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diy solar

Which BMS for my setup

Brent1982

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Sep 24, 2021
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Ok, new user, first post.

Setting up a system for my Caravan/RV (however you want to refer to it depending on which part of the world you're in).

Have purchased 8x 230ah EVE cells from Amy.

Have a Victron Multiplus 12/3000
12/12-30 orion-tr smart dcdc
2x Smart solar 100/50 mppt
6x 175w mono panels
cerbo gx with gx touch
Bmv-712.

Will have the batteries setup in 4S2P so I'm after recommendations for the bms's I'll need for both banks.

Biggest power users will be roof mounted reverse cycle aircon (dometic ibis 4) and a microwave.

Ive looked at the often mention Daly and JBD/Overkill models but unsure on any other options, or what to choose from those listed.

Any help would be greatly appreciated.
 
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So you want to have two 4s batteries each with there own bms in parallel for a 12 v system correct? I think that would be 4S2P, not 2P4S. That is exactly what I am doing and I bought two JBD150a 4s bms's from the JBD store on Aliexpress, but there are some US suppliers of these too. I am waiting for my 8 EVE 280ah cells. You could easily be pulling over 150 a with aircon and anything else on in the trailer, but split between the two bms's it should be OK. Realize with 230ah batteries you will not have a lot of reserve capacity for the aircon but if the sun is out with all those panels that will help.
 
Thanks for the reply. Have corrected my post.
With 460ah total, I figured it's enough to run the aircon for an hour or 2 in hot conditions and then resort to the abundance of efficient 12v fans in the van.

I'll check out the JBD150a bms on Aliexpress. Not sure whether shopping to Australia is quicker than what it is to you guys in the US
 
integration in the Victron system

1 control your pack true the cerbo gx and the see status of the pack

even if you don't do it now you have at least the possibility to do it in the future.
with a Daly 4s bms you don't have that and as i see it that will not be possible in the future ( sinowealth chip)

i own 2 Daly 200 ah bms and don't have a problem with them.

i will go for this.
https://www.aliexpress.com/item/1005002958135242.html go for the H (with heating 2 dollar more) version and order the serial cable with it so you can connect it to a computer and the cerbo gx

and some thing else watch out when you push around 250+ amps it is almost criminally insane ( but you have al ready a 12v/3000 watt inverter)
 
I have pretty much the same battery setup except 280ah cells. I have two 12v packs with JBD 150A BMS. I ordered the BMS units through the battery supplier for the 280's but I also ordered 2 JBD 150A BMS's from Jaibaida separately to use with 150A cells I have and also as backup in case there was an issue with the other order. They are two different styles but both report as JBD. Two are the long v1.5 style, two are the smaller units with full aluminum heat sink plate. The 2nd pair came air freight in two weeks to Canada
 
The Cerbo GX can be set up with a smart shunt and will monitor the voltage and state of charge of your combined battery pack and control your your multipluss and solar controller that way, without directly communicating with the bms's. However if you are trying to connect the bms directly to the Cerbo or Multipluss so the bms controls them I don't know if that can work with two BMS's. You could alternatively configure you battery as 2P4S with one 300 a bms. If you want the bms to directly control the multipluss there might be better BMS options out there and they might eliminate the need for Cerbo. I am implementing the first approach and not very familiar with the second, but the second approach has some advantages and there are others on the forum with more knowledge on it.
 
I have seen a lot on this forum say the overkill solar is the way to go if you are ok with fet type bms.
Then there is radio b like the jbd bms
 
Take a look at this thread for discussion of bms's with direct communication to your victron equipment

 
Yeah I don't think I need the bms to control the multiplus and other victron equipment. That's why I got the Cerbo Gx with the gx touch. I don't think I need to over complicate it that much.

Before purchasing the 8x 3.2v 230ah cells I was about to pull the trigger in 2 drop in 200ah lithium batteries that would have served the same purpose as the DIY packs I'm going to build. So all good in that sense.

Just after the best bms for taking care of each pack.
There is a solar shop in Melbourne, down the road from where I live who are a Victron reseller, and they build their own packs with CALB cells and use the Daly BMS.

So I guess at this point in time, it is between the JBD/Overkill and the Daly. As good as the REC bms looks, I think it is overkill for my needs.
 
"Yeah I don't think I need the bms to control the multiplus and other victron equipment. That's why I got the Cerbo Gx with the gx touch. I don't think I need to over complicate it that much."

Yeah in the end that's what I decided because I already had the victron equipment set up with my previous battery.
 
Yeah I don't think I need the bms to control the multiplus and other victron equipment. That's why I got the Cerbo Gx with the gx touch
The GX is always the one controlling your system. But the BMS with the driver that links to the GX give the GX the needed data to make the correct choices.

For instance the GX does not now the SOC% of the battery, or if one cell is having an overvoltage event. If you have the driver linking the BMS with the GX then the BMS informs the GX of this and the GX can manage the situation.

The battery data is also logged to your Victron VRM account, so you can see all the graphs and history. The battery will populate the DVCC settings, which the GX system use to manage the system, and raise alarms if needed and tell the chargers when to stop charging the batteries.
If the system is grid-tied as an ESS this will also stop your battery being depleted past the minimum value you set up. For off-grid the GX will ignore that minimum setting.

PS. Most of the BMSs that my driver support work very well. However the Daly have not kept up with the competition and their hard coded settings for when to start balancing cells and when a cell overvoltage happens have caused many issues to some users. If I had to choose between JBD and Daly, the JBD is a far better choice.
 
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