| T O P I C R E V I E W |
| raymo |
Posted - 03 Jul 2009 : 22:13:34
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. |
| 15 L A T E S T R E P L I E S (Newest First) |
| IanM |
Posted - 29 Aug 2018 : 06:54:36
Another vote for Voltage Sensitive Relays from me. It makes the batteries a no-brainer to charge regardless of the charging source (Alternator, solar, mains) |
| Sonny |
Posted - 28 Aug 2018 : 22:41:36
I've had a system on my boat for three years with no probs that consists of a starter at 60 amps and a leasure battery at 110amps both are on individual isolater switches and fuse panels but there is a voltage sensitive relay between the so that the starter charges to 13.4v then the relay switches to charge both battery's from the same alternator. I also have a solar panel at 85w that is permanently connected to the starter battery and when this is full the relay switches to charge the leasure battery. After three years on a mooring with no mains power both battery s are working fine and have never been off the boat for charging. All lighting is led we have a small flat screen tv and the boat is in the water winter and summer. |
| cliveshep |
Posted - 25 Aug 2018 : 02:25:31
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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| raymo |
Posted - 25 Aug 2018 : 00:37:01
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. |
| raymo |
Posted - 25 Aug 2018 : 00:25:18
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. |
| adi-n-chez |
Posted - 05 Jul 2009 : 22:07:45
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 |
| Fred |
Posted - 04 Jul 2009 : 22:02:04
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. |
| golligy |
Posted - 04 Jul 2009 : 21:09:39
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. |
| golligy |
Posted - 04 Jul 2009 : 21:06:06
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. |
| Fred |
Posted - 04 Jul 2009 : 17:12:49
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. |
| TheBoatMan |
Posted - 04 Jul 2009 : 16:49:55
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) |
| raymo |
Posted - 03 Jul 2009 : 23:51:26
off to swot up on diodes ! |
| adi-n-chez |
Posted - 03 Jul 2009 : 23:43:15
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 |
| raymo |
Posted - 03 Jul 2009 : 23:28:21
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. |
| raymo |
Posted - 03 Jul 2009 : 23:15:33
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. |
