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EG4 LiFePO4 in defies

trentonkfletcher

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So the EG4 lithium battery used in the budget build is 200AH. If you were to combine a different brand like the Weize 100AH (budget) with it in series to reach 300AH, would that be a problem and would it still be okay to use with the 24V Growatt all-in-one system? I’m doing a fully off-grid skoolie conversion and figure I would need 300AH to feel confident in it.
 
Doesn't work like that. Adding the battery in series would not increase your bank to 300aH. It'd increase your voltage. You'd want to add your new battery bank in parallel. You have to be a bit careful here as you do want the additional battery to be of the same chemistry (eg Lifepo4 or Li-Ion or Lead Acid). Make sure both batteries have their own BMS.

Alternatively, you could have a transfer switch to switch to the extra 100aH battery in the event you need it.

Since you're going to be in a schoolie, I recommend adding in a DC-DC charger to take advantage of the school bus's alternator as a source of charging in the even you over deplete your bank or if there's not enough sun.
 
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Doesn't work like that. Adding the battery in series would not increase your bank to 300aH. It'd increase your voltage. You'd want to add your new battery bank in parallel. You have to be a bit careful here as you do want the additional battery to be of the same chemistry (eg Lifepo4 or Li-Ion or Lead Acid). Make sure both batteries have their own BMS.

Alternatively, you could have a transfer switch to switch to the extra 100aH battery in the event you need it.

Since you're going to be in a schoolie, I recommend adding in a DC-DC charger to take advantage of the school bus's alternator as a source of charging in the even you over deplete your bank or if there's not enough sun.
Okay that’s my mistake, in parallel, not in series. I must’ve been in a hurry typing that up because that’s something I’d make sure is correct when hooking it up. As for the extra battery, it’d definitely be another LiFePO4; probably the Weize 100AH. I’m just trying to find a way to use that budget system in the video and upgrade it to the recommended 300+AH battery bank blueprint from the website. My main concern is if the Growatt inverter would still work or if I would need a larger inverter than that one
 
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Okay that’s my mistake, in parallel, not in series. I must’ve been in a hurry typing that up because that’s something I’d make sure is correct when hooking it up. As for the extra battery, it’d definitely be another LiFePO4; probably the Weize 100AH. I’m just trying to find a way to use that budget system in the video and upgrade it to the recommended 300+AH battery bank blueprint from the website. My main concern is if the Growatt inverter would still work or if I would need a larger inverter than that one
An inverter doesn't care what your batteries are as long as they have enough power. You can grow your battery bank as large as you want(keeping it the same voltage) and keep the inverter and or charger the same (Growatt is all in one). The inverter would only need to "grow" if you plan on more AC loads. If you're on a budget, I'd recommend just building your own battery bank. I'd personally go with (8) 304aH 3.2V LifePo4 cells from China for a 24V system wired up to a basic JBD BMS. You can then use the growatt 3000W 24V inverter / charger system with this battery bank. You could even go bigger and badder if you go with the same cells but with 16 of them for a 48V setup.I'm not sure if Growatt has a 48V version.
 
So the EG4 lithium battery used in the budget build is 200AH. If you were to combine a different brand like the Weize 100AH (budget) with it in series to reach 300AH, would that be a problem and would it still be okay to use with the 24V Growatt all-in-one system? I’m doing a fully off-grid skoolie conversion and figure I would need 300AH to feel confident in it.
Assuming the EG4 battery you have currently is a 24v battery, you would have to have two (2) of the 12v 100ah Weize batteries (in series) to parallel with the EG4.
 
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