Choosing a BMS for 48V Golf Cart Battery Project

Roland W

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Oct 9, 2017
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I live on the gulf coast so it's super humid hear and the dehumidifier runs quite a bit. The specs show a max of 8A and 920 watts, so it doesn't seem like it would take a massive powerwall to drive it.
Yeah, sound much easier to begin with. Maybe plug that dehumidifier into a wattmeter for a few days and see how much energy it draws during a day. that would give you a rough idea on how much energy you need to store for it.
 

Doc3G

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Apr 18, 2021
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Yeah, sound much easier to begin with. Maybe plug that dehumidifier into a wattmeter for a few days and see how much energy it draws during a day. that would give you a rough idea on how much energy you need to store for it.

OK, I've got a Kill-a-watt meter, that should get the job done? I ultimately want to build a powerwall and full solar for the house but I won't know where I'm going for residency for another 18 months or so. I plan to rent this house out if we have to move for residency and I'm not sure I want to deal with a rent house with full solar (honestly, I don't want to deal with a rent house at all, I'd prefer to stay here for residency).
 

floydR

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Aug 23, 2017
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Yes Killawatt meters work good. input what you pay per kwh and can be moved to different locations/ appliances find out what costs the most to operate.

Later floyd
 

emoney

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Apr 19, 2021
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In my case, I did it just the opposite; I built batteries for my golfcarts before tackling the Powerwall. I plan to build a system for back-up/emergency power at the house as I, too, live on the Gulf Coast but in Florida.
 

Doc3G

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Yes Killawatt meters work good. input what you pay per kwh and can be moved to different locations/ appliances find out what costs the most to operate.

Later floyd

So, I went up into the attic to plug in the killawatt and the cable and outlet are 20A plugs (I think the term is 5-20P, with one sideways prong) even though the unit is stated to only draw 9.6 amps. I tried searching for a compatible killawatt devices and didn't have any luck. Can I just use a clamp meter to figure out what the 100% load would be?
 

floydR

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What do you have on that outlet? the Killawatt mesures how many amps you use connect an appliance ( a tv, refrigerator, stereo etc and it will tell you how much you are using .
The outlet doesn't have to output 20 amps. Check the voltage of the outlet, a long time ago at friends parents house supposedly they had an 5-20 outlet wired to 220v. Don't know how true this was. as I said this was along time ago

Later floyd
 

OffGridInTheCity

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So, I went up into the attic to plug in the killawatt and the cable and outlet are 20A plugs (I think the term is 5-20P, with one sideways prong) even though the unit is stated to only draw 9.6 amps. I tried searching for a compatible killawatt devices and didn't have any luck. Can I just use a clamp meter to figure out what the 100% load would be?
You could get a 20a (side-ways) plug conversion to a regular plug as well and then the killowatt would plug in.
Or you could replace the receptacle with a dual side/straight 20a receptacle like this:
1619186446858.png
 

Doc3G

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Apr 18, 2021
Messages
56
What do you have on that outlet? the Killawatt mesures how many amps you use connect an appliance ( a tv, refrigerator, stereo etc and it will tell you how much you are using .
The outlet doesn't have to output 20 amps. Check the voltage of the outlet, a long time ago at friends parents house supposedly they had an 5-20 outlet wired to 220v. Don't know how true this was. as I said this was along time ago

Later floyd

It's a dedicated circuit for the dehumidifier, so there is no other draw on it. It is 110v, so, given that the unit is rated for 9.6A and the Kill-A-Watt can handle 15A, it should be safe to just get a conversion plug as OffGrid suggested?
 

Doc3G

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Joined
Apr 18, 2021
Messages
56
You could get a 20a (side-ways) plug conversion to a regular plug as well and then the killowatt would plug in.
Or you could replace the receptacle with a dual side/straight 20a receptacle like this:
View attachment 24778

Thanks, I'm probably going to try this since the dehumidifier seems like the best target to start with to start using solar.
 

floydR

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Aug 23, 2017
Messages
1,148
It's a dedicated circuit for the dehumidifier, so there is no other draw on it. It is 110v, so, given that the unit is rated for 9.6A and the Kill-A-Watt can handle 15A, it should be safe to just get a conversion plug as OffGrid suggested?
Yes it would be safe to get a conversion plug, I thought it was like the outlet offgrid posted which accepts both style of 120v plugs.
Later floyd
 
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