B&G Halo 20 radar issue - why does it automatically shut down when boat stops moving??

[Pleinmont]

Thanks Paul. I left them both charging on shorepower last week and after a couple days went back and they were both on float at 13.4v when I disconnected the shorepower. After an hour they were both showing full at 12.8v.

But was disappointed to see that they were down to 12.5 the next day when we went out.
Then as before, after 20mins journey the leisure batt dropped volts again and the radar was shutting off.
Alternator is charging them just over 14v when underway btw which seems ok and I've not had any issues starting the boat.

So it seems the leisure battery has had it (the cranking battery seems ok).
I have learnt my lesson and will keep a new leisure battery (and the cranking batt) topped up on shorepower (or a solar panel trickle).

Question is, should I look for a more suitable battery for the house/leisure next time? I can't afford Li-Ion btw
I currently have two of these.
YBX1627 - YBX 1000 SHD - Commercial Vehicles - Batteries

 

[h20man]

Thanks Paul. I left them both charging on shorepower last week and after a couple days went back and they were both on float at 13.4v when I disconnected the shorepower. After an hour they were both showing full at 12.8v.

But was disappointed to see that they were down to 12.5 the next day when we went out.
Then as before, after 20mins journey the leisure batt dropped volts again and the radar was shutting off.
Alternator is charging them just over 14v when underway btw which seems ok and I've not had any issues starting the boat.

So it seems the leisure battery has had it (the cranking battery seems ok).
I have learnt my lesson and will keep a new leisure battery (and the cranking batt) topped up on shorepower (or a solar panel trickle).

Question is, should I look for a more suitable battery for the house/leisure next time? I can't afford Li-Ion btw
I currently have two of these.
YBX1627 - YBX 1000 SHD - Commercial Vehicles - Batteries

LiFePO4 batteries appear to be expensive.. yet, the performance and longevity inherent in the technology (in my opinion) make up for replacing cooked/run-flat lead acid (or AGM) batteries...
If one has the technical experience, building a system with BMS and reputable cells... then it is even more compelling..

 

[Pleinmont]

I've definitely not got the expertise to build my own or the cash to buy a lithium one so looks like a lead acid or AGM for me

Is there a preference for AGM or lead acid for leisure/house batteries?

 

[PaulRainbow]

I've definitely not got the expertise to build my own or the cash to buy a lithium one so looks like a lead acid or AGM for me

Is there a preference for AGM or lead acid for leisure/house batteries?

In your case, i don't think you will gain much by paying the extra for AGM and Lithium would be a total waste of money. Some of the Lithium lovers would have you fit them to a dinghy

Not sure that the truck battery is the best choice, could you squeeze a couple of smaller leisure batteries in ?

 

[Pleinmont]

Thanks for the advice Paul. Much appreciated. Yes, been doing a bit of background reading and agree - think I'll stick with lead acid for now and replace the sick leisure battery (keeping them topped up this time with shore power when not on the boat).
I've got space for two truck batteries as in the pic below of the Antares 760 battery box under the stairs (not my boat but my 760 is the same setup) - briefly what would be the benefit of 2 smaller batteries rather than a large single leisure?

Also, I was worried about galvanic corrosion leaving the boat on shore power all the time so just used to charge the batteries when using the boat (which if left for a few weeks was in hindsight no good for the batteries).

Being simplistic, would fitting a basic galvanic isolator like the Zinc Saver make it safe to use shore power most of the time and not have to worry about the anodes disappearing much faster than normal etc.
Zinc Savers / Galvanic Isolators
Or even easier... a plug in one?
Galvanic isolator - Plug In - 16amp - Easy diy installation - UK made.

 

[PaulRainbow]

Thanks for the advice Paul. Much appreciated. Yes, been doing a bit of background reading and agree - think I'll stick with lead acid for now and replace the sick leisure battery (keeping them topped up this time with shore power when not on the boat).
I've got space for two truck batteries as in the pic below of the Antares 760 battery box under the stairs (not my boat but my 760 is the same setup) - briefly what would be the benefit of 2 smaller batteries rather than a large single leisure?

The truck batteries are meant for heavy discharge over a short period, they are big and heavy too.

Also, I was worried about galvanic corrosion leaving the boat on shore power all the time so just used to charge the batteries when using the boat (which if left for a few weeks was in hindsight no good for the batteries).

Being simplistic, would fitting a basic galvanic isolator like the Zinc Saver make it safe to use shore power most of the time and not have to worry about the anodes disappearing much faster than normal etc.
Zinc Savers / Galvanic Isolators
Or even easier... a plug in one?
Galvanic isolator - Plug In - 16amp - Easy diy installation - UK made.

Plenty to choose from here ; Products Archive - Galvanic Isolators

But, you only need a galvanic isolator if your shore power Earth is connected to your anode.

 

[Pleinmont]

Many thanks Paul
Ok, that makes sense.
Will have a look for a more appropriate house battery(s) (the current two truck batteries were just provided by an electrician to replace the old ones - we never had a conversation about house vs cranking).
In fact I never checked the old pair to see if they were different - ie one for cranking and one for leisure.

Re galvanic isolators - I might well benefit as I believe my stern gear/rudder anode/prop shaft etc are all bonded / earthed.
There's an earth wire connected to the rudder stock in the stern lazarette and the gearbox also has an earth cable from the engine (as do the two inlet seacocks for stern tube and raw water).
I have anodes on the rudder, propeller and the skeg all of which would appear to have connections back to the engine and 12v/240v electrics system.

Thanks, again, this is all good stuff.
You live and learn (esp with YBW)