did this connection problem came from…. Nothing was changed…. Therefore my best guess was that maybe the battery was on its end…
 
Jan 7, 2011
4,727
Oday 322 East Chicago, IN
I am getting ready to mount my cradle in the cockpit…but I almost ruined it when I tried to drI’ll out one of the mounting holes…the single one on the bottom. Turns out that there is a circuit board in that end of the cradle. It does have a hole in it for the mounting screw, but I made the hole bigger! It appears that the cradle still charges, but I need to seal it somehow before I mount it out in the cockpit.

I have been using the USB charger port for months and that works great.

I have never (knock on wood) had it lose the connection with the base station.

what if you keep the handset plugged in (either in the cradle or to a USB cord)…does it lose the connection to the base?


Greg
 
Jun 6, 2022
3
nimbus 305 almere
Hi Greg, I already tried it from the cradle , even with a connected usb wire. It refuses to connect.

But sometimes, mostly after a day when I activate the RS35 it’s somehow connected right away, but when you touch the buttons on the HS35 it loses connection and start searching again…. I also tried to erase possible existing connections from the menu. But the list was still empty.
 
Jan 7, 2011
4,727
Oday 322 East Chicago, IN
Hi Greg, I already tried it from the cradle , even with a connected usb wire. It refuses to connect.

But sometimes, mostly after a day when I activate the RS35 it’s somehow connected right away, but when you touch the buttons on the HS35 it loses connection and start searching again…. I also tried to erase possible existing connections from the menu. But the list was still empty.
Frustrating.

Greg