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raymo
United Kingdom
322 Posts |
 Posted - 03 Jul 2009 : 22:13:34
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we have 2 leisure batteries 110 ah each and a starting battery 90ah,also a large solar panel,and a three way switch, all the wiring appears to have been very well executed and all is in good nick and all seems to be of a good quality,however i am totally clueless about electrics(our previous boat had one 90ah for both starting and lights etc).this wonderful setup has one fatal flaw ie i am ignorant as to how to use it to its best advantage.
hence the request, i need an absolute morons guide to what i assume is a 1/2/both switch,in respect to charging from the engine(honda15hp),the trickle charge from the solar panel,and best use when the batteries are charged! (engel fridge,5amp tv,lights)
all comments both mocking and helpful welcome.
as ever many thanks in advance.
raymo. |
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golligy
United Kingdom
55 Posts |
Posted - 03 Jul 2009 : 23:01:53
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Assuming both your leisure batteries are chained together on position two and the starting battery on one position one then you should start the engine on one then you have a multitude of options-
-Leave it on one and charge the starting battery
-switch onto two if you have been using your leisure batts over night moored up.
- Turn it to both which is fine if both batteries are in a reasonable state of charge.
The problem with these switches are that you must remember to switch them over when you Moore up (although you can start from the leisure in an emergency) and it makes it harder to have a diode splitter to sense the battery state so not to over charge.
On my last boat each battery had its own cut off switch coming from the splitter to each battery, I am now on one of these three way jobs and I hope if I put the splitter onto the both option then this will enable proper charging. But I haven't tried this yet so maybe someone can confirm or deny? Anyway for now I would get a cheap multimeter and check the starter battery after 15 minutes running if its full then switch to the leisure bank as this will obviously take more power. |
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adi-n-chez
United Kingdom
1980 Posts |
Posted - 03 Jul 2009 : 23:14:39
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Raymo
Like yourself always only had one battery ! (Have now added a 110 Leisure to be wired tommorow!)
I plan to use the 70amp diesel batt (Original) for starting & the leisure batt for night use for Chez's new ASDA tv !
Like you we have a Honda BF15 so minimal (8amps ?) charging. I will run with switch on 'both' during the day hence charging both , then switch to No.2 for night use so keeping starter fresh.
To be fair never had a prob with flat batts even with only 1 , we do cruise fairly well tho  , Even if we suffered low batts (Start of season) we can always pull start the honda.
Dad has 2x 110amp batts on his Sewer tube. Switching 1 off at night ensures he can start his smoky BMC , while the other runs domestic lights & the tv (He doesnt cruise as much but benefits from the extra charging of the inboard)
Not sure on the draw of yr fridge - Is it heavy ? this could denote if you have to run on 2 batts at night
Adi
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raymo
United Kingdom
322 Posts |
Posted - 03 Jul 2009 : 23:15:33
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many thanks for that goll,now that actually makes sense to me,just to clarify though,you assume starter on 1 and leisure on 2, is that purely an assumption,or is that the accepted/usual way of doing it?
raymo. |
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raymo
United Kingdom
322 Posts |
Posted - 03 Jul 2009 : 23:28:21
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cheers adi, i think i am getting the hang of this,now assuming that my setup is the same as golls'then if i start on 1 then i can switch to either 1/2/ or both for charging but when i moor up i should switch to 2 for overnight then back to 1 to start up and back to 2 with engine running to recharge both? phew !
raymo. |
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adi-n-chez
United Kingdom
1980 Posts |
Posted - 03 Jul 2009 : 23:43:15
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Sounds about right Raymo !
Unless your fridge is heavy drain, I suspect that you will have no probs starting if you have left the swich on both (3 batts)
Hondas take little juice to turn over , On low batts on ours motor will try to start but the 7" tv wont work !!!
Adi |
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raymo
United Kingdom
322 Posts |
Posted - 03 Jul 2009 : 23:51:26
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| off to swot up on diodes ! |
Edited by - raymo on 04 Jul 2009 00:06:02 |
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TheBoatMan
66 Posts |
Posted - 04 Jul 2009 : 16:49:55
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| Re swithching batteries, Is it safe to switch from "one" to "two" or "both" when the engine is running, or might it damage the alternator? Are these switches normally "make" before "break" (presumably these would get aropund the problem of the alternator diodes getting zapped) |
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Fred
2007 Posts |
Posted - 04 Jul 2009 : 17:12:49
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quote:
Is it safe to switch from "one" to "two" or "both" when the engine is running
No, you could damage the alternator. Some of the more expensive switches are specified as 'alternator field disconnect' while switching and only these will be completely safe.
After using one for years I've recently come round to thinking that these switches are a waste of money, unnecessarily complicate the system and probably lead to some voltage drop anyway. You will inevitably forget to switch over just when it is most crucial. Spend your money on more battery capacity, put them all in parallel permanently and be sensible with power use. Whatever you do, you will be limited by the charging capacity available. Usually not a problem with an inboard but always a limiting factor with an outboard.
And diodes? You'll probably lose best part of a volt through the diode. When the batteries are low anyway that could easily make the difference between turning the starter and not. |
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golligy
United Kingdom
55 Posts |
Posted - 04 Jul 2009 : 21:06:06
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Most people put starter on one and the rest on two but makes no real odds. And I agree the switch does make things more complicated but according to the second edition bss all inland craft will have to comply to-
(http://www.boatsafetyscheme.com/site/2ndedBSSEssentialGuide_212.asp)
all batteries must have the capacity to be completely switched off or disconnected. I have yet to find out if you could use the answer I just pull the wire off but I doubt it. As for switching whilst running strictly you shouldn't but I never had any worries with it but split relays or diode would save the bother. Check out asap supplies for them they are **** hot on knowledge and reasonably priced. |
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golligy
United Kingdom
55 Posts |
Posted - 04 Jul 2009 : 21:09:39
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| Ps I don't know where you are but the Norfolk broads have just made it so you cant get your toll without a current bss cert and there is talk of compulsory minimum of third party insurance and these tend to like you to hace a certificate for obvious reasons. They will get your money one way or another. |
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Fred
2007 Posts |
Posted - 04 Jul 2009 : 22:02:04
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Don't confuse a changeover switch with an isolator switch. An isolator switch for all battery banks is compulsory for BSS. A changeover switch isn't, although most changeover switches have an ALL OFF position that acts as an isolator.
.... And 'I pull the wire off, guv' won't count because the switch has to be easily accessible (or in a clearly marked position), close to the batteries, complete and in good condition. |
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adi-n-chez
United Kingdom
1980 Posts |
Posted - 05 Jul 2009 : 22:07:45
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Just fitted a "1 /2 /Both Switch"
Still have power when in the off position !!!!! Although the 1 /2 works fine .
Suspect the switch as it doesnt seem to click nicely in the Off position.
I knew I should have taken that switch off Flinty at the St Ives meet !!! Unfortunately he was rather engaged over most of the afternoon in a deep conversation with a Certain John Smith
Adi |
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raymo
United Kingdom
322 Posts |
Posted - 25 Aug 2018 : 00:25:18
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quote:
Originally posted by Fred
quote:
Is it safe to switch from "one" to "two" or "both" when the engine is running
No, you could damage the alternator. Some of the more expensive switches are specified as 'alternator field disconnect' while switching and only these will be completely safe.
After using one for years I've recently come round to thinking that these switches are a waste of money, unnecessarily complicate the system and probably lead to some voltage drop anyway. You will inevitably forget to switch over just when it is most crucial. Spend your money on more battery capacity, put them all in parallel permanently and be sensible with power use. Whatever you do, you will be limited by the charging capacity available. Usually not a problem with an inboard but always a limiting factor with an outboard.
And diodes? You'll probably lose best part of a volt through the diode. When the batteries are low anyway that could easily make the difference between turning the starter and not.
raymo. |
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raymo
United Kingdom
322 Posts |
Posted - 25 Aug 2018 : 00:37:01
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Oh wow!have no idea how I did that,was revising stuff to get me re acquainted, though,now we are here, is Freds view correct? and is the simplest way to achieve this just to leave switch on "both"incidentally batteries now replaced by 3x 110ah numax,so obviously hefty so would need to re-learn the best way to get the best out of them.(say re-learn as have had neuro problems and some stuff needs re remembering,if that makes sense)
raymo. |
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cliveshep
Thailand
1324 Posts |
Posted - 25 Aug 2018 : 02:25:31
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My Ocean had 3 x 120 AH truck batteries and there were two engine driven alternators feeding them. One was starting only, two were auxiliary power from memory. Also from memory - the isolator switch was one/two/none thus satisfying BSS.
Finally living the dream!
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Topic |
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needed,a morons guide to battery switches
