Parallel Wiring with Anderson Connectors

[dirtybobby423]

The batteries I recently purchased (24v LifePo) come with an Anderson Connector output already wired in. My question is what is the best way to connect 3 of these batteries in Parallel?

I have spare Anderson connectors, can I make pigtails? Can I simply connect the three + and three - cables together and then run it to the charge controller? Do the lengths of wire matter?

Appreciate your thoughts in advance!

 

[BiduleOhm]

Yes, and yes.

Ideally you want the wires to be the same length, see here for more info

 

[chrisski]

Does the battery amperage exceed the Anderson Plug rating to include however they are put in series parallel?

I’d be curious about the amperage on the Anderson Pole Connectors. I have some Anderson Pole Connectors on some 10 AWG and 12 AWG wire, and those are rated for 45 amps and I am making cabling for that, but those connections won’t go over 30 amps. I wanted to get some 6 AWG wire to send this 30 amps more than a 10 feet without loss and those were 75 AMP Anderson Power Poles.

The company I got my panels from that have these Anderson Powerpoles seems to have put these in to make using their equipment easy, or to force me to buy their stuff. If I use the panels as not intended, I void the warranty. In this case, if I hooke these panels up in series instead of in parallel, I void the warranty.

 

[BiduleOhm]

Yes, of course you need to stay within the connector ratings.

But it shouldn't be a problem here as from his description he would only have the connectors on the battery side, the other side of the wires would be connected to the charge controller

 

[chrisski]

I’ve got to admit I’m not familiar with the 24 volt battery he’s talking about, but if its anything like powering my RV, I would easily be pulling more from than the smaller Anderson Plugs could handle. I’m thinking one battery may be designed to flow 20 amps, but three together is 60 amps, which is still fine as long as its not an additinal Anderson Plug to the charge controller.

 

[John Frum]

There are very high current anderson connectors.
I don't think @dirtybobby423 said which ones he has.

 

[dirtybobby423]

There are very high current anderson connectors.
I don't think @dirtybobby423 said which ones he has.

Thanks guys. These are the batteries I am using.

24V – A123 LiFePO4 Battery Box – BigBattery.com

bigbattery.com

They are using SB175 connectors, so 175amp rating. Bigbattery sells parallel wiring kits for these that are use #6 wire. I have other SB175 connectors and was planning on using #4 wire to make the parallel connections.

The reason I didnt purchase the premade ones was it seemed like there would be alot of slack in the cables. Most of the other applications I see have very short lengths of wire connecting the batteries.

There will not be an SB175 connector on the charge controller side.

So that all being said, is #4 wire big enough? Is there anything else to look out for other that trying to keep the cable lengths short and equal length?

 

[dirtybobby423]

Yes, and yes.

Ideally you want the wires to be the same length, see here for more info

Appreciate this link, thanks.

 

[John Frum]

Thanks guys. These are the batteries I am using.

24V – A123 LiFePO4 Battery Box – BigBattery.com

bigbattery.com

They are using SB175 connectors, so 175amp rating. Bigbattery sells parallel wiring kits for these that are use #6 wire. I have other SB175 connectors and was planning on using #4 wire to make the parallel connections.

The reason I didnt purchase the premade ones was it seemed like there would be alot of slack in the cables. Most of the other applications I see have very short lengths of wire connecting the batteries.

There will not be an SB175 connector on the charge controller side.

So that all being said, is #4 wire big enough? Is there anything else to look out for other that trying to keep the cable lengths short and equal length?

If you are paralleling them using the posts method from wiring unlimited the wire only needs to be 6 awg to the posts.
from the posts it depends how much current you plan for.

 

[dirtybobby423]

If you are paralleling them using the posts method from wiring unlimited the wire only needs to be 6 awg to the posts.
from the posts it depends how much current you plan for.

Thanks, I think I will use the 4awg I have to a busbar and 1/0 from there to the charge controller. Seems like that should be more than sufficient.

 

[Yonkk]

Same here with 175 anderson connectors only 12v, wanting to parallel connect two 12v 170ah batteries. So 2awg wire both batteries 12v 170ah batteries on all anderson connectors to + and - 3/8 bus bars then to + on & off switch then to 5/16 bus bars.

 

[mattleonard]

I also use SB175 connectors for a modular setup - with (4) 12v 105ah LifeP04 batteries, wires in series for a 24v setup. The best option is to connect batteries to a busbar using equal length-cables, and then the SB175 from there to your load. Since I sometimes use just a pair of batteries, I'm about to actually put a busbar on the load side run and have separate SB175's on each pair of batteries.

SB175 are typically 1/0 cable, but they do make a 2/0 lug option, and it's conceivable you could crimp two leads into the one sleeve to make a "wye" cable (single SB175 on one end, two SB175's on the other end), but I doubt dual 1/0 cable would fit. I have done this with SB50's - to create a wye with (4) Power Pole 45's on the other end, but that was using 8g.

If you don't want to use a busbar, this is an option, but you might need a longer Anderson pigtail to have each lead on a different physical battery.

 

[Bob142]

Just an FYI on Anderson SB connector series current limits since I see this come up in a lot of threads here.
Most people assume the number in the connector model name is max current. It’s not. For example, SB 50 series is UL rated to 120A, and SB 175 is UL rated to 280A.

Anderson SB Series Connector Specs

Links to the Anderson Power Products resource page for the SB series of connectors. Provides information on the SB50, SB120, SB175, and SB350 connectors including links to download the full datasheets. Don't assume the number in the product name...

diysolarforum.com

 

[chrisski]

Here's two things I want to add to my signature block:

1) How to parallel batteries: http://www.smartgauge.co.uk/batt_con.html.

2) Wire Size Calculator: https://www.calculator.net/voltage-drop-calculator.html

 

[mattleonard]

Just an FYI on Anderson SB connector series current limits since I see this come up in a lot of threads here.
Most people assume the number in the connector model name is max current. It’s not. For example, SB 50 series is UL rated to 120A, and SB 175 is UL rated to 280A.

Anderson SB Series Connector Specs

Links to the Anderson Power Products resource page for the SB series of connectors. Provides information on the SB50, SB120, SB175, and SB350 connectors including links to download the full datasheets. Don't assume the number in the product name...

diysolarforum.com

Yeah -for instance the SB175 nomenclature is rating for 1/0 wire per CSA (Canadian), or 3 pole 1/0 UL. I'm sure the vast majority of users, especially in this forum - are just using the 2-pole.

 

[schmism]

I prefer this method as its easy to ensure that all the cables are the same lenght. Its also easy to remove a battery or add additional batteries in the future.

 

[chrisski]

I prefer this method as its easy to ensure that all the cables are the same lenght. Its also easy to remove a battery or add additional batteries in the future.

What do you use to connect all the positive wires together?

If I go with more batteries, this is what I’ll use, and I plan on busbars with five posts. Not sure if it’s practical to put multiple wires on a single post on a busbar. Seems like a good idea until the wires are cut and crimped with 3/8 lugs and then its like a puzzle.

 

[Yonkk]

Connected my Big Battery PowerBlocks in Parallel. Using my small power station in the winter for power outages. In the Spring it will go in my Ford Connect Van and add some solar panels for going on camping trips.

 

[dirtybobby423]

I also use SB175 connectors for a modular setup - with (4) 12v 105ah LifeP04 batteries, wires in series for a 24v setup. The best option is to connect batteries to a busbar using equal length-cables, and then the SB175 from there to your load. Since I sometimes use just a pair of batteries, I'm about to actually put a busbar on the load side run and have separate SB175's on each pair of batteries.

SB175 are typically 1/0 cable, but they do make a 2/0 lug option, and it's conceivable you could crimp two leads into the one sleeve to make a "wye" cable (single SB175 on one end, two SB175's on the other end), but I doubt dual 1/0 cable would fit. I have done this with SB50's - to create a wye with (4) Power Pole 45's on the other end, but that was using 8g.

If you don't want to use a busbar, this is an option, but you might need a longer Anderson pigtail to have each lead on a different physical battery.
View attachment 26846

I was able to create my own anderson parallel cables by using different sized contacts inside the connectors. Powerwerx sells the contacts for wire sizes 6 through 1/0. For two 4 gauge wires I used a size 2 contact, which fit nice and snug and soldered up great.

 

[Living hakuna]

I'm getting 4 24V @170 batteries, connect then in series (48V) and parallel (340Ah). They use an Andreson 175 connector so to get 3cables in 1 connector is impossible when using (1/0 gauge) cables so I will be connecting them like this Using bus bars