Batteries

[Shawhawk]

I got dumb rookie question/problem:

I have a 2011 Hino 338(straight truck) that has 3 950cca batteries and a forklift battery in the back(yes a forklift battery, dont know why but it just has one when i bought the truck) anyways the forklift battery died and i replaced it with a lower cca 700 i believe. Ever since then the truck started having a starting issue

Can i actually mix the 2 with a higher cca and a lower cca? Is it a bad idea?

Please help thanks

 

[Turtle]

Can i actually mix the 2 with a higher cca and a lower cca? Is it a bad idea?

The answer is YES to both questions. Yes, you can mix battery types and capacities, and yes, it's a really bad idea.

When you mix battery capacities in parallel, all of the batteries will effectively become the lower CCA in the circuit, in this case the three 950 CCA batteries become 700 CCA batteries.

Also, mixing old and new batteries will wear the new batteries out really quick. The new ones will cook due to overcharging while trying to bring the older, less capacity batteries in line with the new batteries (all batteries lose Ah capacity over time). In addition, during normal operations, the newer, more powerful batteries will constantly be trying to charge the lower capacity battery, further hastening their demise.

And if that's not enough, mixing batteries will unnecessarily overwork the alternator and shorten its life, too.

In short, replace all batteries at the same time, with the same type (chemistry, as in wet cell, AGM, etc.), brand, and capacity. It is also preferable that all of the batteries have the same date of manufacture. If you have 3 batteries made in Jan 2017 and one made in Dec 2016, that's OK. A month or two isn't that bid a deal. But 3 made in Jan 2017 and one made in Sep 2016 will shorten the life of all four batteries.

 

[Shawhawk]

I bought the 3 batteries back in Feb 2017 and the new one this month.

This morning i decided to remove the connection of the new battery(700cca) and go with the 3 950cca. I got it on battery charger right now. Hopefully everything will go back to normal