Volvo MD30 Starter: real current use

[CaptainRivet]

HI all,


could anyone please tell me how much ampere the Volvo penta MD 30 starter uses in reality?


Its rated at 3kw so 3000W with 12V so 250A but how much is it in reality?
Boat is 3000km away so I cannot measure it myself.
Thank you

[tkeithlu]

Maybe, if there is a Volvo person available, but current draw is dependent on a bunch of variables, such as temperature, oil viscosity, size wire, compression, and you name it.

What problem are you trying to solve? There may be other ways to assist you.

[CaptainRivet]

Originally Posted by tkeithlu

Maybe, if there is a Volvo person available, but current draw is dependent on a bunch of variables, such as temperature, oil viscosity, size wire, compression, and you name it.

What problem are you trying to solve? There may be other ways to assist you.

Building a LTO battery as starter battery and make sure I size it correctly.
Well it can do 10C and in emergency up to 15C discharge, so a 40AH one with 10C so 400A/600A emergency should do it. But wanna make sure

[john61ct]

Note that the average amps over a sub-second surge will greatly depend on the sampling frequency and quality of the ammeter.

What is called 250A over say 5sec could easily be 800A in a millisecond context.

So the question needs asking

Why do you want to know?

What decisions are that data point going to influence?

[john61ct]

Originally Posted by CaptainRivet

Building a LTO battery as starter battery and make sure I size it correctly.
Well it can do 10C and in emergency up to 15C discharge, so a 40AH one with 10C so 400A/600A emergency should do it. But wanna make sure

Aha.

Wow, why LTO? Heading for the Arctic?

Related question, why not just use lead?

Toshiba's?

Link to source?

I'd think 40Ah is enough, but might be less stressful to go a bit higher.

But then even if you're cutting longevity in half you'll still get 5000+ cycles 8-)

Fancy stuff. . .

[CaptainRivet]

Originally Posted by john61ct

Aha.

Wow, why LTO? Heading for the Arctic?

Related question, why not just use lead?

Toshiba's?

Link to source?

I'd think 40Ah is enough, but might be less stressful to go a bit higher.

But then even if you're cutting longevity in half you'll still get 5000+ cycles 8-)

Fancy stuff. . .

preping my boat for a min. 5 years world curcumnavigation, barefoot root and no antartica.
why no lead acid, short I hate them and they always break when you really need them. outdated technology while you depend more and more on electrics on your boat.


using 6 Yinlong which cost me 250$, no BMS needed.

https://de.aliexpress.com/item/40002...chweb201603_53


connecting them with M12 thread sleeve
https://www.workerswelt.de/distanzmu...en-sechseckig/


stick it in a PVC pipe and done with it. Mount it, put a cell voltage monitor with alarm on it and forget about it.

so for 300$ I have a 40AH starter battery I can always rely on. But then the green hell's starter will break....well thats boat life and I will have 2 spares with me.

Having 1 cell extra, charged up and vaccum packed in case one cell dies. Self discharge minimal, like this 5 years storage minimum.


Lets see how it performs when I test it.
plan is 12V with 4x400 or 700A Winston Lifepo4 cell (house+bowtruster) and 40AH LTO starter


But thinking about alternative by making a 280 or 320A 14V LTO house bank with them and toss all other batteries on board => starter, bowtruster and AGM housebank.

Going full electric galley, washing maschine and 240V water maker too.

[CaptainRivet]

why I am asking about the starters current is that they acutally are 30-32AH cells and rated 340A which will still fit with enough headroom.
Just asking because a friends kubato engine starter is rated 3kw too but it actually pulls more like a 4,5kw one with around 350-400A.

[john61ct]

Thanks much. Have you got reliable feedback on Yinlong being known as good long term?

I'd consider moving the bowthruster to the Starter bank, maybe give you an excuse to go a bit bigger.

I like the idea of keeping the transient big-amp load devices separate from sensitive electronics if it isn't too much trouble.

Do **not** go to just one bank, keep at least one as Reserve for limp-home mode just in case the fancy stuff fails on you. Ideally lead from that POV but not necessarily AGM.

Starter could switch from one to the other, same with other engine related and essential safety / nav / comms circuits,

[john61ct]

Originally Posted by CaptainRivet

rated 3kw too but it actually pulls more like a 4,5kw one with around 350-400A.

No one can answer the actual IRL question, transient high-amp loads are very different from normal ones, a lot less predictable.

IRL actual testing to see how much voltage sags, is really the only way, also check for Ah used per 5-sec of cranking.

Be conservative, maybe performance drops after the first few years, and

when you have engine issues you may be cranking the equivalent of 50x what you use when everything's tuned up.

______
I know unwelcome, but gotta say it

For less money a pair of 225Ah GCs is easily replaced even in the most primitive locations, tried and true, less likely to give any surprises.

[CaptainRivet]

Originally Posted by john61ct

Thanks much. Have you got reliable feedback on Yinlong being known as good long term?

I'd consider moving the bowthruster to the Starter bank, maybe give you an excuse to go a bit bigger.

I like the idea of keeping the transient big-amp load devices separate from sensitive electronics if it isn't too much trouble.

Do **not** go to just one bank, keep at least one as Reserve for limp-home mode just in case the fancy stuff fails on you. Ideally lead from that POV but not necessarily AGM.

Starter could switch from one to the other, same with other engine related and essential safety / nav / comms circuits,

yes a friends use them since 4 years in his car-hifi demo vehicle and they get seriously stressed. 80AH, in reality 60-70AH battery driving 6kw sub amps, other carhifi gear plus the whole car with a fat V8. Still have the "rated" capacity when he got them.


yes was thinking about the same config as my friends with a 60AH/70AH and bowtruster+starter on it too but then

a) the price point for it is not so sexy any more
b) I cannot do the simple and cheap pipe style anymore...bus bars and case adds another 200 bucks to a) which results in 800$ total done right.


idea about bowtruster on Lifepo house is I use it in 98% in the habour and then I have shore power to recharge so I can use it off the oversized house bank capacity for liveaboard.
Sure if I would go 320A LTO I keep 40AH/6 cells starter seperatly but can always join it to the house bank if needed. Thats the big plus if everything is the same...also if I need 24V, just configure the cells differently.



I am friend of backups, 2 water maker (one 12V with 6l/h and 4A use, manual operation possible plus 100l/h 240V one), Ketch=2 Masts with 4 sails and all manual whinches, 3 Chartplotter plus 3 Ipads+1 Garmin handheld, 2 inverters Victron....but yes a lot depends on the batteries so do it right here with best I can get. And as long as I have my workshop and very good supply location...remote it gets hell of expensive and time consuming


Well if it LTO breaks I can always get the 225AH lead in remote places but > 8000 lifecycles should prevent me from exactly this. More likely the starter or the raw water pumps of the green hell will die...

[Niall leslie]

For what it is worth.......
Good comments all.
It is very difficult to get LRA and operating A. draw for starters from the manufacturers. I suggest that you get someone to measure both on your boat with a good quality DC clamp on Amprobe.
For starter batteries CCA is what counts and I suggest sizing whatever battery that you decide upon to be minimum 5 times in CCA the operating starter draw in Amps. while making allowance for any tropical fill needed etc.
Cheers,
Niall.

[CaptainRivet]

Originally Posted by john61ct

______
I know unwelcome, but gotta say it

For less money a pair of 225Ah GCs is easily replaced even in the most primitive locations, tried and true, less likely to give any surprises.

banned


well I still have 2x140AH AGMs as starter/bowtruster from 2017 on board from previous owner...won't toss them and use for bowtruster but will try for 1-2 month with the 40AH LTO for engine and see.


exactly what I meant crank it for 5sek, measure current and AH.

[john61ct]

The peak transient current you "measure" is completely dependent on the instrument. Most ammeters won't see at enough resolution, need a $300 Fluke, or really an oscilloscope for accuracy.

And in fact even with a very precise current number, no one is going to know

how much voltage sag a bank composed of **those** cells will exhibit, or

what the wear & tear factor will be of such a transient C-rate

without IRL testing.

You being a pioneer, you get the arrows 8-)

[CaptainRivet]

Originally Posted by Niall leslie

For what it is worth.......
Good comments all.
It is very difficult to get LRA and operating A. draw for starters from the manufacturers. I suggest that you get someone to measure both on your boat with a good quality DC clamp on Amprobe.
For starter batteries CCA is what counts and I suggest sizing whatever battery that you decide upon to be minimum 5 times in CCA the operating starter draw in Amps. while making allowance for any tropical fill needed etc.
Cheers,
Niall.

well 5 times CCA you maybe need on a LRA (which is a 0.2 till 0.5C discharge battery with 20%-40%DOD) but an LTO with 10C permanent discharge till its empty/15C shortterm (not peak!) and DOD 80-100% I would and will calculate differently with 6-7C.
Different technology needs different calculations. You can only use 45AH of a 225AH lead acid but 32AH till even 40AH of a LTO 40AH. Starter battery now is a 140AH AGM and this 32/40AH LTO I plan can deliver double the power under any operating temp.
Absloute main reason to get a LTO battery is that its not permantly damaged unuseable if you discharge it completly to 0V as any other technology like lead or LiFePo.



In this case 1C is 40A and 6C=240A/7C=280A permanent current which exactly falls within spec of 250A max for a 3kw starter. Starters are made for shortterm use but not permanently so the 3kw is max peak if speced correctly.


Yes I would love to measure mine but cannot. So if someelse with the same engine has some measures thats best I can get and shouldn't be too far off either. A 3kw starter shouldn't be able to pull 400A in any circumstances (ok for some millisecs but the CTO will deliver even this peak with ease) unless its massivly underrated.

From my experience with engines that 3kw starter on a 62hp Volvo MD30 is/should be pulling around 150A when in moderate temps and only 200-230A when in below 0 Degree temps. And longer cranking with 250A will burn the coils of a 3kw starter if correctly rated.

[Boatyarddog]

Originally Posted by CaptainRivet

HI all,


could anyone please tell me how much ampere the Volvo penta MD 30 starter uses in reality?


Its rated at 3kw so 3000W with 12V so 250A but how much is it in reality?
Boat is 3000km away so I cannot measure it myself.
Thank you

Sure you can.
Get one of these.Or borrow one.
Clamp it on you'll get real time actual current use of what it is your measuring.
I'd go for a Fluke 323, more functions.
But, here's Harbor Freight
https://www.harborfreight.com/digita...SABEgKPIvD_BwE.
Cheers,
SV Cloud Duster