gathering supplies to make charger cables

[Opaline]

I'm gathering the items I need to make Anderson connected charging cables/wiring and have a few queries that I'm hoping someone can assist with...

I have MK M34SLDG batteries in my chair, the spec says they have type C terminals that are 1/4"-20. Am I correct in thinking I need M6 ring terimals?

Do people use authentic Anderson connectors or Anderson-type connectors?

What wire diameter is best? My current crimp/wire stripper tool only goes up to 10AWG, I'm thinking that might not be big enough?

Finally, I'm looking at buying the IP22 victron smart 24V charger that does 8/12/16 A charging, if I put a fuse on the cables from the charger do I need on on my chair too? I'm thinking not, but want to be safe. What size fuse would be best, is 20A sufficient?

Thank you in advance, I'm super grateful to all you knowledgeable people.

[Burgerman]

The battery is american, so it has 1/4 x 20 tpi bolts. Yes thats very close to stock 6mm thread diameter. So 1/4 or 6mm ring terminals are fine.

The fuse wants to be in the battery cable rather than the charge lead. The fuse size is to protect the wires. Not the battery. So its size needs to be matched to your cables.

Having a 24V anderson, and I use generic and genuine interchangably, means you can discharge or charge at anything up to 100A. For e.g an AC inverter, or whatever. And any charger up to 100A. So that would need 10sqmm cables. If you are only interested in charging at 20A you need say 20A fuse and cable rated for 20A.

You do that by using a simple formula! Thats means a cable can carry 25A if its 2.5 sq mm cross section. So you would want cables bigger than this. Say 4mm. Those are 40A capable. But you want headroom.

[Opaline]

brilliant thank you, that makes sense. I assume the fuse goes closer to the Anderson connector than the battery to keep the amount of wire without protection low?

I think I'm going to buy 10mm*2 tinned cable and future proof myself in case I decide to buy a bigger Amp charger later on. If the Anderson connector is rated for 50A does that not need protection and limit the size of the fuse you put in the cable? (I might be over thinking this....)

[Burgerman]

No next to the battery. You are trying to prevent a short on a cable, for e.g causing a fire by melting a trapped chafed wire. If the fuse is at the anderson end you can short the battery out somewhere with no fuse in its path...

Andersons are easily capable of 100A. They are hot plugable at 50A. So 10sqmm cable and 100A fuse at the battery end is great.

[Opaline]

ah yes, of course, the power's coming from the charger not the battery when you're charging (d'oh, obvious when I stop overthinking)

[Burgerman]

When charging the charger can only provide 16A? The cables can stand that or up to 100A. So no fuse needed. The charger itself limits current. When you short out the chairs battery cables 1500A or more will flow. And result in a fire or spectacular fireworks.

The charger ALSO should have a fuse in its cable, rated for the charger cable capability. Because when that is connected to the chair, a shorted cable between charger and chair will allow 100A via the chairs fuse to flow in the shorted charger cable. And again fireworks, but most people dont bother. Because you can see that cable and it wont set fire to the chair you are sat on! If you put a fuse in the chargers cable it needs to be at the anderson end. Because the charger cannot burn its cable. The battery can.

[Opaline]

yes, charger I'm planning to buy is up to 16A. With the victron ip22 [url]https://www.victronenergy.com/chargers/blue-smart-ip22-charger[url] you make your own cables that go into screw terminals. I was planning to use the same 10mm*2 cable on the charger with a 70A fuse on the positive cable (every listing for 10mm*2 cable that I've found says max 70 or 75A) with an Anderson connector on the end. I'd rather use a fuse in the charger cable for peace of mind.

Then for the chair, same type of cable attached to an Anderson connector, with 70A fuse on positive wire to be attached to battery (and obviously a matching negative cable but without fuse). As the batteries are already in series in the chair I believe I just have to use my multimeter to find out which postive and negative terminals give +24V and connective positive Anderson lead to that positive terminal and negative Anderson lead to matching negative battery terminal?

I'd draw a circuit diagram but can't find an easy to use free online program..

I really appreciate your patience, thank you.

[Burgerman]

10 mm2 is huge overkill on a 16 amp charger though. Heavy, stiff, and at least 4x bigger than needed. Some 2.5mm cable is perfect and still about double what is needed. That would need at 20A fuse.

Yes pos to pos, neg to neg. Preferably soldered not just crimped.

[Pierro]

Did I understand that correctly?

The cable, which goes from the control unit to the battery pack, is cut through (roughly speaking) and both ends get an Anderson. To charge the batteries, the control unit is unplugged and the Anderson of the charger is plugged in on the battery side?

@Opaline, I would be very happy about a circuit diagram.

[Burgerman]

The cable, which goes from the control unit to the battery pack, is cut through (roughly speaking) and both ends get an Anderson. To charge the batteries, the control unit is unplugged and the Anderson of the charger is plugged in on the battery side?

Definitely not! Nothing happens to existing cables or connetions.

[shirley_hkg]

The other end of your Anderson cable has ring terminal which goes to battery post directly.

[Pierro]

The cable, which goes from the control unit to the battery pack, is cut through (roughly speaking) and both ends get an Anderson. To charge the batteries, the control unit is unplugged and the Anderson of the charger is plugged in on the battery side?

Definitely not! Nothing happens to existing cables or connetions.

I got that. I was only concerned with the way where the charger is connected.

Thank you @shirley_hkg.

I have learned so much from this forum. Thank you all for your patience with me.

[Burgerman]

Heres a more complex version. More advanced. It requires a little more knowledge.

This allows you to charge them or drain them by using any 12V appliances such as ac inverters, powertools etc in parallel. It also allows you to charge or drain them at 24V too.

So you can also charge at 12V in a vehicle from the cars charge system at around 50A or so rapidly falling to almost nothing as it charges. Or start your car if battery low, or charge with a 2x 12V marine charger, or any 12V or 24V charger. The chair with the loop removed has no power and will not turn on. So great to isolate the batteries when not in use so that instead of charging avery 2 weeks to keep batteries topped off, you only need do it every 3 months. Because the residual drain current that the chairs control system takes when off is gone.

Many advantages.

Here. A very old page! Older than some readers here.
https://www.wheelchairdriver.com/faster ... arging.htm

[Burgerman]

The more complicated version... 12v or 24 you decide!
https://www.wheelchairdriver.com/faster ... arging.htm
If you dont fully understand this page dont do it. Get it wrong and thousands of amps and melted cables happen in 2 seconds.

And where it says use different colours andesons, you cant, the colours are keyed differently. So mine are all grey. On every charger, inverter, tool, mower, polisher, solar, etc. Even my electric bed. And all my hobby chargers inputs. And van.