I used a Might-Max with Tru isolator, like many others here. Recently replaced the battery on our ride-on mower with a lithium ferrous phosphate battery (LiFePO4). Designed to last a whole heckofalot longer than lead acids, much lighter weight and can be fully discharged without cumulative damage (so long as it's charged back up soon-ish (unlike lead acids that loose capacity and life if discharged below 50% or so.
This one: Amazon.com
Note this was not used in my P-1000.
This one: Amazon.com
Note this was not used in my P-1000.
Vikes79
SKOL!
Lifetime Member
If I were to do my P1k5 again…I’d skip the isolator bs and go straight to a disconnect and a car battery under the drivers seat. If you got big continuous draws, you’ll hate the isolator.
Seriously…cheaper, and far cleaner.
My winch, heater, lights when im plowing snow absolutely make the isolator wigg out in short order.. I got the same problem when im spraying pastures at low ground speed and the cooling fan, under seat fan and my spraying pump are all running wide out.
last winter I just bypassed the isolator and paired up the two batteries. No problems since. I’d put a car battery under the seat, but I already have a heater there.
Just a contrary opinion from my experience.
Seriously…cheaper, and far cleaner.
My winch, heater, lights when im plowing snow absolutely make the isolator wigg out in short order.. I got the same problem when im spraying pastures at low ground speed and the cooling fan, under seat fan and my spraying pump are all running wide out.
last winter I just bypassed the isolator and paired up the two batteries. No problems since. I’d put a car battery under the seat, but I already have a heater there.
Just a contrary opinion from my experience.
There are a several concerns with your approach. Batteries for starting are typically rated in CCA or cold cranking amps. These lead/acid batteries are designed with thinner plates so as to get more plate area - this is a tradeoff, as thinner plates don't provide as much deep discharge capability. Lead acid batteries intended for deep discharge, as one may want to use for winching etc, will have thicker plates and accordingly less cold cranking ability.
New lead acid batteries start life with X amount of capacity. This generally improves a bit with the first few charge/discharge cycles - - then it's all downhill from there with the battery losing capacity over time.
Another big problem with your suggestion to simply connect the batteries in parallel, is that this should really only be done with two identical batteries of the same model and age. Otherwise, the internal battery resistance won't be the same and neither will the load capability - one battery will be discharging into the other to try to bring the levels to equilibrium. When charging, one battery will be overcharged while the other may not receive a full charge.
The Tru isolator, than many here have opted to use, allow two dissimilar* batteries to live together in harmony, so to speak, both getting charged properly from alternator or outside charger etc.
*Different ages, sizes and even types (Tru makes a mode for combining lead acid and lithium batteries as well.
Disclaimer: I'm no battery expert, though I've been in electronics in one form or another since the Navy trained me as an ET over 60 years ago. I've also been wrong now and then - just ask my wife.
Vikes79
SKOL!
Lifetime Member
Yeah then there’s reality. What do you think is happening when you connect a set of jumper cables…
By connecting them you’re expanding the reserve capacity…and yes they will level out like two tanks of water connected by a pipe over time.
It’s common practice in automotive and industrial applications….arguing about the age of the battery etc while it does matter some is splitting hairs when your rig is doa and your needing to get the job done. Your argument in the context of the nearly similar sized batteries in a P1k setup with and isolator is like saying if I mix brands of double AA batteries in my tv remote, my house will burn down.
Of course paired batteries should be replaced in pairs and matching size as best practice never said it wasn’t.
Right now you can walk into any Walmart and buy a basic group 24 battery for $65 bucks and park it under the drivers seat. Tray, cables, and battery you’d be into the battery for a bit more than the isolator kit on its own with FAR more AH capacity.
Sorry, but your battery jump start cable is a bogus example and analogy. In that specific situation you have an already dead battery and you want to get the dang thing running first and foremost. Besides, a dead lead acid battery has relatively high internal resistance, so when jumping the battery that tends to dampen any current inrush, so you typically get only a small spark upon connecting the two batteries. Besides, when you have a dead battery, you are not usually concerned with long-term battery health - that comes a bit later when you are buying a new one.
My previous post was intended to explain why it's normally considered poor practice to connect dissimilar batteries directly in parallel (or in series for that matter) if they are not the same brand, size, type and age. Do as you wish of course, but anyone following your advice should consider the downsides. The Tru, as well as other isolators, are popular here for some very good and valid reasons.
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