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Need a Lithium Battery Charger for initial charge.... recommendations?

Wildman13

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Aug 30, 2021
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Hello group. I'm picking up my 2 SoK 206ah Lithiums on Monday and then need to charge them. I'm picking up the rest of the system for install Tuesday/Wednesday. I full time and will have solar or a genny to always charge the batteries so I don't for-see ever needing to use the charger again. We also have very limited storage space being it's a 21' trailer. I would prefer not to buy a $200-$300 charger for a 1 use activity if I can help it.

I will be plugging the charger into a regular outlet while the RV is plugged into 30amp shore power OR a friends house if you dont think the 30amp will be enough. We will be living in the RV while the batteries would be charging.

thanks
 
I have the same two SOK batteries. I bought a Victron Energy Blue Smart IP67 12V 17A charger. $132. Depending on the SOC of the batteries it will likely take half a day or so to fully charge the batteries. My batteries are in series so I figure I will use the charger once a year to rebalance the two batteries together in parallel.
 
I have the same two SOK batteries. I bought a Victron Energy Blue Smart IP67 12V 17A charger. $132. Depending on the SOC of the batteries it will likely take half a day or so to fully charge the batteries. My batteries are in series so I figure I will use the charger once a year to rebalance the two batteries together in parallel.
Thanks! SoK said they are shipped at 30% soc so 8 hours each it looks like. I'll also be running in series but watts 247 has a battery balancer that you can install for cheap that keeps them always balanced he says.
 
I would spend nothing and jump off the existing 12v supplied by the RV. Is there something special going on here?
 
I have the same two SOK batteries. I bought a Victron Energy Blue Smart IP67 12V 17A charger. $132. Depending on the SOC of the batteries it will likely take half a day or so to fully charge the batteries. My batteries are in series so I figure I will use the charger once a year to rebalance the two batteries together in parallel.
I just got everything today and going to start charing up the batteries tomorrow. I have a few question on the charger.

1. I remember watching an episode that Will Prowse did and he said not to over charge the batteries initial charge. I don't remember what he was referring to though. Can I just plug in the IP67, select lithium and walk away and come back hours later or do I need to monitor it?

2. In that same episode Will mentioned setting the charge to 3.6v i think (it was on some raw cells he built) Victron instructions just mentions a lithium setting.

3. After batteries are charged I just put both on charger in parallel to top balance. Do I need to select any different setting or just the lithium again and let it do it's thing?

Thanks, don't want to mess up $2k in batteries and driving across the country for the last 8 days has me a little worn out lol.
 
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Most of the complicated process is for assembling individual cells into a battery. This part is done for you.
I would parallel charge them to 14.2-14.6 and put them in service (24v). Yes the standard lithium setting should be fine.
 
I would spend nothing and jump off the existing 12v supplied by the RV. Is there something special going on here?
Yes.

It's not usually a good idea to connect batteries of very different soc together. They may be close, but if they have different voltage you get current between them when you make the hookup.

Best to minimize that as much as possible.
I just got everything today and going to start charing up the batteries tomorrow. I have a few question on the charger.

1. I remember watching an episode that Will Prowse did and he said not to over charge the batteries initial charge. I don't remember what he was referring to though. Can I just plug in the IP67, select lithium and walk away and come back hours later or do I need to monitor it?

2. In that same episode Will mentioned setting the charge to 3.6v i think (it was on some raw cells he built) Victron instructions just mentions a lithium setting.

3. After batteries are charged I just put both on charger in parallel to top balance. Do I need to select any different setting or just the lithium again and let it do it's thing?

Thanks, don't want to mess up $2k in batteries and driving across the country for the last 8 days has me a little worn out lol.
1: set it to lithium and forget it.
If you want to get advanced you may be able to manually configure settings but that gets pretty up there in complexity.

2: that was regarding individual cells, not a complete battery.

3: you can just stick them in parallel at that point. If you want to put both of them on one charger to parallel top balance you can, or just stick them into the trailer and call it a day.

Whether it even can top balance them kind of depends on the bms settings of the batteries themselves. They may cut out fairly low to provide maximum life.
 
Most of the complicated process is for assembling individual cells into a battery. This part is done for you.
I would parallel charge them to 14.2-14.6 and put them in service (24v). Yes the standard lithium setting should be fine.
I don't know if OP is using them in series though. The next comment was.
 
I just got everything today and going to start charing up the batteries tomorrow. I have a few question on the charger.

1. I remember watching an episode that Will Prowse did and he said not to over charge the batteries initial charge. I don't remember what he was referring to though. Can I just plug in the IP67, select lithium and walk away and come back hours later or do I need to monitor it?

2. In that same episode Will mentioned setting the charge to 3.6v i think (it was on some raw cells he built) Victron instructions just mentions a lithium setting.

3. After batteries are charged I just put both on charger in parallel to top balance. Do I need to select any different setting or just the lithium again and let it do it's thing?
I set the charger to Li-ion. The defaults at that point should be fine.

Wire the two batteries in parallel. Use wire at least as thick as the charger leads. Make both wires the same length. Connect the charger. Put the positive charger lead on one battery and the negative charger lead on the other battery. You don't want the charger connected directly to just one of the two batteries.

Let the charger run until it goes into storage mode. It's fine if that happens during the night. The charger won't overcharge if left unattended.

After disconnecting the charger I left the two batteries connected in parallel for half a day just to make sure the two had the exact same SOC. At that point they are ready to be connected in series for your 24V system.
 
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