question

scotiad avatar image
scotiad asked

What size altenators are required to run the 24/3000/70 multiplus

Hello what size altenators are required to supply the inverter with enough power. We have 2 1000cca batteries.

powerassist
2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

4 Answers
paul-c-olin avatar image
paul-c-olin answered ·

Get the manual :

Manual-MultiPlus-3k-230V-16A-50A-(firmware-xxxx4xx)-EN-NL-FR-DE-ES-SE.pdf

Your model is mentioned but you need to pick the right input power (the figure after the 70).

Go to §5.5.1.5 Examples (on page 17 on my version).

The first 3 dip switches (8,7 and 6) let you restrict the input power, which helps you to protect from overloading your genset. With switches 4 and 3 you can control the battery load current.

As a matter of fact the genset you connect can be a big as you want, you could even connect the multiplus to the grid. The 8,7 and 6 switches do LIMIT the input to a max value, no force the genet to deliver a minimum. In my cas with a model with 16 as the last figure, I can limit the current to 5 Amps. Read the rest of the paragraph carefully and set ALL the switches in the position you want, because by pushing the UP or DOWN button you override ALL the factory settings concerned in the table. On a new device the are all set to OFF.

Good luck and hope your Multiplus will accept the genset current which is not always the case.

@ScotiaD

1 comment
2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

scotiad avatar image scotiad commented ·

When ever i decide to Use the inverter at 3000w and recharge from the alternator, the alternator should be a specific size in order to keep up with the demand of the inverter. What size(amps) should the alternator be.

0 Likes 0 ·
paul-c-olin avatar image
paul-c-olin answered ·

Look at the complete model number, either it is 24/3000/70-16 or 24/3000/70-50. The last figure indicates the max current the Multiplus can take, 16 Amp or 50 Amp. It will not swallow anything more.

The 3000 figure means you can draw 3000W at the AC output. Making abstraction from the power factor it would mean that -theoretically- 3000 ÷ 230 ÷ 0.95 (efficiency) = 13.7 Amps is used to to supply the AC outlet, leaving 2.3 Amps to charge the battery. Or 5000 ÷ 230 ÷ 0.95 = 22.9 Amps for the 5000 model, leaving 22.1 Amps to charge the battery.

The answer to your question remains rather simple : Get a generator that can produce 16 Amps ( 3680 Watt) or 50 Amps (11500 Watt). But don't rely on the figures painted on the machine, ask for the real ratings.

@ScotiaD

2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Justin Cook avatar image
Justin Cook answered ·

@ScotiaD, the answer depends on your load, not particularly the Multiplus. The Multiplus is taking 24v from your battery bank (for which the relevant measurement will be the total Ah, not the cca) and turning it into AC power, and your alternator will be recharging the battery bank. The alternator is not powering the Multiplus. How much power the Multiplus is drawing from your battery bank (and, therefore, how big of an alternator you need to recharge the batteries) is dependent entirely upon what you have plugged into the Multiplus, not the Multiplus itself. Therefore, to enable any of us to answer your question, please rephrase stating: 1. The total Ah of your battery bank; and 2. The expected draw of your total AC loads that the Multiplus is powering.

2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

dwmarine avatar image
dwmarine answered ·

The alternator should be a certain size for your battery bank. the battery manufacturer will have a spec for your model of batteries

Normally on a lead acid battery you need 10-15% of your batteries Amp/ Hour capacity as charge current, so 100 to 150 amps per 1000A/h battery to maintain battery condition.

If you just specifically want the answer to your question, 125 amps at 24 volts equals 3000 watts,

you need to allow for efficiency losses, alternator heat de-rating and target voltage which may be more than 24 volts.


2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Related Resources

Additional resources still need to be added for this topic