In short
- Each pack needs its own address; set the switches according to your battery manual.
- After changing a switch, reset the BMS: the new address does not count before that.
- Compare the packs regularly: a pack that drifts or stops responding rarely announces itself.
Two racks in parallel must do two separate things: share the power through heavy cables, and share information through thin ones. The information side is what this guide is about. Always follow the manual of your battery for the power side and for its limits on the number of packs.
The link cables
Packs are usually chained with straight RJ45 network cables between their link sockets, from one pack to the next. A cable that has been crimped by hand or a plug that is not fully home can bring the whole conversation down, so test with a known good cable first.
The address switches
The row of small switches gives each pack its number on the bus. The pattern differs between battery brands, so use the table in your own manual. Two packs with the same address, or a master pack that is not set the way the manual says, are the classic causes of a bank that behaves strangely.
The reset everyone forgets
Moving a switch is not enough. The board reads its address at start-up, so reset the BMS after each change. Many “it does not work” stories end here.
Which pack talks to the inverter
In most setups, the inverter is connected to the master pack, which reports for the whole bank. If you see the capacity of one pack on the inverter instead of the total, the chain or the addresses are the first things to check.
Watching the bank
An inverter shows one percentage for everything. It can hide a pack that charges less than the others or has dropped out of the chain. Pace Monitor shows each pack on firmware that reports the chain, and the dashboard puts them side by side. Tell us how many packs you have when you order, and we test that case before shipping.
Common questions
Do all packs need the same firmware?
Identical firmware is the safest option. Ask your seller before mixing old and new units, since some versions do not work well together.
Is an ordinary network cable enough between packs?
On most racks, yes, as long as it is a straight cable in good condition. Check your manual: some makers supply a specific one.
Can I add a new pack to an old bank?
Often yes, but a new pack will not match an aged one at first. Ask your seller, and watch the packs closely during the first weeks.
