Manually jump starting 24v system?

[MV Mystery]

I have nearly 4 year old Die Hard batteries - 2 banks at 24v. This past week I tried to start my engines (8v92ti’s) and unusually my Charles battery charger was off at the time. Neither engine would turn over. Once I put charger on, after a minute or two, both engines fired up without the slightest hesitation.
Haven’t yet checked cells with my hydrometer but I suspect these batteries are on their last legs or is it the norm to start with the charger on?

Another issue I uncovered is- for the past 15 years I’ve never needed to use the parallel switch, and with this issue- it did not work. No click sound- nothing upon further checking. I will have to investigate this further.

This had me thinking- in an emergency, how would one manually jump start one bank with the other bank with the other in a 24v system with a pair of jumper cables?

 

[oscarvan]

Same as a 12V system, plus to plus minus to minus. Trick is to be in the right spots which depends on how it's wired.

 

[MV Mystery]

My battery banks sit between the engines - so they are literally two feet apart.

 

[racclarkson@gmail.com]

You know, I’d have to suggest you be very careful with arcing. Maybe connect ground to block or at least ensure good ventilation. If you haven’t experienced a battery explosion you should try to keep the streak going.

 

[SKYCHENEY]

Use the parallel switch

 

[bigbill]

Use the parallel switch

he said it doesn't work.......fix the parallel switch

 

[madhatter1]

Repair the parallel switch. Then use it every now and then to exercise it. You don't want to use it all the time because when a battery starts going bad it will be much worse when you notice it and both sides will be going out.

I start Every few times with the parallel. Watch the voltage gauges. Then the times without using also watch the gauges. When you see one bank drop more than normal this means the end is coming but you still have some time. By the time you need parallel to start engine with bad bank you don't have many starts left. But like everything else on a boat no big deal (other than boat bucks) if you know what is going on and deal with it accordingly.

Bet your parallel switch comes back to life with tapping while engaged. Hatteras used very good stuff.

 

[SKYCHENEY]

Another question: Do you know how to use the parallel switch? It has a toggle that you switch to the stbd or port. This is to select where the voltage comes from to energize the switch. So, if the stbd bank is dead, you toggle the switch to port. I have heard some who thought that you toggled it toward the engine you wanted to start which is opposite of what you would normally need to do.

 

[Fanfare]

As Sky said, move the parallel switch to the good bank, then hold the parallel button down continuously, and still holding down the button press the start button. Port engine now can start from the opposite side batteries.

 

[MV Mystery]

Another question: Do you know how to use the parallel switch? It has a toggle that you switch to the stbd or port. This is to select where the voltage comes from to energize the switch. So, if the stbd bank is dead, you toggle the switch to port. I have heard some who thought that you toggled it toward the engine you wanted to start which is opposite of what you would normally need to do.

Good question. I have no literature on it and I can’t recall any discussions with previous owner at the time. (15 years ago)

My setup has a “parallel “ press button next to each engine start button. I assumed that you press both together to start that engine.

 

[racclarkson@gmail.com]

Not all setups are like that. For example, both motors on Aslan crank on the starboard bank. The parallel switch ties the house bank into the cranking.

 

[SKYCHENEY]

Not all setups are like that. For example, both motors on Aslan crank on the starboard bank. The parallel switch ties the house bank into the cranking.

Right, some have been modified from the original setup.

 

[whoover]

Maybe the original posters switch does work properly, it was just very low voltage that was keeping it from combining the battery banks?

Walt Hoover

 

[questover]

I had same problem with the switch brought a new solenoid - still did not work. ended up being the fuse was bad. check fuse..

 

[MV Mystery]

This is my parallel switch. It’s has Marinetics Corp. On the housing. Does anyone have something similar?

 

[Captain Ralph]

You know, I’d have to suggest you be very careful with arcing. Maybe connect ground to block or at least ensure good ventilation. If you haven’t experienced a battery explosion you should try to keep the streak going.

Most marine diesel engine starters are insulated between the negative connect and the block. Block ground is not necessarily battery negative unless the negative stud on the starter is strapped to the block. You may fry a lighter wire or component if you try block to block.

Of course, sparks in the machinery room should always be avoided. Not just the engines fuel but the gas from the battery has an explosive personality also.
This is why a working & proper battery parallel solenoid is important.

 

[Captain Ralph]

This is my parallel switch. It’s has Marinetics Corp. On the housing. Does anyone have something similar?

That set-up looks like it can tie 3 different banks.
House and each main starting batts?

They should diffidently give a good click when used?