Do you recommend for a Jeep?

@@sebterror you can certainly use BLUETOP batteries in a Jeep, but we offer YELLOWTOP batteries in all the same sizes and in many cases, they offer a longer free-replacement warranty (three years vs two years) www.optimabatteries.com/products/yellowtop/

That is our recommendation, especially for winches, but you may be ok with a stereo system

The 34 REDTOP is the same battery as the 34M, but carries an additional year of free replacement warranty coverage. However, if you are connecting that battery to a winch or any other significant electrical accessories, we would recommend a D34 YELLOWTOP, which also offers three years of free replacement warranty coverage. On the house battery, it's difficult to know how much demand you will place on the battery, but Peurket's Law indicates the shallower the discharge cycle, the more cycle life you will see out of a lead-acid battery (including AGM batteries). That would suggest the best course of action would be to use the physically largest battery you can fit in the space available, so it will not only have more reserve capacity, but shallower discharge cycles than a smaller battery and longer lifespan. Whether it's the starting battery or the house battery, the key to maximizing battery performance and lifespan, is keeping your batteries fully-charged whenever possible. The REDTOP (and 34M BLUETOP) is considered fully-charged at about 12.6-12.8V and the YELLOWTOP (and all other BLUETOPs) is considered fully-charged at about 13.0-13.2V.

Either the D34M, D27M or D31M (smallest to largest). All of those batteries are designed & warrantied for deep-cycle use. The 34M BLUETOP is only designed & warrantied for use as a starting battery and would not be appropriate. The larger the battery, the more power it can deliver and in a constant application like a sump pump, the more cycle life you can get out of it. If your power goes out for an hour here or there, a D34M is probably fine. If it goes out for a day or longer, then a larger battery would be more appropriate www.optimabatteries.com/products/marine-rv

If an EV uses a 12-volt (low voltage) battery, it's possible an OPTIMA can be used in that application, if it meets or exceeds the specifications of the OE battery, fits in the space available and if properly-vented to the outside atmosphere, if necessary. Many newer vehicles have significant key-off loads, which is why 12-volt batteries are getting larger, even if the engines they start (in ICE applications) are getting smaller. We recommend periodic maintenance charging on all new vehicles, starting out with a monthly cadence and increasing or decreasing frequency, depending on measured voltage. Fully-charged, most 12-volt batteries will measure at least 12.6V and whenever any lead-acid battery is discharged below 12.4V and is left sitting in that state, sulfation begins forming, which diminishes both capacity and lifespan.

If you have enough time to charge them in between trips to the lake, the Digital 400 will work just fine to charge and maintain Group D31M BLUETOPs. However, if you are looking at using a trolling motor on back-to-back days, you'd want a charger that can charge at a higher rate. Our Digital 1200 charger will charge at a maximum of 12 amps, compared to just 4 amps for the Digital 400. There are also several reputable marine chargers that can charge at higher rates as well. We would encourage you to consider only units that are microprocessor-controlled and have specific settings for AGM (not gel or gel/AGM) batteries www.optimabatteries.com/products/digital-1200/

We've never heard of any AGM manufacturer offering over 100Ah in a Group 34 battery and frankly, we don't know how the math could possibly work in that footprint with lead-acid technology. Are you referring to the specification for minutes of reserve capacity? With that demand in a house bank, we'd recommend our Q31M-DC150, which is a 150Ah battery: www.optimabatteries.com/products/orangetop-q31m-dc150

@optimabatteries That's a lithium battery (not AGM) but OK. Two questions: Out of the claimed 150ah, how much of that is actually useable (in other words, maximum discharge over time). Secondly, can it be used for both deep cycle and start loads i.e could I replace my existing lead acid start battery and my existing lead acid house battery with one of these, to be charged in parallel (by solar or shore or alternator)?

@@optimabatteries Blue top C27M = 66ah. US Battery Group 27: 105ah. Northstar Group 31: 102ah (all c20 test).

Your first comment cited a D34M (Group 34) battery at 55Ah and suggested other manufacturers offer over 100Ah in that size. Neither the US Battery (Group 27) nor the Northstar (Group 31) you cited subsequently are Group 34 batteries.

@@stephenburnage7687 the Q31M-DP120 can be used in both starting and deep-cycle applications, although you'd want to confirm with the engine manufacturer on their requirements of lithium batteries. The Q31M-DP120 meets or exceeds Mercury's requirements from November 2022. The available cycle life of a lithium battery out of the box is far greater than a lead-acid battery. You will get the Ah specification listed out of either battery and while there is some penalty for deeply-discharging either technology, it is not as great a penalty for lithium. Also, lead-acid batteries will have a greater efficiency loss with higher rates of discharge than lithium batteries. www.optimabatteries.com/products/orangetop-q31m-dp120

We are not allowed to recommend products from other manufacturers. If you are looking for a charger to mount in a boat, we would recommend one that is microprocessor-controlled and has specific settings for AGM (not gel/AGM) batteries. There are many great options that offer both of those features.

5/16”-18UNC-2A threaded stainless steel stud.

Yes

So I have two of the dark gray one on a music system so really they not pushing no power out for what I need ?

@@sanchezfanning334 our 34M batteries with dark gray cases are designed & warrantied for starting applications only, not deep-cycle use, like car audio. If your engine is running and power is provided by your vehicle's charging system, you should be fine

I have had them last that long as well. They are the "honda" motors of the battery world.