Q genny start battery connection to service batteries

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vas

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another quick one,

checking in the e/r I found two sorry looking cables connecting one of the service batteries to the smallish car size 12V starting battery of the gennie. It is a botch up job for sure.
So Q:

is it right to connect STRAIGHT no protection or anything one of the 4 service bank batteries to the gennie starter motor?
I mean I could discard the gennie starter motor battery altogether and wire the thick cables to one of the service batteries straight away, what's the point?

cheers

V.
 
virtuvas said:
another quick one,

checking in the e/r I found two sorry looking cables connecting one of the service batteries to the smallish car size 12V starting battery of the gennie. It is a botch up job for sure.
So Q:

is it right to connect STRAIGHT no protection or anything one of the 4 service bank batteries to the gennie starter motor?
I mean I could discard the gennie starter motor battery altogether and wire the thick cables to one of the service batteries straight away, what's the point?

cheers

V.
Click to expand...

Your service batteries will all be joined together in parallel, effectively giving you one giant 12v battery. Connecting the gennie start battery to one of them makes that part of the service bank.

I cannot see the point in having the gennie start battery if it's going to be connected to the service bank. I think i'd prefer a starter battery that was capable of starting the gennie. I'd connect that to either the service bank or the main engine start bank, via an isolator switch, for emergency gennie starting (in case it's start battery failed). You'd need to make sure the gennie start battery was connected to some form of charging device.

If you're happy for it to be wired to the service bank as it is, i'd remove the start battery and fit new cables.

A lot of the time, the battery cables are not protected by a fuse. Sometimes a circuit breaker might be fitted in the positive cable, close to the battery. But, in this case, you'd have to fit one at each end, as there is a battery at each end. I'd fit new cables and make sure they are securely routed so that the positive cable cannot chafe against anything negative and short.
 
Paul thanks for the reply.

One clarification, I'm running 24V, so the 2 12V batteries are joined in serial for the 24V of the starter motors for the two engines, the other 4 are in pairs serial and together parallel to get you the higher amperage 24V.
So now, ONE of the four service batteries is connected to the gennie.

I'm not sure if it's OK to run the gennie without it's own dedicated battery (but effectively that's what now happening since the lot are live...)

I'd be tempted to rip the two cables and just have the jumper leads near by (that's where they are anyway) in case the 12V car battery of the gennie fails.
IIRC the gennie itself should be charging it's own battery, no?

In which case I should be alright and have an emergency policy without depleting all of the service batteries if something happens in the gennie starter motor circuit while I'm away (I know it's highly unlikely, but don't see the point for the extra complication tbh)

cheers

V.
 
virtuvas said:
Paul thanks for the reply.

One clarification, I'm running 24V, so the 2 12V batteries are joined in serial for the 24V of the starter motors for the two engines, the other 4 are in pairs serial and together parallel to get you the higher amperage 24V.
So now, ONE of the four service batteries is connected to the gennie.

I'm not sure if it's OK to run the gennie without it's own dedicated battery (but effectively that's what now happening since the lot are live...)

I'd be tempted to rip the two cables and just have the jumper leads near by (that's where they are anyway) in case the 12V car battery of the gennie fails.
IIRC the gennie itself should be charging it's own battery, no?

In which case I should be alright and have an emergency policy without depleting all of the service batteries if something happens in the gennie starter motor circuit while I'm away (I know it's highly unlikely, but don't see the point for the extra complication tbh)

cheers

V.
Click to expand...

Ah, i see. If the gennie charges it's own battery, then there's no point at all in having it connected to the service bank. I'd take it off, personally. It's be nice to have it wired via an isolator switch for easy emergency starting, perhaps ?
 
PaulGooch said:
Ah, i see. If the gennie charges it's own battery, then there's no point at all in having it connected to the service bank. I'd take it off, personally. It's be nice to have it wired via an isolator switch for easy emergency starting, perhaps ?
Click to expand...

Is it wired this way so the mains/battery charger can charge the genie starter battery as well? Could you fit a VSR to get it to drop out of the circuit once charged.
 
wakeup said:
Is it wired this way so the mains/battery charger can charge the genie starter battery as well? Could you fit a VSR to get it to drop out of the circuit once charged.
Click to expand...

I did wonder if it was for mains purposes. I think rather than fit a VSR, i'd add a smart charger, if the current mains charger doesn't have an available 12v output.
 
how many genny battery's are there
just one or two ? (not completely clear from your post)

if two, are they in serie or parallel ?

I just asc, as in my boat the genny starters are on a separate 12V (x2) battery bank.
while the engines and the domestics are 24V
and I have a backup link switch between the 12V bank and the center point (12V) of the 24V engine bank

edit
after re reading your post, I believe you have the same,
you could place a isolating switch on these loose end cables, (just for backup reasons)
but make sure that the lead coming from the 24V bank carry's 12V = connected to the center point.
you could add a simple and cheap 230V/12V charger to keep the genny battery loaded,
I use that 12V bank / cirquit for Stereo and alarm, and the old VHF, and a few 12V sockets on deck.
 
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not so sure I'm less confused now tbh.

It seems that ppl think that the genny WONT charge its own starter battery? I never thought of that tbh...

Yes I only have one 12V car size battery for my 4-5KW Mase genny. Haven't manage to find the specs of the genny so don't know much, haven't even manage to find the actual model of the genny, have to remove all the crappy green insulation panels around it.

Yes, I'll replace the cables and fit an isolation switch keep it in the off position and only use it after long periods of no use to the genny.
Or rip the cables and use the jumper leads if needed.

Bart, there is a 24V->12V small box (100X150X40mm) next to the mains charger, got to trace cabling and figure out what's doing what. So will come back for that once I have more info. I'd also have thought that easiest thing to have 12V around would be to take from one of the service batteries but atm there's so much cabling around them in the e/r that I'm lost, slowly coming down there from the helm so will be a few more sessions on the boat before I understand it.

cheers

V.
 
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Careful here - when I installed my gennie the manual stated max starter battery size as 44ah. I didn't want the complication of a dedicated gennie battery and extra mains charger, so I connected it to my 220ah engine batteries.

It actually worked for about a year before the smoke came out and the 12v didn't. I'd fried the 12v rectifier box by overloading it by about 500%!!!

I erroneously assumed the rectifier box included some sort of current regulation, but it didn't. New box wasn't too much or complicated to fit, but bear in mind I'd also fried the 12v wiring on the gennie, which is a serious fire hazard.

CHECK to see if it charges it's own starter battery and what the load limit is before connecting it to a big battery bank.
 
Vas,

just to explain some principles,
here is a drawing of my setup, (apology's for the quality)

DCcircuitdiagram.jpg


from what you explain, I conclude you have more or less the same,
ofcause many variations or simplifications are possible,

It would surprice me if there is no alternator on your genny,
but even then, you would need a (cheap) 230V/12V charger, to keep the battery's topped up while the boat is moored.

I'm not sure if your 24V to 12V convertor can be used to charge the 12V battery
 
reviving a v.old thread I started in 2012...

OK, genny is a Mase, apparently around 8KW.
That is a Yanmar 2S diesel mated to a Mecc Alte generator.

Had a 100Ah sealed 12V battery (from a large building UPS) going spare, so fitted it in MiToS.
Two months later and after 6-7h or genny operation, battery was flat. Yes nothing charges it, but apparently there's some current drawn not only when cranking but whilst genny is running.

Anyway, searched a bit more, found two hi-fi speaker terminals (to get an idea of what I'm talking about) saying 12V next to the two schuko plugs on the generator body panel.
Also checked that there is no alternator on the Yanmar.

Questions:

  1. what are these plugs/terminals for? just output a secondary circuit to 12V for devices, or to charge the genny battery? If the latter, does it do conditioning, floating whatever or is it pumping loads of current to the battery all the time?
  2. do I get a CTEK (or equivalent) 3.6 or 3.8A charger plug it to the 220V circuit and get my battery charged when either genny is running or I'm hooked to shore power?
  3. do I install an alternator on the Yanmar (which begs the Q how the heck is the battery charged when genny is not running for sometime?

looks like option #2 looks more reasonable, whereas option #1 will be the cheaper (until it blows the battery...)

cheers

V.
 
Solution #2 looks to me the way to go.

We're on a similar set up , a 24V boat, with a genny with it's own dedicated 12V start battery, the genny in our case does charge the battery when it's running but I'm in the process of permanently plumbing a C-Tek charger onto the battery . It will charge the 12V battery whenever we are on a 240V supply whether that is shore or genny. That seems to have covered most bases from my perspective. The charger is connected down in engine room via an extension lead at the mo but will be properly wired in the 240V soon.
 
thanks Andrew,

will do a test on #1 and see what sort of current it's pumping out and being a cheapskate try to find a cheap #2 solution :D
My only concern, that I failed pointing in my previous message, is that I'll be installing 2X250W solar panels which will be feeding straight onto the service bank (@24V) so genny wont be getting any sort of regular top-up except when I'm running the watermaker or some other heavy device (not often)

cheers

V.
 
hm,

struggling to find a small charger either CTEK or even Victron that has no buttons to press and once 220V is available it starts doing it's thing. Being going through Victron manuals, all the small ones need user intervention to start charging EVERYTIME which is unacceptable for an installation like that!
You either have to choose current (6-12V) or type of battery, or type of charge you wish and they do bugger all unless you start pressing the Mode button on them!

Any ideas (preferably under 100euro!) most welcomed!

cheers

V.
 
The one I bought from our chandlery for Hollywood appears to do exactly what you're looking for, but my mistake, it's actually a Mastervolt, not a C-Tek, but it looks to be a nice little unit, has been working fine for me since September :
http://www.mastervolt.com/products/easycharge-portable/easycharge-portable-43a/
Showing in the UK as around 60 Euros. It comes with the short additional piece with the correct fittings to hard wire onto the battery terminals

Andy
 
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Vas, i have a Victron 12v charger that doesn't need a intervention on BA, i'll find out and let you know more info when i get on a computer...
 
Hi Vas,

I have a small MASE generator which although doesn't have an alternator does have a 10A 12V regulator for charging it's own battery.

It's the silver thing, middle right of the picture.

mase%20batt%20charger_zpszc01ngce.jpg


From the manual..

"The generator includes an electronic device to
automatically recharge the start-up battery, giving 10
A, at a voltage of 12 V, when fully charged."

Kevin.
 
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KevB said:
Hi Vas,

I have a small MASE generator which although doesn't have an alternator does have a 10A 12V regulator for charging it's own battery.

It's the silver thing, middle right of the picture.

mase%20batt%20charger_zpszc01ngce.jpg


From the manual..

"The generator includes an electronic device to
automatically recharge the start-up battery, giving 10
A, at a voltage of 12 V, when fully charged."

Kevin.
Click to expand...

Kevin,

mine is slightly older than yours, has dark green grp box in 3 or four pieces (fallen appart, scrapped it and will built a soundbox for it!) so maybe that's the case with mine. Got any online manuals to figure out how it works?
As I said the box with the voltometre and the two schuko plugs on top of the generator part (not engine!) does have connections for 12V, but that means external second set of wires going to the battery to charge it if that's the case.

Does yours need a second set of cables to the battery?
What does the regulator do, I thought it would mean having a secondary wiring on the generator that outputs 12V instead of 220V, is that what the regulator do, convert the 12V alternate to DC?
Mind haven't spotted a box like that on the gen body...

Even more confused and the fact that I don't know the model/year of my setup is not helping much. Not had much luck finding manuals online :(

cheers

V.
 
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