Autohelm Power Consumption
Printed From: myHanse.com
Category: Hints & Tips
Forum Name: 345/348
Forum Description: 345/348 Hints, Tips and News
URL: https://www.myhanse.com/forum_posts.asp?TID=13420
Printed Date: 27 March 2026 at 03:29
Software Version: Web Wiz Forums 12.06 - https://www.webwizforums.com
Topic: Autohelm Power Consumption
Posted By: Mike58
Subject: Autohelm Power Consumption
Date Posted: 04 June 2022 at 13:54
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I have just finished a couple of longish trips cross channel - UK to France - in F5 and lumpy seas. The auto helm drained the batteries after about 4 hours and I had to resort to putting the engine on tick-over to top them up. Has anyone had a similar experience. Would fitting solar panels solve the problem? I have looked at settings to reduce the auto helm workload but that has not had much impact. ------------- Mike L |
Replies:
Posted By: High Time
Date Posted: 05 June 2022 at 14:29
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Hi Mike Are you sure it's not a battery issue, rather than the autohelm? How old are the batteries and what capacity is the service battery (bank)? Also, are you sure they were fully charged at the start of the channel crossing? The autohelm can take 5A or more when it is operating so if it was running continuously (which it shouldn't be in a well balance boat) it would consume approx 60Ah in a typical channel crossing. This should not flatten an otherwise good condition, fully charged AGM battery (165Ah capacity?) but it would reduce the voltage to the low 12s. ------------- Roger High Time (415 #038) |
Posted By: Mike58
Date Posted: 05 June 2022 at 15:19
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Roger - many thanks for the detailed reply. I picked up the boat new in May 2020. The boat is key alongside at an MDL marina permanently connected to shore power. I had therefore assumed that the batteries were okay. However what you say makes sense and perhaps either the life of the battery or having them permanently connected to shore power has degraded their performance. ------------- Mike L |
Posted By: Mike58
Date Posted: 05 June 2022 at 15:21
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Roger - following up on your comment. The battery level is falling to 10.7V from a starting point of 14V. ------------- Mike L |
Posted By: 415 Singapore
Date Posted: 06 June 2022 at 07:41
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Hi Mike Assuming you have AGM batteries, I am sorry to say if your batteries weren't stuffed beforehand they certainly are now! How big is your battery bank and how old are the batteries? Being permanently connected to shore power shouldn't cause an issue as the battery charger should change to a trickle charge once they reach an optimum voltage. Our last AGMs lasted about 5 years but were losing their charge very rapidly towards the end. Good luck Paul ------------- Paul - Night Train - 415 #136 |
Posted By: Mike58
Date Posted: 06 June 2022 at 14:00
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Hi Paul I took a read out from the battery manager Chargemaster 12/35-3 and looking at Amperage it was on the 2nd bar from bottom (40%) even after it has been attached to shore power for 48hrs. So it feels like it is the battery. The boat was delivered to me new in May 2020. But of course there is no telling how old the actual batteries are. ------------- Mike L |
Posted By: 415 Singapore
Date Posted: 06 June 2022 at 14:40
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Wow, they should last longer than two years, unless you have allowed the voltage to drop very low at some time. Maybe worth getting the charging system checked out at the same time. Good luck Paul
------------- Paul - Night Train - 415 #136 |
Posted By: CrocDundee
Date Posted: 12 June 2022 at 16:48
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While your (newish) battery bank may be sub-optimal as discussed above, you may also be just seeing a genuine behaviour of running lots of electric while underway. We have new Victron service batteries on our H345 (320 AH) and extensive monitoring via a Victron shunt and a CCGX. When you add up the auto-helm, (following sea is hard work), instruments, fridge(?), add a few phone/computer chargers, radios etc, and the battery capacity can get used significantly. And we only have a usable capacity of 160 AH, at 50%. And yes solar panels (200W deck mounted) help a lot. We can run power neutral with the auto-helm, countless instruments, fridge etc, during the day in summer in Scotland. To test your service batteries charge them up then measure the voltage drop via a known load. Instruments + steaming light + all interior lights + VHF radio will probably use about 6 amps. Monitor battery voltage for 5 hours, 10 hours, 15 hours, 20 hours. Don't take the service batteries lower than about 11.5V when under this load (IMHO). ------------- Hanse 345 - Tenacious. Sailing on the Solent and now to the west coast of Scotland. |
Posted By: Mike58
Date Posted: 12 June 2022 at 16:53
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Done the battery tests and sadly the batteries are done for. I suspect my own fault in running them too low when at anchor during the past season. Now investigating replacement and whether to bankrupt the savings with lithium batteries. ------------- Mike L |
Posted By: CrocDundee
Date Posted: 12 June 2022 at 17:20
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Oh dear. I have used both Tayna and BatteryMegastore for replacements. I see Tayna more reasonable at present, and the Victrons we purchased recently from BM have increased by £100 each (!). Forget Lithium I suggest, unless you wish to spend an awful lot professionally, or become an enthusiast with many hours of study and refitting a wide range of electrical components on the boat. ------------- Hanse 345 - Tenacious. Sailing on the Solent and now to the west coast of Scotland. |
Posted By: Martin&Rene
Date Posted: 16 June 2022 at 21:50
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To help keep the batteries at a decent charge level during trips, I installed a Sterling Alternator to Battery Regulator and this seems to do an effective job given our normal mix of sailing (preferable) and motoring (avoided where possible). I have some notes of what I did wrong and what I did right. ------------- Martin&Rene Hanse 341 Dipper Wheel steering, 3 cabin layout, normally based in Scotland |
Posted By: Tranquillity
Date Posted: 16 June 2022 at 22:07
| Mike, We had a similar issue batteries running low but after an 8 hour channel crossing to Alderney in F5. The lesson we learned was to monitor the batteries as autohelm takes a good 5A in big seas combined with fridge and everything else soon adds up. We have a Pico monitor but very interesting to monitor the draw and by turning off fridges etc on long passages how battery life is extended. We have learnt that no less 88% keeps above 12.3v. |
Posted By: Mike58
Date Posted: 16 June 2022 at 22:59
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Many thanks for comments. I am having a monitor fitter to try and work out what current is being drawn. My sense is that the batteries are done for. At anchor with just fridge running they go from 14v to 11v in 4-6 hrs. Looked at lithium options to replace but £3k+. Want to double check there is no unknown draw on batteries before I change them as they are just 2 years old. ------------- Mike L |
Posted By: S&J
Date Posted: 17 June 2022 at 05:57
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I strongly advise getting a battery monitor, either the Victron Bluetooth shunt it even a cheaper NASA BM1. These will tell you the battet voltage (at the battery rather than elsewhere) and total current draw. By switching things on and off you can easily learn how much power each device really uses, but note that autopilot and fridge will not have constant current draw. AGM batteries should not be depleted below about 75% if you want them to last Note this means you can generally only use 25% of the stated capacity. If you have a single 160Ah battery this is 40Ah or 480W. Double that if you have two X 160A. In addition to the autopilot, your fridge is also a high consumer. I generally find I use an average of 8A when sailing with autopilot, fridge and all instruments. I had a 100W solar on my 385 which could "just about" keep pace with this in ideal conditions but was useful for recovery once at anchor. My main issue was (and still is, even with a 480Ah bank) sailing overnight which can bring the batteries down to the 75% capacity level, requiring a bit of a boost from the engine to recharge. ------------- H458 #159 Primal Mediterranean cruising |
Posted By: Matt1
Date Posted: 17 June 2022 at 11:57
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I fitted an old BEP monitor - it’s basic (which suits me fine!). Was quite surprised recently after a 9hr sail (under autopilot) & night at anchor that with normal electronics, anchor light and fridge, by the following morning I was at around 160-170amps remaining. I’d been lazy using the electric winches to put a couple of reefs in but was still surprised when the alarm went off for me to recharge. I have a 120w solar panel which normally keeps up with the autopilot demands in daytime. ------------- Hanse 418 #64 EmBer. Hamble, UK |
Posted By: Mark_J1
Date Posted: 18 June 2022 at 10:42
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Matt I’d urge you to look hard at LiFePO4 batteries if you have to replace anyway. The swapover isn’t as complex as many make out and the value over time & in day-to-day use is ultimately better than any kind of FLA or AGM alternative. In use you’ll find the battery voltage stays higher (ie less sag under load), they recharge faster if you do happen to run the engine etc etc. Be realistic about surveying your power demand underway. It can easily be an average 10Ah with fridge, instruments, radar, AP, phone recharge etc etc. You’ll find the available draw from a LiFePO4 bank is much greater for an equivalent size. That said, anything you can do on the input side is a help. Solar, water generator etc can make a significant difference. I’ve just got to the point where at this time of year I have enough input power to dump a little power to the calorifier element (via a ‘speed controller’ to reduce the power draw). So even get hot water without engine or shore power. So even the admiral is happy :) Mark ------------- Hanse 400e "Grey Goose" Hull #31 |
Posted By: Mike58
Date Posted: 18 June 2022 at 12:27
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All - many thanks for some extremely helpful responses. I have neglected power management and now paying the price (literally) for that with two dud 160AH AGM batteries that are only two years old. Over the next couple of weeks I will need to sort out as I am cruising to the Channel Islands. Just spent two nights at anchor off Newtown Creek and the batteries went to dead that I lost all electronics despite being fully charged 6 hours previously. Volt meter read 10V. ------------- Mike L |
Posted By: H8jer
Date Posted: 18 June 2022 at 12:30
How many batteries you have now? To convert to Lipofe4 you need: • LeadAcid Starter battery always visible for the alternator. • Battery isolator e.g. Sterling ProSplit • X times something like https://uk.renogy.com/12v-100ah-smart-lithium-iron-phosphate-battery/" rel="nofollow - https://uk.renogy.com/12v-100ah-smart-lithium-iron-phosphate-battery/ (Check the height of battery, Hanse use low height battery.) • Shore Charger with lifepo4 program or manual set to 13.8v • check that all cables are thick enough to handle the current. Don't think you end up on £3k+ ------------- Hanse 370#487 30HP 3-cabin |
Mike58 wrote:Posted By: Mike58
Date Posted: 18 June 2022 at 13:09
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I have 2 x 160AH AGMs that are connected to a Mastervolt Battery Management System. In addition I have a LeadAcid for starter engine and one for bow thruster. All managed off the BMS. £3k+ came from 400AH Mastervolt Lipofe4 - £3995 from google search. Then fitting batteries with need for isolator switch and recabling - cables for these batteries to maintain warranty need to be of the same length - exactly. Mastervolt will not cover any batteries fitted that are not from them in terms of indemnity against fire or other battery related accident. Alternative is to fit 2 x 100AH Mastervolt at £1229 ex VAT each. So cost soon ramps up. ------------- Mike L |
Posted By: Mike58
Date Posted: 18 June 2022 at 18:14
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Has anyone installed an EFOY Fuel Cell system or something similar? ------------- Mike L |
Posted By: Matt1
Date Posted: 18 June 2022 at 18:29
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There’s a 418 owner on the 418 owners FB page who is about to install an Efoy - I’m interested to follow. Patrick Laine of YouTube fame seemed happy with his. If / when I go extended ocean sailing this or probably a watt n sea will be what I opt for. Bother about the same price eg £££££££ I’d want to understand how Efoy’s degrade over time ------------- Hanse 418 #64 EmBer. Hamble, UK |
Posted By: Mike58
Date Posted: 18 June 2022 at 18:55
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Just looked at the video. EFOY seems to have a 5000hrs cycle life. It is cheaper than the Watts depending on which model you have fitted. The stern mounted is cheaper but it may only work efficiently on a certain tack. You can get it mounted under the boat but a little more expensive. And only works if you are moving. Whereas the EFOY is still charging at anchor. ------------- Mike L |
Posted By: Mark_J1
Date Posted: 18 June 2022 at 19:20
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For Mike & anyone else contemplating the LiFePO4 battery jump - re LiFePO4 cost. My own experience is as follows. I currently have 2 x 150AH for a total of 300Ah ( so 240AH usable to 80% DOD) for a cost of £655 each with configurable JBD Overkill BMS and Bluetooth connection for management. Add a couple of hundred more for a programmable relay to sort connectivity with the alternator, plus revised cabling. I did have a DC-DC charger in the mix initially to manage alternator load but ditched it as it introduced complexity and my 400 already has more than enough resistance in the cables to keep the alternator ticking along happily at a max of 61A and a temp of 55-70C. My existing Sterling 3 way charger set to Gel settings is providing the charging at 14.1-14.3v that LiFePO4 is happy with. I may yet add a 3rd LiFePO4 battery to give a total of 450AH but I still wouldn't hit £3K. Mark ------------- Hanse 400e "Grey Goose" Hull #31 |
Posted By: Mike58
Date Posted: 18 June 2022 at 19:27
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Mark - which Lithium batteries (make) did you buy? ------------- Mike L |
Posted By: Mark_J1
Date Posted: 18 June 2022 at 21:23
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Mike I went with the ones from LifeBatteries. UK firm with a knowledgeable guy running it. Also called Mark by chance, no connection! Link to what I bought below. Mark https://www.lifebatteries.co.uk/product-page/150ah-lifepo4" rel="nofollow - https://www.lifebatteries.co.uk/product-page/150ah-lifepo4 ------------- Hanse 400e "Grey Goose" Hull #31 |