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Discussion Starter · #1 ·
I am working on a fleet build that requires about 600W of power on a 110V AC circuit. I can use that second battery circuit and a Gel Cell battery but I am not sure what the limitations are on that circuit to charge the battery. Any experience out there with a heavy draw on that circuit?
 

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I'm just guessing here but 600W is 50A at 12V say 60A with inverter losses. In 1 hour that would be 60Ah from the 95Ah battery without charging. 60A would need 6awg cable but it looks like the cable to the aux battery is at least that ( https://www.metrisforum.com/threads/auxiliary-battery-package.2146/#lg=thread-2146&slide=1 ) (2 or 4?). If the van is running, the 190A alternator should be able to supply that easily.
On the other hand, there is a 50A fuse mounted on the auxiliary battery clamp... if that's limiting the charging rate, it will be close.
Better see if anyone else has a more informed idea.
 

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If I understand your question correctly, it's 40 amp per Metris body and equipment guide:

"If the vehicle is already equipped with an additional
battery, no further additional batteries may be
connected in parallel without a charging current
limiter. This can be realized through supplementary
electronics. A maximum charging current for both
additional batteries of 40 A must be ensured by the
upfitter. If this is not the case, the basic vehicle may
be damaged."
 

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Looks like you can have a heavy draw on the auxiliary battery but not sustained indefinitely at more than 40A expecting the charging system to maintain it. If your 600W requirement is intermittent, e.g. a 50% duty cycle, 40A would probably do. (If it's sunny, you can add solar.)
 

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Discussion Starter · #5 ·
I'm just guessing here but 600W is 50A at 12V say 60A with inverter losses. In 1 hour that would be 60Ah from the 95Ah battery without charging. 60A would need 6awg cable but it looks like the cable to the aux battery is at least that ( https://www.metrisforum.com/threads/auxiliary-battery-package.2146/#lg=thread-2146&slide=1 ) (2 or 4?). If the van is running, the 190A alternator should be able to supply that easily.
On the other hand, there is a 50A fuse mounted on the auxiliary battery clamp... if that's limiting the charging rate, it will be close.
Better see if anyone else has a more informed idea.
Thanks for the input!

MK
 

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Discussion Starter · #6 ·
Looks like you can have a heavy draw on the auxiliary battery but not sustained indefinitely at more than 40A expecting the charging system to maintain it. If your 600W requirement is intermittent, e.g. a 50% duty cycle, 40A would probably do. (If it's sunny, you can add solar.)
I agree after some additional research - i will keep it under 35 amps
 

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How long are you going to need that 600w draw? On location with production lights we pull 600w continuous for 2.5 hours from 210 or 315 ah aux batts. On the way back to the office the Sterling DC-DC charger is in the 40 amp range and I've seen it hit 53 amps on the Victron battery monitor.
 
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