Thread: Auxiliary Battery Issues

Yellow top. Winner

I hire scissor lifts several times a year, the last time was Thursday week ago. I am not certain but I recall them saying 48 volts were required for most scissor lift and such electrical working equipment. 4 x 12 volt battery banks in the lifts I've hired I thought, to provide 48 volts I thought. The big units have special batteries, maybe branded by the lift company. I am amazed that a company like Coates would have gone for Optimas, as they are not high AH batteries, their benefit is (or was in some peoples' views here) fast recharge and lots of CCA plus deep cycle, plus they are rugged and heat tolerant. Really a hybrid - Bernal purpose battery. Which is far from IMO a true deep cycle, like what my battery uses.

I believe hire company's were using them in there internal combustion equipment as starter batteries, because of the way they recover after being discharged. Most hire ewp's run the beacon off the battery isolator not the ignition and they get left on over the weekend. That would kill a normal battery. Where a good optima would respond when back in the workshop hooked up and cooked in a ctek or similar

The electric gear I've seen runs 6v or 3 cell deep cycle battery's that are tall and skinny. They are usually Brown. Delkor or trojan maybe?

Originally Posted by josh.huber

I believe hire company's were using them in there internal combustion equipment as starter batteries, because of the way they recover after being discharged. Most hire ewp's run the beacon off the battery isolator not the ignition and they get left on over the weekend. That would kill a normal battery. Where a good optima would respond when back in the workshop hooked up and cooked in a ctek or similar

AHH that makes sense. I've not hired petrol operated gear for many years.

And with the 6v, I sort of recall seeing a 6V battery in a bank, but the memory is a bit vague. My presumption was 48 volts but maybe I heard wrong. If 6V that would mean 8 of them. I presume 6V is for packaging reasons? Or to keep the weight down when changing batteries?

In my van I had two failure of two 12v claimed 120 AH (they were less than that) deep cycle AGM batteries. I wanted more capacity but the space was limited and also the weight of bigger batteries becomes a real issue in a tight spot in a van. Also buying a pair of 120 AH deep cycle batteries is relatively cheap, but buying more than 120AH batteries and the price per AH goes up a fair bit. To go lithium would have cost me $5k due to the electrical change over required too (which is a lot of AGMs). The system is 12v so is in parallel with 12v. The charge would first enter one battery, and the negative exit was on the other battery. Both times the battery where the charge entered, was the battery that failed. I thought it too coincidental. (I still have one as a portable starter battery. Not super portable because its weight is 32kg.) So I put in much heavier cables linking the batteries. I really need to swap the batteries around IMO, say every 6 months or after each trip. Could give me a lot of extra life. But the other owners on our van's owners forum say that they have had failures on the charge battery too, which damaged my theory ... the new ones are Full River and they are a good battery it seems. So far ...

You’re on point when linking batteries in Parallel.

In my van I have 2x120ah in Parallel.

Battery 1 has the Pos feed with 2 B&S and a 2 B&S link with the Negative on Battery 2 and using the same 2 B&S cabling.

Power take off for the van are then done in the opposite fashion - Pos Battery 2, Neg battery 1.

I also kept all main cables identical length, even though over these short distances the losses are negligible.

Originally Posted by Tombie

You’re on point when linking batteries in Parallel.

In my van I have 2x120ah in Parallel.

Battery 1 has the Pos feed with 2 B&S and a 2 B&S link with the Negative on Battery 2 and using the same 2 B&S cabling.

Power take off for the van are then done in the opposite fashion - Pos Battery 2, Neg battery 1.

I also kept all main cables identical length, even though over these short distances the losses are negligible.

Mine are the same length too and all same diameter as yours. I have a swage tool but I did not make the cables up. And auto electricians don't want to do that sort of work either these days. Or guys who sell batteries it seems to me.

My issue though is that the battery that takes the positive charge in my parallel setup - same as yours Tombie - is the battery that has failed both times. This time I kept the other battery and although I don't use it much, it appears in fairly good condition. So firstly, why did one battery fail and the other wasn't too bad? And secondly, why did the one which takes the positive charge first, fail first? Both sets of times?

The factory also said don't forget - if you have a failed battery, you can run the system of just one battery ... which mean't to me, that single battery failures happen and the setups still work with one battery ... which meant to me that if a single battery is running the van setup by itself, that battery cannot be in too bad condition. Which mean't to me that premature battery failures are not that uncommon ... so how to avoid a premature battery failure in my van?

IMO the battery that takes the positive charge first is doing more work. (and the cabling linking the first battery to the second was lighter cable than 2 B&S hence the change). I even thought of trying to have longer cables for all the connections so I could swap the positive input batteries over, without moving the batteries, due to have extra long cables ... but that seemed messy alternative more work for me ... I will sway the batteries around though, despite having increased the cable thickness.

And Tombie, what sort of deep cycles are you running in your van? How long have they lasted? Just curious ...

Doug

I was running (when purchased) a couple of Exide AGMs which failed about 24 months ago.

They were replaced with Fusion 120ah units charged direct from the vehicle when running and via a Victron solar unit when not connected to the vehicle. A victron 240v 25a charger is installed for times where needed.

A fridge and other accessories run 24/7 in the van. It has not been connected to mains since they were installed so is totally reliant on the solar set up.


Having a think about balancing the charge potentially using a Terminal bolt for both Neg and Pos and then Y off to each battery may assist in load sharing and take off the van supply from these junctions also - so draw is also from the Y feed.