Parallel Battery Connection

[Cyclezee]

I am setting up my recumbent trike and want to connect a 14Ah Li Po Ezee battery in parallel with the main battery to give extended range.

The Ezee battery normally sits on a contact plate, so I am thinking of buying an contact plate and wiring to make a parallel connection with the main battery and using a 32Ah MCB as an on/off isolating switch, then fitting these inside battery bag. I want to be able to remove the battery easily to use on my Forza, but at the same time have a secure connection with the contact plate.

As an alternative to buying a contact plate, I am also considering using 2 pins from a 13Ah domestic plug, these are the same dimensions as the poles on a contact plate, then custom making a 'plug' by moulding the pins in a block of visible light curing polymer or acrylic resin.

Has anyone done this before, or does someone have a better solution?

J hn

 

[NRG]

A few members have paralled batteries before so it can be done and your plan sounmds fine. Only thing I would add is a pair of ideal diodes to provide some isolation between the two, see:

http://www.pedelecs.co.uk/forum/classifieds/4531-ideal-diodes-battery-combining.html?highlight=ideal+diodes

 

[trickletreat]

I am setting up my recumbent trike and want to connect a 14Ah Li Po Ezee battery in parallel with the main battery to give extended range.

The Ezee battery normally sits on a contact plate, so I am thinking of buying an contact plate and wiring to make a parallel connection with the main battery and using a 32Ah MCB as an on/off isolating switch, then fitting these inside battery bag. I want to be able to remove the battery easily to use on my Forza, but at the same time have a secure connection with the contact plate.

As an alternative to buying a contact plate, I am also considering using 2 pins from a 13Ah domestic plug, these are the same dimensions as the poles on a contact plate, then custom making a 'plug' by moulding the pins in a block of visible light curing polymer or acrylic resin.

Has anyone done this before, or does someone have a better solution?

J hn

If you give the guys a call at On Bike, they did this for the Presteigne to the coast ride, on the Monday at the end of the Tour de Presteigne.

 

[hobo1]

John.

If it is of any help to you, on the On-Bike website there is a PDF file in the Tech Area Called wiring an Ezee Bike for parallel battery operation.
Was a great help to me when I wired up my Forza to run 24Ah parallel.

David.

 

[Cyclezee]

John.

If it is of any help to you, on the On-Bike website there is a PDF file in the Tech Area Called wiring an Ezee Bike for parallel battery operation.
Was a great help to me when I wired up my Forza to run 24Ah parallel.

David.

Thanks David, I have seen that already, but my setup is different because I am using the 14Ah battery as the 2nd battery and carrying it in a battery bag.

J hn

 

[Cyclezee]

A few members have paralled batteries before so it can be done and your plan sounmds fine. Only thing I would add is a pair of ideal diodes to provide some isolation between the two, see:

http://www.pedelecs.co.uk/forum/classifieds/4531-ideal-diodes-battery-combining.html?highlight=ideal+diodes

Thanks NRG,

I have emailed Nick re: Ideal Diodes, but I see that Onbike don't use them in their dual battery setup. I have also ordered a battery contact plate from Onbike, £10 + £4 delivery.

J hn

 

[hobo1]

John.

Mine is using a 10Ah & 14Ah, one on bike & one in pannier. Can be used either way round.

David.

 

[Cyclezee]

One more thing, does anyone know the gauge of cable used for conecting the battery?

J hn

 

[NRG]

John, the diodes are still a good idea to provide isolation and if using different batt types or capacities....

 

[Cyclezee]

John.

Mine is using a 10Ah & 14Ah, one on bike & one in pannier. Can be used either way round.

David.

I am setting up a trike David, primary battery on a rear rack and secondary battery in a battery bag, so not quite that simple.

J hn

 

[Scimitar]

If choosing an MCB to act as a switch or even a breaker, make sure you get one that can cope with DC. Many of them can't and you'll find the poles welded shut just when you need it to work. Marine and narrowboat chandlers are a source.
Regarding cable sizes, look at this for starters, cable chart is at the bottom of the page.
Auto Electrics Products Shop UK - Auto electrical Parts Suppliers Vehicle Wiring Workshop Supplies Retailer - Motor Car Electrics - Wire Distribution
Multi-stranded flex type is best.
or just google "auto electrical cable sizes uk"

 

[Cyclezee]

John, the diodes are still a good idea to provide isolation and if using different batt types or capacities....

Nick (Tiberius) doesn't have any Ideal Diodes available at the moment, but he did say "Ezee claim to have something in the newer battery packs that means you don't always need it".

Does anyone know anything about that?
I also see that Canadian Renaissance have discontinued Schottky Diodes.

So maybe diodes are no longer required, but I don't think I will risk it.

J hn

 

[flecc]

he did say "Ezee claim to have something in the newer battery packs that means you don't always need it".

Some of the latest BMS on quality batteries have reverse polarity protection, the Panasonic 10 Ah battery is like this. This means they can be connected in parallel without risk of cross charging.

I'd think it highly likely the top grade battery made by Advance which eZee and Wisper use is like this.
.

 

[Cyclezee]

Some of the latest BMS on quality batteries have reverse polarity protection, the Panasonic 10 Ah battery is like this. This means they can be connected in parallel without risk of cross charging.

I'd think it highly likely the top grade battery made by Advance which eZee and Wisper use is like this.
.

Thank you Tony, that is reassuring. I have sent email to Mr.Ching and will wait to hear before connecting up the 2nd battery.

Went for a short test ride this morning to see if everything worked and I am happy to say it does

I still quite a bit to do yet, tidying up and waterproofing the wiring, adding some links to the chain so I can get it on to the largest chainring.

Really glad the frame is black otherwise the wiring would have stood out like a sore thumb.

First impressions are the trike is going to a lot of fun

J hn

 

[Cyclezee]

Flecc was right, is he ever wrong?
Wai Won Ching has confirmed that diodes are not required when connecting Ezee batteries in parallel as reverse polarity protection is built in.

N.B. this applies to Ezee batteries, please check with suppliers of other brands before trying this.

Jhn

 

[piotrmacheta]

I connected 2 batteries in parallel in ignorance of this issue - lucky they were ezee ones! Worked very well as I recall.

 

[sir_round_hound]

Thank you Tony, that is reassuring. I have sent email to Mr.Ching and will wait to hear before connecting up the 2nd battery.

Went for a short test ride this morning to see if everything worked and I am happy to say it does

I still quite a bit to do yet, tidying up and waterproofing the wiring, adding some links to the chain so I can get it on to the largest chainring.

Really glad the frame is black otherwise the wiring would have stood out like a sore thumb.

First impressions are the trike is going to a lot of fun

J hn

I have a bottle battery with a broken charge port. Is cross charging a terrible thing?

 

[Deleted member 4366]

Probably. There's no safe alternative to charging through the two wires attached to the charge port. What do you mean by cross charging?