Let's talk battery capacity

[kfwbird]

I am putting a new 800 watt solar system on my 29RS in March. I have been shopping for batteries. I was considering getting two 200Ah batteries, but just saw these Chins on Amazon. I could get two of these 300Ah batteries for a similar price. Is there a downside to this plan? Anybody else have a better idea? Thanks.

https://smile.amazon.com/LiFePO4-Bat...08FMVRJHZ&th=1

[Scramjet]

Cheap lithium batteries are definitely a high dollar risk. They are sometimes poorly assembled, sometimes have inadequate wiring and possibly a poor quality BMS which is the fail safe system on a good quality system. I would not invest that kind of money in an unproven battery.

[GeoffnCheri]

Will Prowse does some excellent battery reviews and comparisons on his YouTube channel. You may wish to spend some time on there. He does recommend other batteries beside BB.

https://www.youtube.com/channel/UCoj...q8kmJme-5dnN0Q

[bertschb]

I wouldn't buy any LiFePO4 battery that I hadn't seen torn down and tested.

[A.Texas.Yankee]

I would be concerned with that unit being made with grade b cells and also question the quality of the internal construction. BMS is also a concern. Not saying it's of poor quality, just stating it's an unknown.

Chinese isn't necessarily a bad thing. I'm waiting on Chinese cells to build a DIY 900ah 12v battery bank. The cells are grade A and new and after BMS, I'll have paid about $2300 total for the bank. Will have to wait a few months, though. It's a bit above a quick DIY, but I'll save thousands over the pre-built units (and forgo any stateside warranty).

Sent from my SM-N986U using Tapatalk

[SolarPoweredRV]

I am putting a new 800 watt solar system on my 29RS in March. I have been shopping for batteries. I was considering getting two 200Ah batteries, but just saw these Chins on Amazon. I could get two of these 300Ah batteries for a similar price. Is there a downside to this plan? Anybody else have a better idea? Thanks.

https://smile.amazon.com/LiFePO4-Bat...08FMVRJHZ&th=1

Have you read my post about "Cheap Batteries are Coming..."? Your question is exactly the point I was making in the post.

There are a couple of advantages to buying these batteries as opposed to buying the cheapest batteries direct from China. The main advantage is they are available now versus waiting for 8 weeks to get them shipped direct from China. The other advantage is that if they are defective, you could get them replaced quickly because of Amazon's return policy.

One of the ways to look at whether you are getting a good deal or not, is to compare the cost per 100 amp hours to the cost of a 100ah Battle Born battery. In this case you are paying $428 per 100 ah. Is saving ~ 50% on your batteries worth it to you?

Based on the fact you can buy them from Amazon, and you can get them and test them immediately. I would probably buy these batteries, test them and return them if they don't meet your expectations. If they test well, then they will probably last the full 10 years of their warranty, however, I would also be aware that the warranty may not be worth the pixels that it is printed on.

Two technical notes: depending on how high your expected current draw will be, you may be better off buying 3 - 200ah batteries versus 2 - 300ah batteries to reduce the current draw from each battery. The reason I recommend this is to reduce the chance of over heating the internal battery components in a high current draw installation.

Also, is there any way you could increase your Solar wattage? It seems that 800 Watts might be a bit light for a 600ah battery bank. Maybe you could get higher wattage panels in the same sized panel or maybe even bigger panels if you have roof space available.

Please keep us informed as to which batteries you choose and how well your choice works out.

[SolarPoweredRV]

I would be concerned with that unit being made with grade b cells and also question the quality of the internal construction. BMS is also a concern. Not saying it's of poor quality, just stating it's an unknown.

Chinese isn't necessarily a bad thing. I'm waiting on Chinese cells to build a DIY 900ah 12v battery bank. The cells are grade A and new and after BMS, I'll have paid about $2300 total for the bank. Will have to wait a few months, though. It's a bit above a quick DIY, but I'll save thousands over the pre-built units (and forgo any stateside warranty).

Sent from my SM-N986U using Tapatalk

Please let us know how much you save by going this route and how well the batteries perform.

[A.Texas.Yankee]

Please let us know how much you save by going this route and how well the batteries perform.

I sure will. I can say I am confident in the sale so far. Went through Alibaba through one of the recommended sellers from Will's DIY Solar forum and the level of service I've received from the seller so far is fantastic.

If all goes well, I will have saved about $6,500 over a similar sized Battleborn buy (9 baterries of 12v @ 100ah @ $950/ea, respectively).

I am including the cost of BMS, frieght to texas, and cells as well as the equipment I'll need to top balance and test the cells. Lots more work, but I like projects.

Sent from my SM-N986U using Tapatalk

[kfwbird]

Have you read my post about "Cheap Batteries are Coming..."? Your question is exactly the point I was making in the post.

There are a couple of advantages to buying these batteries as opposed to buying the cheapest batteries direct from China. The main advantage is they are available now versus waiting for 8 weeks to get them shipped direct from China. The other advantage is that if they are defective, you could get them replaced quickly because of Amazon's return policy.

One of the ways to look at whether you are getting a good deal or not, is to compare the cost per 100 amp hours to the cost of a 100ah Battle Born battery. In this case you are paying $428 per 100 ah. Is saving ~ 50% on your batteries worth it to you?

Based on the fact you can buy them from Amazon, and you can get them and test them immediately. I would probably buy these batteries, test them and return them if they don't meet your expectations. If they test well, then they will probably last the full 10 years of their warranty, however, I would also be aware that the warranty may not be worth the pixels that it is printed on.

Two technical notes: depending on how high your expected current draw will be, you may be better off buying 3 - 200ah batteries versus 2 - 300ah batteries to reduce the current draw from each battery. The reason I recommend this is to reduce the chance of over heating the internal battery components in a high current draw installation.

Also, is there any way you could increase your Solar wattage? It seems that 800 Watts might be a bit light for a 600ah battery bank. Maybe you could get higher wattage panels in the same sized panel or maybe even bigger panels if you have roof space available.

Please keep us informed as to which batteries you choose and how well your choice works out.

Thank you for your advice. I had read your article and viewed your spreadsheet about the value of these cheaper Chinese batteries. I might just drop back to 2-200ah batteries as I am at my price-point for this system. I liked these Chin batteries because they have a facility in California (along with a 10-year warranty). I will be happy to let you know how things go. I am also purchasing this solar kit. https://www.continuousresources.com/...840w-solar-kit Any suggestions are appreciated. I am a completely new to this, but have watched many you-tube videos.

[kfwbird]

This Will Prowess video seems to argue in favor of having the 600AH (rather than 400AH) but not charging the batteries all the way to increase the life of your battery. https://www.youtube.com/watch?v=Yf9N9zBgyB8