Another battery bank thread

[oceanjake]

I read on an old thread about warm weather boats using golf cart batteries. Someone made a comment about melting the posts out trying to draw enough amps to crank. My port bank is golf cart batteries and they start the engine fine although I did have a post melt. Replaced the one battery for $130 and all seems good. I replaced the starboard side with another brand of golf carts and it worked for a week or so although slower cranking. Now they won’t even turn the engine. I’m trying to decide if I will replace with better quality golf cart batteries like on the port side, or if I will go with pure starting batteries. Does anyone know which side is the house bank on a 60SF typically? Also, are most of you using 8v195’s or 819’s? Best price on these?Thanks for the input.

[ian w]

I have had no problems starting 8 71. engines with golf cart batteries. I suspect a bad connection.
Golf cart batteries will take a cart and 2people 8 miles !!! That comment may or may not be relevant but they are putting out a lot of power

[wpc691]

I start my port side with 3 Grp 31 Workaholics, and the stbd side with 6 GC2’s. I’ve never had any problem starting the GC2 side. However, the deep draw power of a GC2 means little when starting. Instant starting power depends on low internal battery resistance and high plate surface area, almost the opposite of a GC2. My opinion on successful starting with GC2’s is you need several batteries (to get as much plate surface area as possible), in good condition, correctly wired, and with scrupulously clean, tight connections with ordnance clamps if needed for multiple cables (NO molded studs, failure waiting to happen).Just curious, why start with a golf cart battery bank if it’s not also being used as a house or inverter bank?

[Toolsntoys]

This thread is perfect timing as I have questions also about using golf cart batteries. I’m in the process of installing a 12 volt back to run most everything on my boat the two 32 volts banks would probably be for engines and the windless. I was hoping to use smaller size batteries so I can have space for a really large 12v house bank and another 12v bank for the generator

[Scarlett]

Everyone considering replacing starting batteries should look into an ultra capacitor. They are about the size of a group 31 battery, and will easily start 2 large Diesel engines and a generator. They have an internal charger that can recharge the capacitor in about 10 minutes at 10 volts. I had one in my last boat, took out 2 8D’s and a small gen start battery and gained a ton of space. Now the bad news, only 12 volts or 24 volts no 32 volts and cost about $1000.00 but you will probably never have to replace it. I got mine from a friend who worked for Maxwell industries, one of the companies that make them. I got a damaged case one for nothing. I think this is the kind of tech that will have huge price reductions as production increases. There major market is European busses that have to shut down the engines every time they stop and the capacitors fire up the engines almost instantly. The output voltage is 16 volts so a 12 volt starter goes really fast. John

[Boatsb]

Asking again will not change the facts. I know so many believe it will and keep asking.

The 819 is larger and heavier duty than the the 8v195.

The golf cart batteries were not designed to start engines.

Cable size and length matters.

If something works for you great. Have at it but please don't sell the idea as the right way to do things as when someone is in a situation where failure is not an option and the hack fails someone could get hurt.

[Pascal]

If you put new batteries and after a week you couldn't crank, have you checked th charger and voltage? Is the starter itself tired?

I used gold cart batteries for about 9 or 10 years and they worked fine. Each set lasted about 4 to 5 years They key is to have good solid connections. 30 year old cables and connectors are past their primes especially considering the long cable runs on many boats

That said the correct way to set up the boat is to have a starting battery / bank for each engine and generator plus a battery bank (deep cycles or golf cart) for the house bank. Sharing starting and crank is a compromise adequate on a smaller boat but not a boat like hours with plenty of room

That's what I m doing on mine. A single 8 D for each engine close to the starter with a manual parallel switch. A G31 for the genny and 8 golf cart for the 24v house bank. It s a little more complex with 32v systems but worth the piece of mind and redundancy

I m also relocating the batt switches out side the ER for safety.

[krush]

Everyone considering replacing starting batteries should look into an ultra capacitor. They are about the size of a group 31 battery, and will easily start 2 large Diesel engines and a generator. They have an internal charger that can recharge the capacitor in about 10 minutes at 10 volts. I had one in my last boat, took out 2 8D’s and a small gen start battery and gained a ton of space.

Thanks for posting this. I figured these devices were out there, but I didn't know they were so mainstream. I'm going to look into it. Have one for each engine, then a huge house/inverter bank.

[MagnaBill]

Thanks for posting this. I figured these devices were out there, but I didn't know they were so mainstream. I'm going to look into it. Have one for each engine, then a huge house/inverter bank.

Be great to know what you find out Krush. Can the house then back up the capacitors?

[krush]

Be great to know what you find out Krush. Can the house then back up the capacitors?

This is kinda cool. 15volts to the starter from 10v batteries:

Yes, the ESM will continue to take a charge and remain @~15V until the batteries are down to ~9V. At that time the ESM will isolate itself and no longer take a charge; the Status LED will display a flashing green-solid red indicating a battery under-voltage condition. Once the batteries are above 9V the ESM will automatically reset.

Yes, the starter + sees at least 15V, and because they are ultra-capacitors (not Lead-acid) the voltage will increase as the temp drops. So at temps below 0F you will see the voltage increase up to ~16V.

We have thousands of units currently in service under a broad spectrum of applications throughout the North America and see very low failure rates. Most of the failures are from mis-installation or someone trying to charge the unit by putting the charger leads to the Starter + post and Ground (this will damage the logic inside).

More info here: https://www.thetruckersreport.com/tr...posts/3965410/