myHanse.com - Hanse Yacht Owners Website myHanse.com - Hanse Yacht Owners Website myHanse.com - Hanse Yacht Owners Website myHanse.com - Hanse Yacht Owners Website

Welcome to myHanse.com the forum for Hanse Yachts owners throughout the world.

Forum Home Forum Home > Hints and Tips > 445/455/458
  New Posts New Posts RSS Feed - Engine Battery Discharge
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Engine Battery Discharge

 Post Reply Post Reply
Author
Message
MrPotatoHead View Drop Down
Sub Lieutenant
Sub Lieutenant
Avatar

Joined: 08 April 2021
Status: Offline
Points: 16
Post Options Post Options   Thanks (0) Thanks(0)   Quote MrPotatoHead Quote  Post ReplyReply Direct Link To This Post Topic: Engine Battery Discharge
    Posted: 20 August 2021 at 16:09
Has anyone experienced unexplained battery discharge when away from the boat?  I have both service and engine batteries switched off but see a sudden drop from 12.8V to 12V on my engine battery over a 1 hour period.  This has now happened twice (but not always).


The drop occurs at about 6:00 AM with no one on the boat and everything off.  There is no evidence that the bilge pump ran during this time.
Hanse 458 #126
Back to Top
G8WVW View Drop Down
Commander
Commander
Avatar

Joined: 09 August 2019
Location: UK
Status: Offline
Points: 128
Post Options Post Options   Thanks (0) Thanks(0)   Quote G8WVW Quote  Post ReplyReply Direct Link To This Post Posted: 20 August 2021 at 19:01
Hi,

Cannot explain engine battery problem as your boat is newer than ours so not fully familiar with it.

The house battery isolator does not kill supply to everything. On our boat with house battery isolated, we still have power to VHF, AIS, VHF remote charger, bilge pump, Webasto heater, Fusion radio, Fusion WiFi adaptor and air-conditioning sump pumps; actually more than I would have expected!!

Could it be your heating?

Cheers.

Andrea & Ian
Aboard SV Gabrielle (H445 #164)
Portishead, SW England.
Back to Top
CrocDundee View Drop Down
Lieutenant Commander
Lieutenant Commander
Avatar

Joined: 12 December 2018
Location: Dundee
Status: Offline
Points: 54
Post Options Post Options   Thanks (0) Thanks(0)   Quote CrocDundee Quote  Post ReplyReply Direct Link To This Post Posted: 21 August 2021 at 10:09
Yes interesting puzzle. 

I would reinforce diesel heater as a possibility, but operating for one hour at an average of about 3 to 5 amps (allowing for startup and shutdown), should not take (even an engine battery) down 50% of its capacity. 

My additional suggestion to check is the engine battery may have diminished capacity. 

And finally, some unswitched loads may be on the engine battery, and some unswitched loads may be on the house batteries. I realised I do not understand which are on which even on our boat, and I have tried to follow these matters through and even tried a diagram. I assume our heater is on the house battery, and will check. Bilge pump will be interesting to know too. 
Hanse 345 - Tenacious. Sailing on the Solent and now to the west coast of Scotland.
Back to Top
MrPotatoHead View Drop Down
Sub Lieutenant
Sub Lieutenant
Avatar

Joined: 08 April 2021
Status: Offline
Points: 16
Post Options Post Options   Thanks (0) Thanks(0)   Quote MrPotatoHead Quote  Post ReplyReply Direct Link To This Post Posted: 23 August 2021 at 15:14
Thanks for the responses.  I do not have diesel heating and my AC/Heating runs off AC power.

Yes, it is surprising how many things run off the house batteries even when switched "off". I can also add the Sentinel system to that list.

I am leaning toward a battery issue. Either a bad battery or bad connection.  Next step is to isolate and load test.
Hanse 458 #126
Back to Top
CrocDundee View Drop Down
Lieutenant Commander
Lieutenant Commander
Avatar

Joined: 12 December 2018
Location: Dundee
Status: Offline
Points: 54
Post Options Post Options   Thanks (0) Thanks(0)   Quote CrocDundee Quote  Post ReplyReply Direct Link To This Post Posted: 23 August 2021 at 20:21
Good puzzle, so here is a complicated answer/hypothesis:

> Solar or battery charger on a timer, charge all batteries during the day
> During the night (chargers off), Sentinel and other loads deplete both batteries
> At about 6 am, on some mornings, the batteries are low enough in voltage (most are programmed to do this at about 12.9V) that the Battery Voltage Sense Relay (or ACR) automatically separates House and Engine
> The Engine battery is in poor condition and self discharges (12.8 to 12.0V)
> The Sentinel and all other unswitched loads continue on House battery
> Solar or timed charger switch back in during the day and voltage rises to 13.3V when VSR combines again with Engine battery and charges both together.

Accepting I might be over-thinking this. I will post the schematic of our boat below. We have a Victron GX system that allows remote monitoring, and I can understand the system behaving like this as it uses about 200 mA continuously. 
Hanse 345 - Tenacious. Sailing on the Solent and now to the west coast of Scotland.
Back to Top
CrocDundee View Drop Down
Lieutenant Commander
Lieutenant Commander
Avatar

Joined: 12 December 2018
Location: Dundee
Status: Offline
Points: 54
Post Options Post Options   Thanks (0) Thanks(0)   Quote CrocDundee Quote  Post ReplyReply Direct Link To This Post Posted: 23 August 2021 at 20:23


Edited by CrocDundee - 23 August 2021 at 20:31
Hanse 345 - Tenacious. Sailing on the Solent and now to the west coast of Scotland.
Back to Top
MrPotatoHead View Drop Down
Sub Lieutenant
Sub Lieutenant
Avatar

Joined: 08 April 2021
Status: Offline
Points: 16
Post Options Post Options   Thanks (0) Thanks(0)   Quote MrPotatoHead Quote  Post ReplyReply Direct Link To This Post Posted: 04 October 2021 at 22:41
Load test revealed that I have a bad battery.  It is just self discharging at a very high rate.  I also used a current clamp meter to verify there is no unexplained current flow.  The battery is less than 12 months old and supposedly still under warranty.  We'll see if this gets resolved....
Hanse 458 #126
Back to Top
Iris View Drop Down
Sub Lieutenant
Sub Lieutenant
Avatar

Joined: 03 July 2021
Location: Croatia
Status: Offline
Points: 6
Post Options Post Options   Thanks (0) Thanks(0)   Quote Iris Quote  Post ReplyReply Direct Link To This Post Posted: 13 October 2021 at 17:44
Hi ,on this schematic you show the charge controller connected to both the service batteries and the VSR. Is it connected like this or does the solar power go to the VSR first?I thought (but am not sure) that charge sources went via the VSR(or similar)and that “sorted” out which batteries needed charging.I ask because I temporarily connected demountable panels direct (via controller & protection)to the service bank but want to add a permanent panel to keep all batteries topped up over winter and rather than add another device I thought there was already something in the system that takes care of this when using alternator/ shore power as a source?
Back to Top
Matt View Drop Down
Captain
Captain


Joined: 08 March 2014
Location: New York, USA
Status: Offline
Points: 199
Post Options Post Options   Thanks (0) Thanks(0)   Quote Matt Quote  Post ReplyReply Direct Link To This Post Posted: 13 October 2021 at 20:10
On my boat I connected the panels as you suggest: panel to controller to house bank. Somewhere in the system are battery to battery connectors that charge the starter and bow thruster batteries from the house bank. Works a treat.

I use a remote monitoring system from Siren Marine (similar to Sentinal system) with all batteries individually monitored and have been able to see the charging across the three banks.

Re all the systems that remain live with the 12v system turned off. It’s easy to change things to switched, just a matter of changing the location of the Wurth plug on the DC distribution panel if that’s the system you have. Only a couple of the plug banks are unswitched.
HANSE 445 #231 "ALBION"
Back to Top
CrocDundee View Drop Down
Lieutenant Commander
Lieutenant Commander
Avatar

Joined: 12 December 2018
Location: Dundee
Status: Offline
Points: 54
Post Options Post Options   Thanks (0) Thanks(0)   Quote CrocDundee Quote  Post ReplyReply Direct Link To This Post Posted: 13 October 2021 at 20:41
I think it is drawn correct for our boat. AC charger and solar charger are on the unswitched House battery side and engine alternator is on the Engine battery side. 

The VSR connects both when one voltage is higher than 13.4 (about) and disconnects when both batteries drop below 12.9. There is a delay to ensure it does not click in and out. 

So this works well, and one can see the delay on either side when you are working with depleted batteries and charging from either side. After sailing for an hour, the engine battery is at 12.9, house batteries at 12.6. Start the engine, and alternator charges the engine battery for about a minute, before it switches in to charge the house batteries. I have watched the voltages and heard the engine note change as the alternator gets more work to do. 

Similar process, but starts on the house side, when we plug into AC. 

I am interested if my understanding can be improved. Our system is simpler in that it does not have additional batteries. 
Hanse 345 - Tenacious. Sailing on the Solent and now to the west coast of Scotland.
Back to Top
 Post Reply Post Reply
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.01
Copyright ©2001-2018 Web Wiz Ltd.

This page was generated in 0.094 seconds.

Links : www.hanseyachts.co.uk www.hanseyachts.com www.fjordboats.co.uk www.dehler.co.uk www.varianta.co.uk