Wiring a Votronic VCC 1212-30 to EBL99K

[Pebble99]

I am looking to buy a Votronic VCC 1212-30 B2B as I am upgrading my Gels to Lithium. My Globecar has the older EBL99 and has separate ground connections from the starter and leisure batteries running into the back of the EBL -VE connection. The Votronic instructions for option 2 (connection via EBL) assumes that there is a ground connection between the starter and leisure battery somewhere else in the van and there is only a single ground cable connected to the back of the EBL. I've been scratching my head trying to figure this out as my knowledge of electrics is very basic. I have attached a rough diagram showing how I intend to cable up the B2B to the EBL. Can anyone confirm whether my approach is correct or whether there is a better way of connecting via the EBL. Thanks.

 

[autorouter]

In a motorhome, like any vehicle, all the negative grounds are connected together. If they weren't, the alternator wouldn't charge the leisure battery. You just have to make sure that the wire carrying the amps is thick enough to avoid too much voltage drop.

It depends on where the B2B will be located. If it's next to the EBL, then for the starter positive, you could remove the EBL connection and wire it to the B2B. Then run a new wire to the EBL starter positive.

You could do exactly the same for the starter negative. Disconnect it, connect to the B2B, then run a new negative wire from the B2B to the EBL. No need to move the Leisure battery negative, leave it connected like the positive. This would avoid the the slight difficulty of connecting a third negative to an already full terminal connection.

I'm not sure whether this B2B has the two negative terminals isolated. If they are, you will need a short link between the two terminals. If they're not, a link will do no harm.

Isolated negatives are important for boats, to avoid problems like electrolytic corrosion. These B2Bs are used on boats too, so maybe they have isolated negatives. Either way, on a vehicle you just connect them all together.

 

[Pebble99]

In a motorhome, like any vehicle, all the negative grounds are connected together. If they weren't, the alternator wouldn't charge the leisure battery. You just have to make sure that the wire carrying the amps is thick enough to avoid too much voltage drop.

It depends on where the B2B will be located. If it's next to the EBL, then for the starter positive, you could remove the EBL connection and wire it to the B2B. Then run a new wire to the EBL starter positive.

You could do exactly the same for the starter negative. Disconnect it, connect to the B2B, then run a new negative wire from the B2B to the EBL. No need to move the Leisure battery negative, leave it connected like the positive. This would avoid the the slight difficulty of connecting a third negative to an already full terminal connection.

I'm not sure whether this B2B has the two negative terminals isolated. If they are, you will need a short link between the two terminals. If they're not, a link will do no harm.

Isolated negatives are important for boats, to avoid problems like electrolytic corrosion. These B2Bs are used on boats too, so maybe they have isolated negatives. Either way, on a vehicle you just connect them all together.

Thanks. I believe the Votronic VCC 1212-30 does not have isolated negative terminals. I have attached a pic of the diagram from its manual which shows a connection from my understanding. I have followed your guidance and drawn a diagram (see option A attached) so would you mind checking it so that I have understood you correctly. I have also attached option B which is slightly different as the B2B OUT -VE connects directly to the leisure battery and not the EBL which is more aligned with the diagrams in the Votronic manual I think.

 

[paddymcc]

Option A will be fine with the 30A B2B and your connections look correct. On your first post you showed the connection for the D+ signal going to the B2B. I put a switch with a LED in this wire before the B2B so that I could turn the B2B on and off from the drivers seat. With lithium they are best stored at less than 100% and I have found that I often want to turn off the B2B on the way home after a trip to avoid a full charge.

 

[Pebble99]

Many thanks. Out of interest, is there anything wrong with option B so that I can understand the impact of the difference.

^{_{Subscribers  do not see these advertisements}}

 

[paddymcc]

Many thanks. Out of interest, is there anything wrong with option B so that I can understand the impact of the difference.

No, as long as the -ve wires are of adequate thickness and have good connections at all the terminals it doesn't really matter. As autorouter says, all the negatives connect together and are connected to the chassis via the earth strap from the starter battery