I noticed one of the other members had moved the main cut off switch to the outside of the battery compartment next to the charger plug in. This makes sense to me. In an emergency you shouldn’t have to lift up the seat to get to the switch. Also it makes it convenient to disconnect the batteries from the circuitry if you want to park the GEM a couple of weeks with the charger unplugged. If you move the switch next to the AC input you can use the existing wiring to wire it up. No cutting necessary. The plastic seems more than robust enough to safely attach the switch. What do you think?
I have moved all of ours out from under the seat for added safety. I also changed the wiring so that the switch is on the end of the string of six batteries. This allows me to, in an emergency, charge the GEM while doing electrical repairs at the same time.
Daniel
Daniel, where in the wiring did you insert the cutout switch? It should either disconnect the most negative or the most positive wire I’d think. Did you put it in the long wire which goes to the driver’s (left) side or another cable? Many older GEMs have 4 batteries under the seat and 2 more under the hood. I’m not positive of which one is the grounded (most negative) battery cable or the most positive (72 volts) cable.
Our main switches are opposite the side with the AC plug. I found no way to relocate without making new battery cables. The switch is connected to the NEG end of the battery string. There are several reasons why I did them this way. We added two 36 volt EZ-GO golf car power connectors to allow off board charging. There is a thread on this forum covering off board charging and its advantages. I also use these same 36 volt connectors for DC welding. Yes, the batteries in the GEM can be used for arc welding! Placing the main switch at the end of the battery string allows this by isolating the GEM electronics for the welding current. Third, and most important, the switch is moved to be accessible for safety reasons.
Daniel
I assume the OEM placement is designed to cut the pack down the middle. Similar safety cutouts are used on Toyota hybrid battery packs. There’s a jumper plug located in the service lever that opens the circuit between the two halves of the battery pack. Theoretically this reduces the chance of a short-circuit by cutting the apparent voltage to ground in half.
I’m with you though - the best way to do it is to cut the positive 72 volt cable between the last battery and the main contactor. If you install a Batt-Six monitor this is essential to prevent damaging the voltage monitor circuitry when opening the disconnect switch.
This might not be the best way. But I put the switch next to the seat plug and was able to reroute the cables so no new ones were needed. You use one of the switch cables to bridge across the space between the batteries where the switch was(I removed the frame plate) and then take the front cable loose from the second battery on the right and the use the other switch cable to connect the switch back to the battery. I had to fish the cable around the handbrake to do this. I covered the cable with some tygon tubing for extra insulation where it touches the hand brake frame for extra safety and the cable that jumps the two batteries where the switch was. It makes no difference where you brake the chain. I don’t care about charging the batteries when the switch is open. Other wise you need to make an extra cable up so you can break connection at the negative of #1 battery like Daniel did or for the six battery monitor. I find that the pack doesn’t loose charge for weeks if disconnected.
When I converted to lithium, I had to move my main disconnect switch, also near the charging socket. This does not spit the pack exactly in half anymore, but it’s a 4/2 split, and under the NEC 50 Volt DC limit for the longer string.