Emergency power station

My new to me Carver 350 Voyager with twin Volvo TAMD41B's has a somewhat strange electrical system that I am struggling to understand.
There is one 660 amp house bank(6-6 volt in series/parallel) and an isolated generator battery. The alternators are the standard 50 Amp Volvo, with internal regulators. They pass through an isolator that has three outputs.
I am concerned that one day I may not be able to start the engines through an error on my part! (I am not as smart as I once was.)
I don't really want to engage in a major rewiring project to have each engine with its own starter battery and I was wondering if the following would work:

I bought an Emergency Power Station that claims to have 500 amp + 1000 Amp peak jump starter that I'm thinking that I can use if the unthinkable happens. To at least start the generator, or in a push start one or both of the main engines. The generator is a NL 5 KW feeding a Xantrex 2000watt/100 amp inverter/charger.

My question is: Does anyone here have first hand experience with these things? It is marketed under Cat's name and seems to have some other nifty attributes like a compressor, USB port, 200W AC. It is, however, made in China. It needs to be charged up every 30 days, which should be no problem. Not sure how long it takes to recharge, as I have not opened the box yet, in case of return.

Thank you for all thoughts and inputs.

Ian Munro
Seattle
Carver 350 Voyager

I keep a "jump box" handy, always. In my truck, on the boat, it goes with me just like my little "tool box" that has just the most basic of tools and things. BoyScout.

Depending on your diligence with charging and maintaining, It could become a paperweight...also the cheaper ones tend to fail sooner than later. I say this because if the day comes that you really need it, it needs to work.

If gen has a standalone batt, and main bank starts the main engines, if you flatten the main bank the gen should still have a good batt. Just start it up and run the charger for a while to charge main bank.

"If gen has a standalone batt, and main bank starts the main engines, if you flatten the main bank the gen should still have a good batt. Just start it up and run the charger for a while to charge main bank."

Yes, I understand that. I was thinking of a dire circumstance where I forgot to switch off the gen batt. As I understand the system it would be possible to flatten all the batteries. The boat is 20 odd years old and has been subject to quite a few mods and additions and it is so cramped it is hard to follow what goes where. I plan to run the generator under way as the engine charging system is a little light. (Alts 50 amp each, and less when hot)

My generator battery is independent of everything except the generator. Only the generator charges it and it only starts the generator. It is not connected to any switch so cannot be drawn down by "misswitching". So outside of some other fault with the generator mechanics or fuel system the generator should be able to start and charge main engine start battery.

I agree with Steve. Isolate your generator battery from everything but the generator. This is simple to do at the battery itself. Buy the EPS if it makes you feel better but as long as you start and run the generator, at least monthly, I don't see the need.

I blessed my dedicated generator battery with a solar panel as well. It is our backup, the IG system does not provide a dedicated main engines battery either. On one occasion early in my ownership I needed it, and it worked.

Years ago I carried a jump start battery/kit. Now I have a single 12 volt battery separate from the house bank. This battery is under the helm and powers only the SSB and an emergency VHF radio. The battery has its own small charger which charges whenever the generator is on.

Once a year I have pulled this battery out of the boat to go and jump start some other boat that has let its batteries go flat. So far haven't needed it myself.

I ditched the genset battery and used the extra space for two more 6 volt batts. House bank is now 940 amp-hrs. The engines have dedicated 4Ds(which is over kill). The two 4Ds are kept separated and idle for only engine and the almost never genset start. Switch lineups can tie the banks if required. With three battery banks I just don't see the need for a fourth.

ianonhercules said:

Yes, I understand that. I was thinking of a dire circumstance where I forgot to switch off the gen batt. As I understand the system it would be possible to flatten all the batteries.

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There seems to be a disconnect here (no pun intended). If your gen start battery is dedicated to starting the gen, then there should be no need to switch it off. Do you know of something that drains the battery down if you don't shut it off? And is one of the isolator outputs connected to the gen battery? You said it has 3 outputs, so I'm guessing one for the main bank, one for the gen, and one unused? And I think all the NL generators have their own alternators to charge their start battery, but that's worth confirming.

As others have suggested, if your system is set up correctly you should already have a good level of redundancy; if main batteries go flat, start generator and recharge. If your generator battery goes flat, start main engine and recharge via isolator. It would be a double fault for both batteries to go flat, which you could certainly protect against, but I think in general people are just try to cover single faults.

If you don't trust switching to allow X-connecting you might also consider x-connecting w/ a solenoid and momentary switch... commonly done on motorhomes to provide emergency batt'y flexibility... provides the convenience w/o the possibility of mis-managing switches.

Another KISS alternative - carry a set of jumper cables instead of the emergency batt'y?

Solar Booster Pac brand

I have used the "Solar" Booster Pack brand jump battery for years. I keep one in the security office to jump cars when people leave their lights on. I have only had to purchas two units in 15 years and the unit is used several times a month. I have one at home that is about 8 years old and still serviceable. I originally bought it as a power supply for a small rib for fish finder and lighting. I made the mistake and bought a cheaper one once. Lasted about 6 months. The Booster Pack brand is around $100.00 and worth every penny.

twistedtree said:

There seems to be a disconnect here (no pun intended). If your gen start battery is dedicated to starting the gen, then there should be no need to switch it off. Do you know of something that drains the battery down if you don't shut it off? And is one of the isolator outputs connected to the gen battery? You said it has 3 outputs, so I'm guessing one for the main bank, one for the gen, and one unused? And I think all the NL generators have their own alternators to charge their start battery, but that's worth confirming.

As others have suggested, if your system is set up correctly you should already have a good level of redundancy; if main batteries go flat, start generator and recharge. If your generator battery goes flat, start main engine and recharge via isolator. It would be a double fault for both batteries to go flat, which you could certainly protect against, but I think in general people are just try to cover single faults.

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I think that is the way it is set up. One of the outputs from the isolater is taped off. One in center is putting out 14.35 volts and is going to main bank; the other is 13.85 volts which I suspect is going to the generator. There is a rotary switch that is an on/off that turns off the main bank (The PO called it a secret switch) and also a key switch] on the gen battery.

I thank you all for your insights . You have given me plenty to think about. I may have to get some professional help to sort out the wiring but for the moment, at least, I will return the jump starter. It is heavy and bulky and would be hard to stow.

Ian Munro
350 Carver Voyager
Seattle