(2) 6 volt golf carts as a starting battery

[DotDun]

Been starting with deep cycle for 10 years, no problems.

[DeborahLee]

Been using the same system also, has worked great. The starting battery is first to charge as it only takes a couple minutes after the engine starts. Then the combiner kicks in. As for 5 batteries in the box think outside the box especially if you have a Yanmar. I installed a new box ( a ready made one) close to the engine along with increasing the wire size from the starter switch and no more Yanmar starter problems. Starts first time every time.

[Stu Jackson]

The Blue Sea dual purpose switch has severe limitations in sailboat use, it is good for powerboats who start their engines multiple times during the day. A simple 1-2-B switch, and, if you like, a separate switch for the reserve bank, is all you need.

AGM Battery Issues and the Blue Seas Dual Circuit Switch (from Maine Sail) "DARN AGM Batteries"
Darn AGM Batteries - SailboatOwners.com

Alternator Regulator Wiring Diagrams Alternator Regulator Wiring Diagrams (all three)

How Alternators & Regulators Work PLUS External vs. Internal Reguators (by Maine Sail): Musings Regarding External Regulation - SailboatOwners.com

Basic Battery Wiring Diagrams This is a very good basic primer for boat system wiring: http://c34.org/bbs/index.php/topic,6604.0.html

This is another very good basic primer for boat system wiring: The 1-2-B Switch by Maine Sail (brings together a lot of what this subject is all about)
1/BOTH/2/OFF Switches Thoughts & Musings - SailboatOwners.com

[colemj]

Do you mean the Blue Sea ACR? If so, I cannot find any limitation, let alone "severe" of using a combiner. We have had them for 15yrs on a boat with a large house bank, two engines with starting batteries, a generator and complicated electronics and electrical system. Just install and walk away - it works perfectly, keeping all batteries well charged and isolating them when being discharged.

So, without making me read through 5 treatise trying to suss out your particular points, can you simply summarize why an ACR has severe limitations in a few sentences?

Mark

[Pete the Cat]

Been using 6v batteries for starting for 21 years, no problem ever. You do not need a starting battery. Retread Nigel Calder again.

Ray

[hellosailor]

A very small deep cycle battery might have a problem turning over a larger starter (i.e. big diesel engine). That's why there are numbers on all these things, as others said, as long as the battery is rated to provide more amps than the starter draws, everything is happy.

[Jsol]

Originally Posted by colemj

Do you mean the Blue Sea ACR? If so, I cannot find any limitation, let alone "severe" of using a combiner. We have had them for 15yrs on a boat with a large house bank, two engines with starting batteries, a generator and complicated electronics and electrical system. Just install and walk away - it works perfectly, keeping all batteries well charged and isolating them when being discharged.

So, without making me read through 5 treatise trying to suss out your particular points, can you simply summarize why an ACR has severe limitations in a few sentences?

Mark

I think Stu is referring to the Blue Seas 'add a battery' switch/ACR where you only have 'house' and 'combine' and the potential problem of combining a large bank that has been drawn down to a small topped up battery whereby the smaller battery quickly gets drawn down by the large depleted bank as opposed to a stand alone ACR/switch...

[Maine Sail]

Originally Posted by Jsol

I think Stu is referring to the Blue Seas 'add a battery' switch/ACR where you only have 'house' and 'combine' and the potential problem of combining a large bank that has been drawn down to a small topped up battery whereby the smaller battery quickly gets drawn down by the large depleted bank as opposed to a stand alone ACR/switch...

If you have a catastrophic fault in one bank your only option with the DCP switch is to combine a bad bank with a good one. I would always rather isolate the bad bank than parallel it with a good one.....

It is a very simple switch but not perfect in all areas....

[capngeo]

I use 6Vin series for the house bank and a small 12v (Group24) cranking battery for the main and genny (one battery starts both engines) The Propulsion engine alternator charges the starting battery only... but I can switch it to the house by an AB switch. The genny charges the house bank via the batt charger

[hellosailor]

"I think Stu is referring to the Blue Seas 'add a battery' switch/ACR where you only have 'house' and 'combine' and the potential problem of combining a large bank that has been drawn down to a small topped up battery whereby the smaller battery quickly gets drawn down by the large depleted bank as opposed to a stand alone ACR/switch... "
But if the ACR works like most combiners, it cuts in (combines) at alternator voltage, (~13.8VDC) and then drops out (breaks the connection) once the alternator voltage ends. So that there is zero danger of a large house bank sucking down a small SLI battery, because as soon as it sucks down to the magic number--the combiner splits them up again, leaving the SLI fully charged.
No?

[Maine Sail]

Originally Posted by hellosailor

"I think Stu is referring to the Blue Seas 'add a battery' switch/ACR where you only have 'house' and 'combine' and the potential problem of combining a large bank that has been drawn down to a small topped up battery whereby the smaller battery quickly gets drawn down by the large depleted bank as opposed to a stand alone ACR/switch... "
But if the ACR works like most combiners, it cuts in (combines) at alternator voltage, (~13.8VDC) and then drops out (breaks the connection) once the alternator voltage ends. So that there is zero danger of a large house bank sucking down a small SLI battery, because as soon as it sucks down to the magic number--the combiner splits them up again, leaving the SLI fully charged.
No?

It is not about the ACR portion of the product it is about the battery switch itself. ON/OFF/COMBINE. In the event of a failed bank there is no way to isolate the bad bank and switch to the good one. The only option is COMBINE or OFF.....

[hellosailor]

"the battery switch itself. ON/OFF/COMBINE. "
A switch that is 1-off-both ?? That's odd. Sounds like something that would be made by either Lucas or the French. It must have made sense to someone. Sometimes I think a simple SPST switch for each battery would be the simplest way to go.

[chouliha]

We have been using 6v deep cycle batteries for 27 years and never had a problem using them for engine starting. In fact we never had a dedicated engine start battery but use the house bank to start the engine.

Good luck with your choice

Chuck
Jacaranda
Ecuador

[scoobert]

with a boat as small as what you or i have, you can get away with just a simple 12 volt 750CCA 12 volt battery. put a trickle charger on it if you want.

[asahi]

I read this thread and decided to use 2 golf cart batteries as my house bank as well as for starting. My 15hp Yanmar only requires 115 CCA I believe, so the batteries were able to start it up with no prob.

I don't have a backup battery yet, but am thinking of getting a portable jump charger - the kind that are small enough to fit in a glove box - for this purpose.