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Hi All,

I think this is a fairly basic question but I have not been able to find it. My desire is to charge off of 110v; but with either a standard 15 amp wall circuit or from a stronger 30 amp circuit.

Can the amperage draw be switched at the charger and/or the BMS? If neither, would I need two chargers and one BMS or two chargers and two BMS?

Thank you!
 

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You need a charger rated for that amps level, with good overcurrent protection.

Or higher amps, with derating capabilities.

High end power supplies you can dial it in
 

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Hi All,

I think this is a fairly basic question but I have not been able to find it. My desire is to charge off of 110v; but with either a standard 15 amp wall circuit or from a stronger 30 amp circuit.

Can the amperage draw be switched at the charger and/or the BMS? If neither, would I need two chargers and one BMS or two chargers and two BMS?

Thank you!
It is not so simple. The amperage draw can be set at the charger. But there is a limit to what it can be set, and it may not be possible to double the current draw. The charger has a wattage rating, and also the BMS has a rating, and also the battery pack has a rating. The most you can draw is the minimum of the above three wattage ratings.

For example, let's say the pack can be charged at 3 kW and the charger rating is 3 kW, but the BMS can only handle 2.2 kW. Then if you are charging at 15A, that would be 1.65 kW. You can increase that to 2.2 kW or 20A supply draw, but you should not exceed 20A, even though your power circuit can deliver 30A.

If the battery pack and the BMS can handle 3 kW, and your charger is 1.5 kW, then possibly you can put two chargers in parallel, if the charger allows for parallel chargers operation and has been properly adjusted. This will double the supply draw.

If the bottleneck is the BMS, then to use two BMS, you have to divide the pack into two parallel packs, each with one BMS. This is not simple and would entail separating the cells and is not practical.

Therefore if you wish to draw 15A, then purchase a pack, BMS, and charger rated for 1.65 kW. If you wish to draw 30A, then purchase 3.3 kW units.
 
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